Strengthening Benefits

  • Increase speed, efficiency, and precision of movement
  • Increase stability
  • Increase endurance
  • Increase size of muscle to meet demand
  • Improve circulation
  • Support and improve cardiovascular health
  • Improve posture - increase bone density
  • Reduce risk for overuse injury


Muscle Strengthening Methods

Neuromuscular electrical stimulation

Primarily used for muscle reeducation; timing of contraction


Slow tension build with sustained hold, followed by a slow release. "Rule of tens" - 2 second ramp up, 6 second hold, 2 second release; used when joint motion is contraindicated to prevent atrophy or loss of tensile strength from disuse and promote circulation


Progression: single angle submaximal, multiple angle submaximal, and multiple angle maximal


Muscle shortening producing enough force to produce joint motion


Deceleration, controlled lowering against gravity; stimulates contractile and non-contractile elements


Requires exercise equipment that maintains torque throughout the range of motion

Proprioceptive neuromuscular facilitation

Manual resistance applied to promote stability or motion depending on the target outcome


Goal is to focus maintaining a closed-chain position in varying levels of support


Muscle Tissue Pathology

Disuse Atrophy

  • The number of sarcomeres decrease with disuse
  • The size of muscle cells decrease with disuse
  • Connective tissue (non-contractile) loses its tensile strength with disuse
  • Muscle tissue becomes stiffer (i.e., loses elasticity) with disuse
  • Disuse can be result from acute injury, immobilization, primary disease, a secondary effect from disease, and/or a lifestyle choice
  • Fast twitch muscle fibers (Type II) atrophy faster than slow twitch (Type I)

Muscle Strain

  • Classifications range from overstretch to tissue failure (tear)
  • Most common site of strain is where the muscle and tendon connect ("musculotendinous")
  • May result when there is
    • repetitive overuse
    • sudden excessive loading beyond a muscle's capacity to resist the force
    • overstretching
  • Graded on a three-point scale: higher grade = more severe injury

 Review from PTA 101