Muscle memory: Difference between revisions

Content deleted Content added

Inline

Revision as of 20:27, 24 March 2010

Muscle memory, also known as motor memory, is a form of procedural memory that involves consolidating a specific motor task into memory through repetition. When a movement is repeated over time, a long-term muscle memory is created for that task; eventually allowing it to be performed without conscious effort. This process decreases the need for attention and creates maximum efficiency within the motor and memory systems. Examples of muscle memory are found in many everyday activities that become automatic and improve with practice, such as riding a bicycle or typing on a keyboard. ^[1].

History

Movement and Motor Learning

Movement is a critical part of our life, and it is a major component of our evolutionary development; without it, we could not survive.^[2] It has been suggested that our developed cognitive capacities evolved so we could make movements essential to our survival. For example, cognitive abilities evolved so we could use tools, build shelter, and hunt for animals.

The origins of research for the acquisition of motor skills stem from philosophers such as Plato, Aristotle and Galen. Friedrich Bessel is a philosopher who is especially noteworthy, as he was among the first to empirically observe motor learning. Bessel tried to observe the difference in his colleagues with the method in which they recorded the transit time of stars.^[2] After the break from tradition of the pre-1900’s view of introspection, psychologists emphasized research and more scientific methods in observing behaviours.^[3] Thereafter, numerous studies exploring the role of motor learning were conducted. Such studies included the research of handwriting, and various practice methods to maximize motor learning.^[2]

Retention

The retention of motor skills, now referred to as muscle memory, also began to be of great interest in the early 1900’s. Most motor skills are thought to be acquired through practice; however, mere observation of the skill has lead to learning as well.^[4] Research suggests we do not start off with a blank slate in regards to motor memory although we do learn most of our motor memory repertoire during our lifetime.^[5] Movements such as facial expressions, which are thought to be learned, can actually be observed in children who are blind; thus there is some evidence for motor memory being genetically pre-wired.^[5]

In the early stages of empirical research of motor memory Edward Thorndike, a leading pioneer in the study of motor memory, was among the first to acknowledge learning can occur without conscious awareness.^[6] One of the earliest and most notable studies regarding the retention of motor skills was by Hill, Rejall, and Thorndike, who showed savings in relearning typing skills after a 25 year period with no practice.^[2] Findings related to the retention of learned motor skills have been continuously replicated in studies, suggesting that through subsequent practice, motor learning is stored in the brain as memory. This is why performing skills such as riding a bike or driving a car are effortlessly and ‘unconsciously’ executed, even if someone had not performed these skills in a long period of time.^[2]

Physiology

Motor Behavior

When first learning a motor task, movement is often slow, stiff and easily disrupted without attention. With practice, execution of motor task becomes smoother, there is a decrease in limb stiffness, and muscle activity necessary to the task is performed without conscious effort.^[7]   

Muscle Memory Encoding

The neuroanatomy of memory is widespread throughout the brain; however the pathways important to motor memory is separate from the medial temporal lobe pathways associated with declarative memory.^[8] As with declarative memory, motor memory is theorized to have two stages; a short term memory encoding stage that is fragile and susceptible to damage, as well as a long term memory consolidation stage which is more stable.^[9]

An image of the cerebellum highlighted in red — *Cerebellum* highlighted in red

The memory encoding stage is often referred to as motor learning, and requires an increase in brain activity in motor areas as well as an increase in attention. Brain areas active during motor learning include the motor and somatosensory cortices; however these areas of activation decrease once the motor skill is learned. The prefrontal and frontal cortices are also active during this stage due to the need for increased attention on the task being learned.^[7]  

The main area involved in motor learning is the cerebellum. Some models of cerebellar-dependent motor learning, particularly the Marr-Albus model, propose a single plasticity mechanism involving the cerebellar long term depression(LTD) of the parallel fiber synapses onto Purkinje cells. These modification in synapse activity would mediate motor input with motor outputs critical to inducing motor learning.^[10] However, conflicting evidence suggests that a single plasticity mechanism is not sufficient and a multiple plasticity mechanism is needed to account for the storage of motor memories over time. Regardless of the mechanism, studies of cerebellar-dependent motor tasks show that cerebral cortical plasticity is crucial for motor learning, even if not necessarily for storage.^[11]

The basal ganglia also play an important role in memory and learning; particularly in reference to stimulus-response associations and the formation of habits. The basal ganglia-cerebellar connections are thought to increase with time when learning a motor task.^[12]

Muscle Memory Consolidation

Muscle memory consolidation involves the continuous evolution of neural processes after practicing a task has stopped. The exact mechanism of motor memory consolidation within the brain is controversial; however most theories assume that there is a general redistribution of information across the brain from encoding to consolidation. Hebb's rule states that “synapitc connectivity changes as a function of repetitive firing.” In this case, that would mean that the high amount of stimulation coming from practicing a movement would cause the repetition of firing in certain motor networks; presumably leading to an increase in the efficiency of exciting these motor networks over time. ^[11] 

Though the exact location of muscle memory storage isn’t known, studies have suggested that it is the inter-regional connections that play the most important role in advancing motor memory encoding to consolidation, rather then decreases in overall regional activity. These studies have shown a weakened connection from the cerebellum to the primary motor area with practice; possibly because of a decreased need for error correction from the cerebellum. Conversely, the connection between the basal ganglia and the primary motor area is strengthen, suggesting the basal ganglia plays and important role in motor memory consolidation process. ^[11]

Athletic Training

When participating in any sport, new motor skills and movement combinations are frequently being used and repeated. All sports require some degree of strength, endurance training and skilled reaching, in order to be successful in the required tasks.

Evidence has shown that increases in strength occur well before muscle hypertrophy, and decreases in strength due to detraining or ceasing to repeat the exercise over an extended period of time precede muscle atrophy.^[13] Specifically, strength training enhances motor neuron excitability and induces synaptogenesis, both of which would help in enhancing communication between the nervous system and the muscles themselves. ^[13].

However, neuromuscular efficacy is not altered within a 2 week time period following cessation of the muscle usage; instead it is merely the neuron`s ability to excite the muscle that declines in correlation with the muscle`s decrease in strength.^[14] This confirms that muscle strength is first influenced by the inner neural circuitry, rather than by external physiological changes in the muscle size.

