Background

Strength is the force that a muscle or muscle group produces against resistance. Muscle-strength loss can decrease a person’s activity tolerance and can affect their ability to perform occupations. Muscle strength deficits are caused by many factors, including injuries, diseases, or immobilization. Diagnoses that affect muscle strength include lower motor neuron diseases, spinal cord injuries, muscular dystrophies, fractures, burns, arthritis, etc. Also, a person who is hospitalized and immobile for a long time after an illness or injury will experience muscle-strength loss. These diagnoses affect muscle strength, movement coordination, and range of motion, which all go hand in hand when performing an occupational activity.

Muscle-strength loss greatly impacts a person’s activities of daily living (ADL) and instrumental activities of daily living (IADL) occupation performance. As an occupational therapist (OT), your first action when seeing a new client is to screen for deficits that limit occupational function. General screening tests for strength deficits help you to determine weakness areas, which then help you to determine if a more precise assessment is needed. Manual muscle testing (MMT) is more precise because it targets specific muscle groups or muscles’ maximal strength. As the OT, you can then determine how to create an appropriate intervention specific to your client’s individual needs.

Screening for Strength Deficits

This video explains how to screen for strength deficits.

Video is licensed under CC BY 4.0.

Screening for Strength Video Transcript

Screening for Strength Tips

• Observe your client’s regular movements: pay attention to any movement, balance, or mobility limitations that could potentially affect their safety and independence.
• Pay attention to your client’s activity tolerance related to strength.
• Watch for signs of pain during your client’s movements.
• Perform an active range of motion (AROM) screen on your client. Check on bilateral upper extremities (UE); note any gross deficits.
• Remember that gross screening will not detect subtle deficits.
• Add resistance to motion screening to estimate muscle strength.

Manual Muscle Testing

This video explains how and why to perform manual muscle testing for strength deficits.

Video is licensed under CC BY 4.0.

Manual Muscle Testing Video Transcript

Manual Muscle Testing Tips

• Screen to determine the strength deficit.
• Perform MMT to quantify the strength deficit.
  • Test PROM to the affected limb to determine if it is a range of motion deficit.
  • Assess both body sides, beginning with the unaffected side to determine your client’s normal strength.
  • To test strength in a gravity minimized plane, position your client so that they are moving parallel to the floor.
  • To test strength against resistance, position the client so they are moving against gravity.
    • Use one hand to stabilize proximal to the moving joint.
    • Use the other hand to resist the movement distal to the moving joint. Be certain not to cross distal joints.
• Explain, always, what you are going to do and how you are going to do it.
• Form an occupational dysfunction hypothesis from your results.
• Ask your client what they desire to work on.
• Create a target intervention for your client’s specific needs.

Muscle Grades and Definitions

Table used pursuant to Fair Use.

Interventions for Strengthening

This video explains remedial interventions using therapeutic exercise for strengthening. 

Video is licensed under CC BY 4.0.

Interventions for Strengthening Video Transcript

Creating Interventions for Strengthening Tips

• Use remedial interventions to fix the problem or deficit.
• Begin with therapeutic exercise to improve strength and therapeutic activity.
  • Therapeutic exercises are general gym exercises.
  • Therapeutic activity is using an occupation with an activity that challenges strength.
• Increase resistance as strength increases, to where there is fatigue.
  • The “Just Right Challenge” is performing eight-to-ten reps, three times, which causes fatigue.
  • When using weights, the motion is against gravity.
  • When using resistance bands, gravity isn’t a factor.
  • Resistance bands only have resistance when there is stretch to the band.
  • Grade the exercise to create the right amount of resistance.

Resources

• Manual Muscle Testing, Physiopedia
• Performance Health Manual: Exercises by Performance Health