Exercise prescription and specificity

Course objectives, Control of Human Movement 2

Tissue adaptations appear to be fairly specific. Exercise prescriptions produce changes that are specific to:
  1. muscle group
  2. joint angle or range of motion
  3. type of muscle action
  4. speed of muscle action
  5. muscle fiber type
  6. metabolic energy system

We can understand the anatomical basis of exercise specificity in several ways.

Different tasks entail different control problems, which people solve by activating muscles in different synergies:

  1. Knee extension against resistance in open and closed chain tasks elicits different muscle synergies. During closed chain knee extension, muscle activity is paradoxical."

  2. Trunk flexion in open chain ("sit-up") and closed chain ("reverse trunk curl") tasks also elicit different abdominal muscle synergies.

  3. Training a lateral weight shift in standing may not carry over to a similar weight shift in walking ( Winstein, Gardner, McNeal, Barto, & Nicholson, 1989).

  4. Upper extremity reaching tasks may involve muscle synergies among the rotator cuff, deltoid, and scapulothoracic muscles that some therapeutic tasks do not duplicate.

Motor learning research illuminates the selection of therapeutic tasks

So does the definition of a 1RM: Repetition maximum (RM): "maximal number of times a load can be lifted before fatigue using good form and technique (ACSM, 1998)."

"Good form and technique" includes control, the ability to solve a motor problem by activating muscles in appropriate synergies, with appropriate timing.

Bernstein, N. (1967). The coordination and regulation of movements. New York: Pergamon.

Winstein, C.J., Gardner, E.R., McNeal, D.R., Barto, P.S., & Nicholson, D.E. (1989). Standing balance training: Effect on balance and locomotion in hemiparetic adults. Archives of Physical Medicine & Rehabilitation, 70, 755-62.

Last updated 3-14-01 ©Dave Thompson PT
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