Reorganization of motor maps within the cortex are not altered in either strength or endurance training. However, within the motor cortex, endurance induces angiogenesis within as little as 3 weeks to increase blood flow to the involved regions.^[13] In addition, neurotropic factors within the motor cortex are upregulated in response to endurance training to promote neural survival.^[13]

Skilled motor tasks have been divided into two distinct phases; fast learning phase, in which an optimal plan for performance is established, and slow learning, in which longer term structural modifications are made on specific motor modules.^[15] Even a small amount of training may be enough to induce neural processes that continue to evolve even after the training has stopped, which provides a potential basis for consolidation of the task. Additionally, studying mice while they are learning a new complex reaching task, has found that “motor learning leads to rapid formation of dendritic spines (spinogenesis) in the motor cortex contralateral to the reaching forelimb”. ^[16] However, motor cortex reorganization itself does not occur at a uniform rate across training periods. It has been suggested that the synaptogenesis and motor map reorganization merely represent the consolidation, and not the acquisition itself, of a specific motor task.^[17] Furthermore, the degree of plasticity in various locations (namely motor cortex versus spinal cord) is dependent on the behavioural demands and nature of the task (i.e. skilled reaching versus strength training).^[13]

Whether strength or endurance related, it is plausable that the majority of motor movements would require a skilled moving task of some form, whether it be maintaining proper form when paddling a canoe, or bench pressing a heavier weight. Endurance training assists the formation of these new neural representations within the motor cortex by up regulating neurotropic factors that could enhance the survival of the newer neural maps formed due to the skilled movement training. ^[13]Strength training results are seen in the spinal cord well before any physiological muscular adaptation is established through muscle hypertrophy or atrophy. ^[13]The results of endurance and strength training, and skilled reaching, therefore combine to help each other maximize performance output.

Fine Motor Memory

Fine motor skills are often discussed in terms of transitive movements, which are those done when using tools (which could be as simple as a tooth brush or pencil).^[18] Transitive movements have representations that become programmed to the premotor cortex, creating motor programs which result in the activation of the motor cortex and therefore the motor movements.^[18] In a study testing the motor memory of patterned finger movements (a fine motor skill) it was found that retention of certain skills are susceptible to disruption if another task interferes with one’s motor memory.^[1] However, such susceptibility can be can be reduced with time. For example, if a finger pattern is learned, then another is learned six hours later the original pattern will still be remembered, while learning such patterns back to back may cause forgetting of the initial one.^[1] Furthermore, the heavy use of computers by recent generations has both positive and negative effects. It was found that one of the main positive effects is that it enhances fine motor skills of children.^[19] Repetitive behaviours, such as typing on a computer from a young age, can enhance such abilities. Therefore, by beginning computer use at an early age muscle memory may be activated earlier.

Music Memory

Fine motor skills are very important in playing musical instruments. It was found that muscle memory is relied on when playing the clarinet, specifically to help create special effects through certain tongue movements when blowing air into the instrument.^[20] Memorizing is done by muscles as a note is seen and recalled, its auditory pair is learned and is matched by fingers movements (a fine motor skill).^[21] When reproducing a motor action, you must have previous experience with it to memorize set actions. If there is no previous experience there will be no mental image of the motion, and therefore no actual movement.^[21]

Certain human behaviours, especially actions like the fingering in musical performances, are very complex and require many interconnected neural networks where information can be transmitted across multiple brain regions.^[22] It has been found that there are often functional differences found in the brains of professional musicians compared to other individuals. This is thought to reflect the musician’s innate ability which may be fostered by an early exposure to musical training.^[22] An example of this is bimanual synchronized finger movements which play an essential role in piano playing. It is suggested that bimanual coordination can only come from years of bimanual training, where such actions become adaptations of the motor areas.^[23] When comparing professional musicians to a control group in complex bimanual movements, professionals are found to use an extensive motor network much less than those non-professionals.^[23] This is because professionals rely on a motor system that has increased efficiency, and therefore those who are less trained have a network which is more strongly activated.^[23] It is implied that the untrained pianists have to invest more neuronal activity to have the same level of performance that is achieved by professionals.^[23] This, yet again, is said to be a consequence of many years of motor training and experience which helps form a fine motor memory skill of musical performance.

It is often reported that when a pianist hears a well-trained piece of music it can involuntarily trigger synonymous fingering.^[22] This implies there is a coupling between the perception of music and the motor activity of those musically trained individuals.^[22] Therefore, one’s muscle memory in the context of music can easily be triggered when one hears certain familiar pieces. Overall, long-term musical fine motor training allows for complex actions to be performed at a lower level of movement control, monitoring, selection, attention, and timing.^[23] This leaves room for musicians to focus attention synchronously elsewhere, such as on the artistic aspect of the performance, without having to consciously control one’s fine motor actions.^[23]

Gross Motor Memory

Gross motor skills are concerned with the movement of large muscles, or major body movements, such as those involved in walking or kicking, and are associated with normal development.^[24] The extent to which one exhibits gross motor skills depends largely on their muscle tone and the strength.^[24] In a study looking at people with Down Syndrome it was found that the pre-existing deficits, with regards to verbal-motor performance, has an impact on limiting the individuals transfer of gross motor skills following visual and verbal instruction to verbal instruction only.^[25] The fact that the individuals could still exhibit two of the three original motor skills may have been a result of positive transfer in which previous exposure allows the individual to remember the motion, under the visual and verbal trial, and then later perform it under the verbal trial. ^[25]

Learning in Childhood

The way in which a child learns a gross motor skill can impact how long it takes to consolidate it and be able to reproduce the movement. In a study with preschoolers, looking at the role of self-instruction on acquiring complex gross motor chains using ballet positions, it was found that the motor skills were better learned and remembered, with the self –instruction procedure, over the no self-instruction procedure.^[26] This suggests that the use of self-instruction will increase the speed with which a preschooler will learn and remember a gross motor skill. It was also found that once the preschoolers learned and mastered the motor chain movements, they ceased the use of self-instruction. This suggests that the memory for the movements became strong enough that there was no longer a need for self-instruction and the movements could be reproduced without it.^[26]

Impact of Alzheimer's Disease

It has been suggested that consistent practice of a gross motor skill can help a patient with Alzheimer’s Disease learn and remember that skill. It was thought that the damage to the hippocampus may result in the need for a specific type of learning requirement.^[27] A study was created to test this assumption in which the patients were trained to throw a bean bag at a target.^[27] It was found that the Alzheimer’s patients performed better on the task when learning occurred under constant training as opposed to variable. Also, it was found that gross motor memory in Alzheimer’s patients was the same as healthy adults when learning occurs under constant practice.^[27] This suggests that damage to the hippocampal system does not impair an Alzheimer’s patient from retaining new gross motor skills; implying that motor memory for gross motor skills is stored elsewhere in the brain.

