Muscle Synergies and Movement Health

16th February 2018

Muscle Synergists: the body’s agents of action are the ‘barometers’ of Movement Health


  • Muscle synergist clinical assessment & retraining
  • Everybody moves differently: assess how and retrain the individual
  • Recurrence management


One, but not the same

Motor redundancy offers a world of movement solutions to solve the challenges of function. While traditional motor control research scratched its head at how the body could possibly organise such a dizzying array of options (Bernstein, 1967), more contemporary commenters have renamed ‘redundancy’ ‘motor abundance’ (Latash, 2012). This much more positive sounding term reflects the wealth of movement options available within the movement system. For example, may muscles can flex the hip. Possession of many muscles that may perform the same movement role allows for the formation of muscle synergies. When iliacus, rectus femoris, tensor-fascia latae, sartorius and pectineus actively shorten in the sagittal plane, hip flexion occurs (see eLeaning to explore why psoas didn’t make the list).


Yet, while these synergists may be momentarily united in task, they differ in many other ways; anatomically, biomechanically, and neuro-physiologically, synergists are discrete entities. Further clouding something as simple as hip flexion is the observation that depending on the speed, load, level of fatigue, presence of pain or pathology, history of injury or presence of restriction, the level of contribution both within and between these synergists can vary widely.

Kinetic Control’s ‘Muscle Synergies’ modules supplies therapists with a both framework of management and the clinical tools of assessment and retraining to make sense of this complexity, addressing symptoms, compromised function and recurrence. 

Classifying synergists: helping to read muscle synergies

These three modules evaluate the efficiency of each patient’s current muscle recruitment strategies. When inefficiency is identified, specific synergists are targeted through retraining interventions. These skills of evaluation, reasoning, and retraining/cueing the patient are successfully achieved by the end of the course, ready for Monday morning. Seems simple. Yet, questions arise as how to judge efficiency. When so many muscles can flex the hip, how can we discern if a patient’s strategy is efficient? Aiding the evaluation process is muscle role classification system (Comerford & Mottram, 2012).

This multi-factorial model is sensitive to the clear distinctions (anatomical, biomechanical, neuro-physiological) evident between synergists and their differential response to the presence of pain, pathology and fatigue. If we are slowly lifting (hip flexing) the leg against limb load alone, is it efficient to be observing significant contributions from synergists best suited to high force and high speed. Interestingly, these are also the synergists that are frequently contributing to a greater extent in the presence of hip and lumbar spine pain or pathology.

Therefore, it can be clinically inferred there is a mismatch between task and synergistic strategy. Retraining can then address what assessment has found.
Co-ordination and Synergies: a comparison

In contrast to Kinetic Control’s ‘Co-ordination Efficiency’ modules which offer an excellent symptoms management process, the ‘Muscle Synergies’ modules more successfully address recurrence, teaching patients to employ synergists efficiently. They offer clinical tools to assess and retrain recruitment strategies in the absence of a multi-measure battery of tests (such as EMG, ultrasound), honing understanding of how synergist’s roles differ, enhancing cueing, observation and teaching of movement for a wide patient group.


No need to sub-group when ‘N = 1’ includes everyone

While classifying synergists allows for movement efficiency to be rated, it is acknowledged everyone moves differently. Indeed, people exhibit such a diverse range of movement strategies that sub-grouping patients fails to recognise the unique aspects of the individual. For example, during testing, we may see 10 to 12 different ways to flex the right hip between 10 to 12 different patients. However, each of these options can be judged for efficiency and retrained based on the individual’s specific need. While ‘train movement, not muscles’ may sometimes be quoted from those with a perspective that little can be gained from considering the differences between synergists, literature continues to emerge (Webb et al., 2018) that shows the body’s agents of action (muscles) are advantaged to specific roles in function.

Harnessing this knowledge and learning how to read and influence these barometers of Movement Health clinically, ensures therapists use another tool at their disposal and every synergistic player in the team gets to play their best suited role.


Also see

Kinetic Control’s ‘Co-ordination Efficiency’ modules puts movement quality at the heart of the clinical assessment and retraining process - see more here.

And Synergies and Testing for Holistic Hamstring Health in the Clinic



Bernstein, N. (1967) The Coordination and Regulation of Movements. Pergamon Press, Oxford.

Comerford, M., & Mottram, S. (2012). Kinetic Control-E-Book: The Management of Uncontrolled Movement. Elsevier Health Sciences.

Latash, M. L. (2012). The bliss (not the problem) of motor abundance (not redundancy). Experimental brain research217(1), 1-5.

Webb, A. L., O’Sullivan, E., Stokes, M., & Mottram, S. (2018). A novel cadaveric study of the morphometry of the serratus anterior muscle: one part, two parts, three parts, four? Anatomical science international93(1), 98-107.

Keywords: Movement Efficiency, Kinetic Control Education, Movement Health