Impairment

It is difficult to display cases of “pure” motor memory impairment because the memory system is so widespread throughout the brain that damage isn’t often isolated to one specific type of memory. Similarly, diseases commonly associated with motor deficits, such as Huntington's and Parkinson's disease, have a wide variety of symptoms and associated brain damage that make it impossible to pinpoint whether or not motor memory is in fact impaired. Case studies have provided some examples of how motor memory has been implemented in patients with brain damage.

Consolidation Deficit

A recent issue in motor memory is whether or not it consolidates in a manner similar to declarative memory; a process that involves an initial fragile learning period that eventually becomes stable and less susceptible to damage over time.^[1] An example of stable motor memory consolidation in a patient with brain damage is the case of Clive Wearing. Clive has severe antrograde and retrograde amnesia due to damage in his temporal lobes,frontal lobes and his hippocampi; which prevents him from storing any new memories and making him aware of only the present moment. However, Clive still retains access to his procedural memories, specifically the motor memories involved in playing the piano. This could be because motor memory is demonstrated through savings over several trials of learning, whereas declarative memory is demonstrated through recall of a single item^[1]. This suggests that lesions in certain brain areas normally associated with declarative memory would not affect motor memory for a well learned skill.

Dysgraphia for the Alphabet

Case study: 54 year old lady with known history of epilepsy

This patient was diagnosed with a pure form of dysgraphia of letters, meaning she had no other speech or reading impairments.^[28]Her impairment was specific to letters in the alphabet. She was able to copy letters from the alphabet; however, was not able to write these letters.^[28] She had previously been rated average on the Wechsler Adult Intelligence Scale's vocabulary subtest for writing ability comparative to her age before her diagnosis.^[28] Her writing impairment consisted of difficulty remembering motor movements associated with the letters she was supposed to write.^[28] She was able to copy the letters, and also form images that were similar to the letters.^[28] This suggests that dysgraphia for letters is a deficit related to motor memory.^[28] Somehow there is a specific portion of the brain related to writing letters, which is dissociated from copying and drawing letter like items.   

Popular Culture

Heroes (2006 - present)

Monica Dawson, a character from the hit show Heroes, has an incredible capability to replicate a movement after it has only been seen once. This is called adoptive muscle memory, which is also called muscle mimicry.^[29] This aspect of muscle memory is related to the more general theory of muscle memory, in that it is movement that is learnt and retained after observation, although not related to repeated practice. Monica realizes later in the show that she has the same capabilities of St. Joan; a super hero in the fictional comic book created for the purpose of Heroes which is called 9th Wonders!.^[29]

References

^ ^a ^b ^c ^d ^e Krakauer,J.W., & Shadmehr, R. (2006). Consolidation of motor memory. Trends in Neurosciences, 29: 58-64. Cite error: The named reference "Krakauer" was defined multiple times with different content (see the help page).
^ ^a ^b ^c ^d ^e Lee, D.T., & Schmidt, A.R. (2005). Motor Control and Learning: A Behavioural Emphasis. (4th ed). Windsor, ON: Human Kinetics
^ Adams, A.J. (1987). Historical Review and Appraisal of Research on the Learning, Retention, and Transfer of Human Motor Skills. Psychological Bulletins, 101(1), 41-74
^ Celnik, P., Classen, J., Cohen, G.L., Duque, J., Mazzocchio, R., Sawaki, L., Stephan, K., & Ungerleider, L. (2005). Formation of a Motor Memory by Action Observation. The Journal of Neuroscience, 25(41), 9339-9346
^ ^a ^b Flanagan, R.J., Ghahramani, Z., & Wolpert, M.D. (2001). Perspectives and Problems in Motor Learning. Trends in Cognitive Sciences, 5(11), 487-494
^ Shanks, D.R. & St. John, M.F. (1994). Characteristics of Dissociable Human Learning Systems. Behavioural and Brain Sciences, 17(3), 367-447
^ ^a ^b Shadmehr R, Holcomb HH. (1997). Neural correlates of motor memory consolidation. Science 227: 821-25.
^ Brashers-Krug, T, Shadmehr, R. and Bizzi, E. (1996). Consolidation in human motor memory. Nature. 382.
^ Atwell P.,Cooke S.,Yeo C. (2002). Cerebellar function in consolidation of motor memory. Neuron. 34:1011-1020.
^ Boyden,E., Katoh, A., Raymond, J.(2004). Cerebellum-dependent learning: the role of multiple plasticity mechanisms. Annu. Rev. Neurosci.27:581-609
^ ^a ^b ^c Ma, L., et al,. (2010). Changes in regional activity are accompanied with changes in inter-regional connectivity during 4 weeks motor learning. Brain Res. doi: 10.1016/j.brainres.2009.12.073
^ Packard, M., Knowlton, B. 2002. Learning and memory functions of the basal ganglia. Annu. Rev. Neuroscience. 25: 563-93.
^ ^a ^b ^c ^d ^e ^f ^g Adkins, DeAnna L., Boychuck, Jeffery. 2006. Motor training induces experience specific patterns of plasticity across motor cortex and spinal cord. Journal of Applied Physiology. 101: 1776-1782.
^ Deschenes Michael R., Giles Jennifer A. 2002. Neural factors account for strength decrements observed after short-term muscle unloading. The American Journal of Physiology - Regulatory, Integrative and Comparative Physiology. 282: R578-R583.
^ Karni, Avi, Meyer, Gundela. 1998. The acquisition of skilled motor performance: Fast and slow experience-driven changes in primary motor cortex. Procedings of the National Academy of Sciences. 861-868.
^ Xu, Tonghui, Perlik, Andrew J. 2009. Rapid formation and selective stabilization of synapses for enduring motor memories. Nature. 915-20.
^ Kleim Jerrery L., Hogg Theresa M. 2004. Cortical Synaptogenesis and Motor Map Reorganization Occur during Late, But not Early, Phase of Motor Skill Learning. The Journal of Neuroscience. 24:629-633.
^ ^a ^b Dowell, L. R., Mahone, E. M., & Mostofsky, S. H. (2009). Associations of postural knowledge and basic motor skill with dyspraxia in autism: Implication for abnormalities in distributed connectivity and motor learning. Neuropsychology, 23, 563-570.
^ Straker, L., Pollock, C., & Maslen, B. (2009). Principles for the wise use of computers by children. Ergonomics [Ergonomics], 52, 1386-1401
^ Fritz, C., & Wolfe, J. (2005). How do clarinet players adjust the resonances of their vocal tracts for different playing effects? Journal of the Acoustical Society of America,118, 3306-3315.
^ ^a ^b Smith, T. L. (1896). On muscular memory. American Journal of Psychology, 7, 453-490.
^ ^a ^b ^c ^d Kim, D., Shin, M., Lee, K., Chu, K., Woo, S., Kim, Y., Song, E., Lee, Jun., Park, S., & Roh, J. (2004). Musical Training-Induced Functional Reorganization of the Adult Brain: Functional Magnetic Resonance Imaging and Transcranial Magnetic Stimulation Study on Amateur String Players. Human Brain Mapping, 23, 188-199.
^ ^a ^b ^c ^d ^e ^f Haslinger, B., Erhard, P., Altenmüller, E., Hennenlotter, A., Schwaiger, M., von Einsiedel, H. G., Rummeny, E., Conrad, B., & Ceballos-Baumann, A. O. (2004). Reduced Recruitment of Motor Association Areas During Bimanual Coordination in Concert PianistsHuman Brain Mapping, 22, 206-215.
^ ^a ^b “Gross motor Skills – What are Gross Motor Skills (http://learningdisabilities.about.com/od/gi/p/grossmotorskill.htm)”
^ ^a ^b Meegan, S., Maraj, B. K.V., Weeks, D., Chua, R. (2006). Gross Motor Skill Acquisition in Adolescents With Down Syndrom. DownSyndrome and Practice 9(3), 75-80
^ ^a ^b Vintere, P., Hemmes, N. S., Brown, B. L., Poulson, C. L. (2004) Gross-Motor Skill Acquisition by Preschool Dance Stoudents Under Self-Instruction Procedures. Journal of Applied Behaviour Analysis 37(3), 305-322
^ ^a ^b ^c Dick, M. B., Shankle, R. W., Beth, R. E., Dick-Muehlke, C., Cotman, C. W., Kean, M. L. (1996). Acquisition and long-term retention of a gross motor skill in Alzheimer's disease patients under constant and varied practice conditions. The Journals of Gerontology: Series B Psychological sciences and social sciences, 51B(2), 103-111
^ ^a ^b ^c ^d ^e ^f Kapur, N., & Lawton, N.F. (1983). Dysgraphia for Letters: a Form of Motor Memory Deficit? Journal of Neurological Psychiatry, 46(6), 573-575
^ ^a ^b (http://www.wikipedia.com) search word: Monica Dawson

@@ Line 1: / Line 1: @@
+'''Muscle memory''', also known as [[motor memory]], is a form of [[procedural memory]] that involves consolidating a specific motor task into memory through repetition. When a movement is repeated over time, a long-term muscle memory is created for that task; eventually allowing it to be performed without conscious effort. This process decreases the need for attention and creates maximum efficiency within the motor and memory systems. Examples of muscle memory are found in many everyday activities that become automatic and improve with practice, such as riding a bicycle or typing on a keyboard. <ref name = "Krakauer"> Krakauer,J.W., & Shadmehr, R. (2006). Consolidation of motor memory. Trends in Neurosciences, 29: 58-64.</ref>.
-{{Citecheck|date=April 2008}}
+{{TOC left}}
+{{-}}
+== History ==
-{{Expert-verify|date=April 2008}}
+=== Movement and Motor Learning ===
+Movement is a critical part of our life, and it is a major component of our evolutionary development; without it, we could not survive.<ref name = "Lee"> Lee, D.T., & Schmidt, A.R. (2005). Motor Control and Learning: A Behavioural Emphasis. (4th ed). Windsor, ON: Human Kinetics</ref> It has been suggested that our developed cognitive capacities evolved so we could make movements essential to our survival. For example, cognitive abilities evolved so we could use tools, build shelter, and hunt for animals.
+The origins of research for the acquisition of motor skills stem from philosophers such as [[Plato]], [[Aristotle]] and [[Galen]]. [[Friedrich Bessel]] is a philosopher who is especially noteworthy, as he was among the first to empirically observe [[motor learning]]. Bessel tried to observe the difference in his colleagues with the method in which they recorded the transit time of stars.<ref name = "Lee"></ref> After the break from tradition of the pre-1900’s view of [[introspection]], psychologists emphasized research and more scientific methods in observing behaviours.<ref> Adams, A.J. (1987). Historical Review and Appraisal of Research on the Learning, Retention, and Transfer of Human Motor Skills. Psychological Bulletins, 101(1), 41-74</ref> Thereafter, numerous studies exploring the role of motor learning were conducted. Such studies included the research of handwriting, and various practice methods to maximize motor learning.<ref name = "Lee"></ref>
-'''Muscle memory''', also called '''[[neuromuscular]] facilitation''', is the neuromuscular system's memorization of [[motor skill]]s.
-==Overview==
+=== Retention ===
+The retention of motor skills, now referred to as muscle memory, also began to be of great interest in the early 1900’s. Most motor skills are thought to be acquired through practice; however, mere observation of the skill has lead to learning as well.<ref> Celnik, P., Classen, J., Cohen, G.L., Duque, J., Mazzocchio, R., Sawaki, L., Stephan, K., & Ungerleider, L. (2005). Formation of a Motor Memory by Action Observation. The Journal of Neuroscience, 25(41), 9339-9346</ref> Research suggests we do not start off with a blank slate in regards to motor memory although we do learn most of our motor memory repertoire during our lifetime.<ref name = "Flanagan"> Flanagan, R.J., Ghahramani, Z., & Wolpert, M.D. (2001). Perspectives and Problems in Motor Learning. Trends in Cognitive Sciences, 5(11), 487-494</ref> Movements such as facial expressions, which are thought to be learned, can actually be observed in children who are blind; thus there is some evidence for motor memory being genetically pre-wired.<ref name = "Flanagan"></ref>
-When an '''active''' person repeatedly trains [[locomotor system|movement]], often of the same activity, in an effort to stimulate the [[mind]]’s adaptation process, the outcome is to induce  [[physiological]] changes which attain increased levels of accuracy through repetition. Even though the process is really brain-muscle memory or motor memory, the colloquial expression "muscle memory" is commonly used.<ref>[http://www.newyorker.com/reporting/2007/07/30/070730fa_fact_mcgrath]</ref>
+In the early stages of empirical research of motor memory [[Edward Thorndike]], a leading pioneer in the study of motor memory, was among the first to acknowledge learning can occur without conscious awareness.<ref> Shanks, D.R. & St. John, M.F. (1994). Characteristics of Dissociable Human Learning Systems. Behavioural and Brain Sciences, 17(3), 367-447</ref> One of the earliest and most notable studies regarding the retention of motor skills was by Hill, Rejall, and Thorndike, who showed savings in relearning typing skills after a 25 year period with no practice.<ref name = "Lee"></ref> Findings related to the retention of learned motor skills have been continuously replicated in studies, suggesting that through subsequent practice, motor learning is stored in the brain as memory. This is why performing skills such as riding a bike or driving a car are effortlessly and ‘unconsciously’ executed, even if someone had not performed these skills in a long period of time.<ref name = "Lee"></ref>
-Individuals rely upon the mind’s ability to assimilate a given activity and adapt to the training. As the [[brain]] and [[muscle]] adapts to training, the subsequent changes are a form or representation of its muscle memory.
+==Physiology==
-There are two types of motor skills involved in muscle memory: fine and gross. Fine motor skills are very minute and small skills we perform with our hands such as brushing teeth, combing hair, playing [[darts]], using a pencil or pen to write, [[touch typing]], playing some [[musical instrument]]s, or even playing video games. Gross motor skills are those actions that require large body parts and large body movements as in the throwing sports such as [[bowling]], [[American football]], and [[baseball]], sports such as [[rowing (Sport)|rowing]], [[basketball]], [[golf]], [[martial arts]], and [[tennis]], and activities such as driving a car (especially one with a [[manual transmission]]), piloting aircraft, playing some musical instruments, and [[marksmanship]].
+===Motor Behavior===
+When first learning a motor task, movement is often slow, stiff and easily disrupted without attention. With practice, execution of motor task becomes smoother, there is a decrease in limb stiffness, and muscle activity necessary to the task is performed without conscious effort.<ref name = "Shadmehr">Shadmehr R, Holcomb HH. (1997). Neural correlates of motor memory consolidation. Science 227: 821-25.</ref>
+===Muscle Memory Encoding===
-Muscle memory is fashioned over time through repetition of a given suite of motor skills and the ability through brain activity to inculcate and instil it such that they become automatic.  To the beginner, activities such as brushing the teeth, combing the hair or driving a vehicle are not as easy as they look. As one reinforces those movements through repetition, the neural system learns those fine and gross motor skills to the degree that one no longer needs to think about them, but merely to react and perform appropriately.  In this sense, the muscle memory process is an example of automating an [[OODA loop]] insofar as one learns to observe, orient, decide, and act.
+[[File:Temporal lobe.gif|thumb|right|alt=An image of the temporal lobe highlighted in red|''[[Temporal Lobe]]'' highlighted in red]]
+The [[neuroanatomy of memory]] is widespread throughout the [[brain]]; however the pathways important to motor memory is separate from the medial [[temporal lobe]] pathways associated with [[declarative memory]].<ref> Brashers-Krug, T, Shadmehr, R. and Bizzi, E. (1996). Consolidation in human motor memory. Nature. 382.</ref>  As with declarative memory, motor memory is theorized to have two stages; a short term [[memory encoding]] stage that is fragile and susceptible to damage, as well as a long term [[memory consolidation]] stage which is more stable.<ref> Atwell P.,Cooke S.,Yeo C. (2002). Cerebellar function in consolidation of motor memory. Neuron. 34:1011-1020.</ref>
+[[File:Cerebellum.gif|thumb|left|alt=An image of the cerebellum highlighted in red|''[[Cerebellum]]'' highlighted in red]]
+The memory encoding stage is often referred to as [[motor learning]], and requires an increase in brain activity in motor areas as well as an increase in attention. Brain areas active during motor learning include the motor and somatosensory cortices; however these areas of activation decrease once the motor skill is learned. The prefrontal and frontal cortices are also active during this stage due to the need for increased attention on the task being learned.<ref name = "Shadmehr"></ref>
+The main area involved in motor learning is the [[cerebellum]]. Some models of cerebellar-dependent motor learning, particularly the Marr-Albus model, propose a single plasticity mechanism involving the cerebellar long term depression(LTD) of the parallel fiber synapses onto [[Purkinje cells]].  These modification in synapse activity would mediate motor input with motor outputs critical to inducing motor learning.<ref> Boyden,E., Katoh, A., Raymond, J.(2004). Cerebellum-dependent learning: the role of multiple plasticity mechanisms. Annu. Rev. Neurosci.27:581-609</ref> However, conflicting evidence suggests that a single plasticity mechanism is not sufficient and a multiple plasticity mechanism is needed to account for the storage of motor memories over time. Regardless of the mechanism, studies of cerebellar-dependent  motor tasks show that cerebral cortical plasticity is crucial for motor learning, even if not necessarily for storage.<ref name = "Ma"></ref>
-When one picks up a hair brush, one automatically has a certain motion, style, number of strokes, and amount of pressure as the hair is brushed without requiring conscious thought about each movement. Other forms of rather elaborate motions that have become automatic include [[Speech communication|speech]]. As one speaks, one usually does not consciously think about the complex tongue movements, synchronisation with vocal cords and various lip movements that are required to produce [[phoneme]]s, because of muscle memory. In speaking a language that is not one's native language, one typically speaks with an accent, because one's muscle memory is tuned to forming the phonemes of one's native language, rather than those of the language one is speaking. An accent can be eliminated only by carefully retraining the muscle memory. It is said that it takes about 740 of the same motions for your muscles to "memorize" the movements almost perfectly.
+The [[basal ganglia]] also play an important role in memory and learning; particularly in reference to stimulus-response associations and the formation of habits. The basal ganglia-cerebellar connections are thought to increase with time when learning a motor task.<ref> Packard, M., Knowlton, B. 2002. Learning and memory functions of the basal ganglia. Annu. Rev. Neuroscience. 25: 563-93.</ref>
-==Neuromuscular facilitation==
+===Muscle Memory Consolidation===
-Neuromuscular facilitation is the process by which a fixed size signal from [[motor neurons]] onto muscles causes an increase in the contraction of a muscle. This seems to occur because of an increased amount of [[acetylcholine]] being released onto the muscle cells for a signal of a fixed size.<ref>
+Muscle memory consolidation involves the continuous evolution of neural processes after practicing a task has stopped. The exact mechanism of motor memory consolidation within the brain is controversial; however most theories assume that there is a general redistribution of information across the brain from encoding to consolidation.  [[Hebb]]'s  rule states that “synapitc connectivity changes as a function of repetitive firing.” In this case, that would mean that the high amount of stimulation coming from practicing a movement would cause the repetition of firing in certain motor networks; presumably leading to an increase in the efficiency of exciting these motor networks over time.  <ref name= "Ma"> Ma, L., et al,. (2010). Changes in regional activity are accompanied with changes in inter-regional connectivity during 4 weeks motor learning. Brain Res. doi: 10.1016/j.brainres.2009.12.073</ref>
-{{cite web
-|url=http://jeb.biologists.org/cgi/content/full/207/1/11
-|title=MUSCLE MEMORY -- Dow 207 (1): 11 -- Journal of Experimental Biology
-|publisher=jeb.biologists.org
-|accessdate=2008-03-19
-|last=
-|first=
-}}
-</ref> This process may also be called muscle memory.
+Though the exact location of muscle memory storage isn’t known, studies have suggested that it is the inter-regional connections that play the most important role in advancing motor memory encoding to consolidation, rather then decreases in overall regional activity.  These studies have shown a weakened connection from the cerebellum to the primary motor area with practice; possibly because of a decreased need for error correction from the cerebellum. Conversely, the connection between the basal ganglia and the primary motor area is strengthen, suggesting the basal ganglia plays and important role in motor memory consolidation process. <ref name = "Ma"></ref>
-==Alternate context==
+===Athletic Training===
-Muscle memory in the context of weight-training and [[bodybuilding]] implies a different scenario than mere "instinctive" memorization of various motor skills. Muscle memory can also imply that muscle can be gained back rapidly<ref>
+When participating in any sport, new motor skills and movement combinations are frequently being used and repeated. All sports require some degree of strength, endurance training and skilled reaching, in order to be successful in the required tasks.
-{{cite web
-|url=http://jap.physiology.org/cgi/content/abstract/70/2/631
-|title=Journal of Applied Physiology, Vol 70, Issue 2 631-640
-|publisher=jap.physiology.org
-|accessdate=2008-12-05
-|last=
-|first=
-}}</ref> after one consistently trains for a given period of time, takes a pronounced break from weight-training (i.e. detrains), and then returns to weight-training, thus the muscle maintains "muscle memory" of its previous, superior conditioning.
+Evidence has shown that increases in strength occur well before muscle [[hypertrophy]], and decreases in strength due to detraining or ceasing to repeat the exercise over an extended period of time precede muscle [[atrophy]].<ref name = "Adkins"> Adkins, DeAnna L., Boychuck, Jeffery. 2006. Motor training induces experience specific patterns of plasticity across motor cortex and spinal cord. Journal of Applied Physiology. 101: 1776-1782.</ref> Specifically, strength training enhances [[motor neuron]] excitability and induces [[synaptogenesis]], both of which would help in enhancing communication between the nervous system and the muscles themselves. <ref name = "Adkins"></ref>. [[File:US Navy 071017-N-0995C-008 Chief Mineman Kevin Sperling, an officer recruiter at Navy Recruiting Processing Station Honolulu, presses two 105-pound dumbbells.jpg|thumb|right|alt=A navy man performs strength training exercises.|''[[Strength training]]''.]]However, neuromuscular efficacy is not altered within a 2 week time period following cessation of the muscle usage; instead it is merely the [[neuron]]`s ability to excite the muscle that declines in correlation with the muscle`s decrease in strength.<ref> Deschenes Michael R., Giles Jennifer A. 2002. Neural factors account for strength decrements observed after short-term muscle unloading. The American Journal of Physiology - Regulatory, Integrative and Comparative Physiology. 282: R578-R583.</ref> This confirms that muscle strength is first influenced by the inner neural circuitry, rather than by external physiological changes in the muscle size.
-==See also==
-* [[Cross education]]
+Reorganization of motor maps within the cortex are not altered in either strength or endurance training. However, within the motor cortex, endurance induces [[angiogenesis]] within as little as 3 weeks to increase blood flow to the involved regions.<ref name = "Adkins"></ref> In addition, neurotropic factors within the motor cortex are [[upregulated]] in response to endurance training to promote neural survival.<ref name = "Adkins"></ref>
-* [[Procedural memory]]
+Skilled motor tasks have been divided into two distinct phases; fast learning phase, in which an optimal plan for performance is established, and slow learning, in which longer term structural modifications are made on specific motor modules.<ref> Karni, Avi, Meyer, Gundela. 1998. The acquisition of skilled motor performance: Fast and slow experience-driven changes in primary motor cortex. Procedings of the National Academy of Sciences. 861-868.</ref> Even a small amount of training may be enough to induce neural processes that continue to evolve even after the training has stopped, which provides a potential basis for consolidation of the task. Additionally, studying mice while they are learning a new complex reaching task, has found that “motor learning leads to rapid formation of [[dendritic spines]] (spinogenesis) in the [[motor cortex]] contralateral to the reaching forelimb”. <ref> Xu, Tonghui, Perlik, Andrew J. 2009. Rapid formation and selective stabilization of synapses for enduring motor memories. Nature. 915-20. </ref>  However, motor cortex reorganization itself does not occur at a uniform rate across training periods. It has been suggested that the synaptogenesis and motor map reorganization merely represent the consolidation, and not the acquisition itself, of a specific motor task.<ref> Kleim Jerrery L., Hogg Theresa M. 2004. Cortical Synaptogenesis and Motor Map Reorganization Occur during Late, But not Early, Phase of Motor Skill Learning. The Journal of Neuroscience. 24:629-633.</ref>  Furthermore, the degree of plasticity in various locations (namely motor cortex versus spinal cord) is dependent on the behavioural demands and nature of the task (i.e. skilled reaching versus strength training).<ref name = "Adkins"></ref>
+Whether strength or endurance related, it is plausable that the majority of motor movements would require a skilled moving task of some form, whether it be maintaining proper form when paddling a canoe, or bench pressing a heavier weight. Endurance training assists the formation of these new neural representations within the motor cortex by up regulating neurotropic factors that could enhance the survival of the newer neural maps formed due to the skilled movement training. <ref name = "Adkins"></ref>Strength training results are seen in the spinal cord well before any physiological muscular adaptation is established through muscle hypertrophy or atrophy. <ref name = "Adkins"></ref>The results of endurance and strength training, and skilled reaching, therefore combine to help each other maximize performance output.
+==Fine Motor Memory==
+[[Fine motor skills]] are often discussed in terms of transitive movements, which are those done when using tools (which could be as simple as a tooth brush or pencil).<ref name = "Dowell"> Dowell, L. R., Mahone, E. M., & Mostofsky, S. H. (2009). Associations of postural knowledge and basic motor skill with dyspraxia in autism: Implication for abnormalities in distributed connectivity and motor learning. Neuropsychology, 23, 563-570.</ref> Transitive movements have representations that become programmed to the [[premotor cortex]], creating motor programs which result in the activation of the [[motor cortex]] and therefore the motor movements.<ref name = "Dowell"></ref> In a study testing the motor memory of patterned finger movements (a fine motor skill) it was found that retention of certain skills are susceptible to disruption if another task interferes with one’s motor memory.<ref name = "Krakauer">Krakauer, J.W., & Shadmehr, R. (2006). Consolidation of motor memory. Trends in Neurosciences, 29, 58-64.
+</ref> However, such susceptibility can be can be reduced with time. For example, if a finger pattern is learned, then another is learned six hours later the original pattern will still be remembered, while learning such patterns back to back may cause forgetting of the initial one.<ref name = "Krakauer"></ref> Furthermore, the heavy use of computers by recent generations has both positive and negative effects. It was found that one of the main positive effects is that it enhances fine motor skills of children.<ref> Straker, L., Pollock, C., & Maslen, B. (2009). Principles for the wise use of computers by children. Ergonomics [Ergonomics], 52, 1386-1401</ref> Repetitive behaviours, such as typing on a computer from a young age, can enhance such abilities. Therefore, by beginning computer use at an early age muscle memory may be activated earlier.
+===Music Memory===
+[[File:Playing the piano.jpg|thumb|right|alt=Bimanual synchronized finger movements play an essential role in piano playing.|Playing the piano requires complex actions]]
+Fine motor skills are very important in playing musical instruments. It was found that muscle memory is relied on when playing the clarinet, specifically to help create special effects through certain tongue movements when blowing air into the instrument.<ref> Fritz, C., & Wolfe, J. (2005). How do clarinet players adjust the resonances of their vocal tracts for different playing effects? Journal of the Acoustical Society of America,118, 3306-3315.</ref> Memorizing is done by muscles as a note is seen and recalled, its auditory pair is learned and is matched by fingers movements (a fine motor skill).<ref name = "Smith"> Smith, T. L. (1896). On muscular memory. American Journal of Psychology, 7, 453-490. </ref> When reproducing a motor action, you must have previous experience with it to memorize set actions. If there is no previous experience there will be no mental image of the motion, and therefore no actual movement.<ref name = "Smith"></ref>
+Certain human behaviours, especially actions like the fingering in musical performances, are very complex and require many interconnected neural networks where information can be transmitted across multiple brain regions.<ref name = "Kim"> Kim, D., Shin, M., Lee,  K., Chu, K., Woo, S., Kim, Y., Song, E., Lee, Jun., Park, S., & Roh, J. (2004). Musical Training-Induced Functional Reorganization of the Adult Brain: Functional Magnetic Resonance Imaging and Transcranial Magnetic Stimulation Study on Amateur String Players. Human Brain Mapping, 23, 188-199. </ref>  It has been found that there are often functional differences found in the brains of professional musicians compared to other individuals. This is thought to reflect the musician’s innate ability which may be fostered by an early exposure to musical training.<ref name = "Kim"></ref> An example of this is bimanual synchronized finger movements which play an essential role in piano playing. It is suggested that bimanual coordination can only come from years of bimanual training, where such actions become adaptations of the motor areas.<ref name = "Haslinger"> Haslinger, B., Erhard, P.,  Altenmüller, E.,  Hennenlotter, A.,  Schwaiger, M.,  von Einsiedel, H. G., Rummeny, E., Conrad, B., & Ceballos-Baumann, A. O. (2004). Reduced Recruitment of Motor Association Areas During Bimanual Coordination in Concert PianistsHuman Brain Mapping, 22, 206-215. </ref> When comparing professional musicians to a control group in complex bimanual movements, professionals are found to use an extensive motor network much less than those non-professionals.<ref name = "Haslinger"></ref> This is because professionals rely on a motor system that has increased efficiency, and therefore those who are less trained have a network which is more strongly activated.<ref name = "Haslinger"></ref>  It is implied that the untrained pianists have to invest more neuronal activity to have the same level of performance that is achieved by professionals.<ref name = "Haslinger"></ref> This, yet again, is said to be a consequence of many years of motor training and experience which helps form a fine motor memory skill of musical performance.
+It is often reported that when a pianist hears a well-trained piece of music it can involuntarily trigger synonymous fingering.<ref name = "Kim"></ref> This implies there is a coupling between the perception of music and the motor activity of those musically trained individuals.<ref name = "Kim"></ref> Therefore, one’s muscle memory in the context of music can easily be triggered when one hears certain familiar pieces. Overall, long-term musical fine motor training allows for complex actions to be performed at a lower level of movement control, monitoring, selection, attention, and timing.<ref name = "Haslinger"></ref> This leaves room for musicians to focus attention synchronously elsewhere, such as on the artistic aspect of the performance, without having to consciously control one’s fine motor actions.<ref name = "Haslinger"></ref>
+== Gross Motor Memory ==
+[[Gross motor skill]]s are concerned with the movement of large muscles, or major body movements, such as those involved in walking or kicking, and are associated with normal development.<ref name = "Gross">“Gross motor Skills – What are Gross Motor Skills (http://learningdisabilities.about.com/od/gi/p/grossmotorskill.htm)”</ref> The extent to which one exhibits gross motor skills depends largely on their muscle tone and the strength.<ref name = "Gross"></ref> In a study looking at people with Down Syndrome it was found that the pre-existing deficits, with regards to verbal-motor performance, has an impact on limiting the individuals transfer of gross motor skills following visual and verbal instruction to verbal instruction only.<ref name = "Meegan">Meegan, S., Maraj, B. K.V., Weeks, D., Chua, R. (2006). Gross Motor Skill Acquisition in Adolescents With Down Syndrom. DownSyndrome and Practice 9(3), 75-80</ref> The fact that the individuals could still exhibit two of the three original motor skills may have been a result of positive transfer in which previous exposure allows the individual to remember the motion, under the visual and verbal trial, and then later perform it under the verbal trial. <ref name = "Meegan"></ref>
+=== Learning in Childhood ===
+The way in which a child learns a gross motor skill can impact how long it takes to consolidate it and be able to reproduce the movement.  In a study with preschoolers, looking at the role of self-instruction on acquiring complex gross motor chains using ballet positions, it was found that the motor skills were better learned and remembered, with the self –instruction procedure, over the no self-instruction procedure.<ref name = "Vintere">Vintere, P., Hemmes, N. S., Brown, B. L., Poulson, C. L. (2004) Gross-Motor Skill Acquisition by Preschool Dance Stoudents Under Self-Instruction Procedures. Journal of Applied Behaviour Analysis 37(3), 305-322</ref> This suggests that the use of self-instruction will increase the speed with which a preschooler will learn and remember a gross motor skill. It was also found that once the preschoolers learned and mastered the motor chain movements, they ceased the use of self-instruction. This suggests that the memory for the movements became strong enough that there was no longer a need for self-instruction and the movements could be reproduced without it.<ref name = "Vintere"></ref>
+=== Impact of Alzheimer's Disease ===
+It has been suggested that consistent practice of a gross motor skill can help a patient with [[Alzheimer’s Disease]] learn and remember that skill.  It was thought that the damage to the [[hippocampus]] may result in the need for a specific type of learning requirement.<ref name = "Dick">Dick, M. B., Shankle, R. W., Beth, R. E., Dick-Muehlke, C., Cotman, C. W., Kean, M. L. (1996). Acquisition and long-term retention of a gross motor skill in Alzheimer's disease patients under constant and varied practice conditions. The Journals of Gerontology: Series B Psychological sciences and social sciences, 51B(2), 103-111</ref> A study was created to test this assumption in which the patients were trained to throw a bean bag at a target.<ref name = "Dick"></ref> It was found that the Alzheimer’s patients performed better on the task when learning occurred under constant training as opposed to variable.  Also, it was found that gross motor memory in Alzheimer’s patients was the same as healthy adults when learning occurs under constant practice.<ref name = "Dick"></ref> This suggests that damage to the hippocampal system does not impair an Alzheimer’s patient from retaining new gross motor skills; implying that motor memory for gross motor skills is stored elsewhere in the brain.
+== Impairment ==
+It is difficult to display cases of “pure” motor memory impairment because the memory system is so widespread throughout the brain that damage isn’t often isolated to one specific type of memory.  Similarly,  diseases commonly associated with motor deficits, such as [[Huntington's]] and [[Parkinson's disease]], have a wide variety of symptoms and associated brain damage that make it impossible to pinpoint whether or not motor memory is in fact impaired.  Case studies have provided some examples of how motor memory has been implemented in patients with brain damage.
+=== Consolidation Deficit ===
+A recent issue in motor memory is whether or not it consolidates in a manner similar to declarative memory; a process that involves an initial fragile learning period that eventually becomes stable and less susceptible to damage over time.<ref name = "Krakauer"></ref> An example of stable motor memory consolidation in a patient with brain damage is the case of [[Clive Wearing]]. Clive has severe antrograde and retrograde amnesia due to damage in his temporal lobes,frontal lobes and his hippocampi; which prevents him from storing any new memories and making him aware of only the present moment. However, Clive still retains access to his procedural memories, specifically the motor memories involved in playing the piano. This could be because motor memory is demonstrated through savings over several trials of learning, whereas declarative memory is demonstrated through recall of a single item<ref name = "Krakauer"></ref>.  This suggests that lesions  in certain brain areas normally associated with declarative memory would not affect motor memory for a well learned skill.
+=== Dysgraphia for the Alphabet ===
+Case study: 54 year old lady with known history of epilepsy
+This patient was diagnosed with a pure form of [[dysgraphia]] of letters, meaning she had no other speech or reading impairments.<ref name = "Kapur" >Kapur, N., & Lawton, N.F. (1983). Dysgraphia for Letters: a Form of Motor Memory Deficit? Journal of Neurological Psychiatry, 46(6), 573-575</ref>Her impairment was specific to letters in the alphabet. She was able to copy letters from the alphabet; however, was not able to write these letters.<ref name = "Kapur"></ref> She had previously been rated average on the [[Wechsler Adult Intelligence Scale]]'s vocabulary subtest for writing ability comparative to her age before her diagnosis.<ref name = "Kapur"></ref> Her writing impairment consisted of difficulty remembering motor movements associated with the letters she was supposed to write.<ref name = "Kapur"></ref> She was able to copy the letters, and also form images that were similar to the letters.<ref name = "Kapur"></ref> This suggests that dysgraphia for letters is a deficit related to motor memory.<ref name = "Kapur"></ref> Somehow there is a specific portion of the brain related to writing letters, which is dissociated from copying and drawing letter like items.
+== Popular Culture ==
+=== Heroes (2006 - present)===
+[[File:Heroeswiki logo.jpg|thumb|right|alt=heroes logo]]
+[[Monica Dawson]], a character from the hit show ''[[Heroes]]'', has an incredible capability to replicate a movement after it has only been seen once. This is called [[adoptive muscle memory]], which is also called muscle mimicry.<ref name = "Wiki">(http://www.wikipedia.com) search word: Monica Dawson</ref> This aspect of muscle memory is related to the more general theory of muscle memory, in that it is movement that is learnt and retained after observation, although not related to repeated practice. Monica realizes later in the show that she has the same capabilities of [[St. Joan]]; a super hero in the fictional comic book created for the purpose of ''Heroes'' which is called ''[[9th Wonders!]]''.<ref name = "Wiki"></ref>
+<br />
+== See Also ==
+#  [[procedural memory]]
+#  [[motor learning]]
+#  [[motor coordination]]
+#  [[muscle]]
+#  [[memory consolidation]]
+== References ==
-==References==
 {{reflist}}
+== Further Readings ==
+{{memory}}
+[[Category: Memory]]
 {{Muscular system}}

v t e Muscular system
Tissue	Muscle tissue Cardiac muscle Skeletal muscle Smooth muscle Fascia Superficial Deep Visceral Fascial compartment Arm Forearm Thigh Leg Tendon/Aponeurosis
Shape	Fusiform Pennate muscle Unipennate Bipennate
Other	Anatomical terms of muscle Origin Insertion List of muscles of the human body Composite muscle