INTRODUCTION:
An assessment of muscle strength is typically performed as part of a patient's objective assessment and is an important component of the physical exam that can reveal information about neurologic deficits. It is used to evaluate weakness and can be effective in differentiating true weakness from imbalance or poor endurance. It may be referred to as motor testing, muscle strength grading, manual muscle testing, or any other synonyms. Muscle strength can be assessed by a number of methods-manually, functionally, or mechanically. Strength depends on the combination of morphological and neural factors including muscle cross-sectional area and architecture, musculotendinous stiffness, motor unit recruitment, rate coding, motor unit synchronization, and neuromuscular inhibition.
FUNCTION:
The function of muscle strength testing is to evaluate the complaint of weakness, often when there is a suspected neurologic disease or muscle imbalance/weakness. It is an important part of the assessment in many client groups including
- patients with stroke, brain injury, spinal cord injury, neuropathy, amyotrophic lateral sclerosis, and a host of other neurologic problems.
- rehabilitation after sporting injuries eg ACL repair
- after fractures and joint replacements eg TKR
- gait and balance problems in the older adult
- falls risk assessment
| Score | Description |
| 0 | No contraction |
| 1 | Flicker or trace of contraction |
| 2 | Active movement, with gravity eliminated |
| 3 | Active movement against gravity |
| 4 | Active movement against gravity and resistance |
| 5 | Normal power |
- Flicker of movement
- Through full range actively with gravity counterbalanced
- Through full range actively against gravity
- Through full range actively against some resistance
- Through full range actively against strong resistance
Commonly tested muscles include the shoulder abductors, elbow flexors, elbow extensors, wrist extensors, finger flexors, hand intrinsics, hip flexors, knee extensors, dorsiflexors, great toe extensor, and plantar flexors. These muscle groups are commonly chosen, so that important spinal nerve roots are assessed systematically eg testing the strength of the elbow flexors, elbow extensors, wrist extensors, finger flexors, and hand intrinsics allow for a methodical evaluation of the C5 to T1 nerve roots.
DYNAMOMETER:
Distal strength can be semiquantitatively measured with a handgrip ergometer (or with an inflated BP cuff squeezed by the patient) to record grip strength. Requires specialized equipment, most commonly dynamometers. Dynamometry is a more precise measurement of the force that a muscle can exert and can allow for differences in strength to be recorded over time. Expensive versions exist as do cheap versions as found on internet searches.
FUNCTIONAL TESTING:
Often provides a better picture of the relationship between strength and disability. As the patient does various maneuvers,deficiencies are noted and quantified as much as possible (eg 30 seconds sit to stand test, TUG.).
- Rising from a chair or stepping onto a chair tests proximal leg strength, walking on the heels and on tiptoe tests distal strength.
- Pushing with the arms to get out of a chair indicates quadriceps weakness.
- Swinging the body to move the arms indicates shoulder girdle weakness.
- Rising from the supine position by turning prone, kneeling, and using the hands to climb up the thighs and slowly push erect (Gowers sign and seen in Duchenne gait) suggests pelvic girdle weakness.
- The Manual muscle power testing Scale is commonly accepted and does not require special equipment, and demonstrates reasonable interrater reliability. More precise methods of measurement, such as hand-grip dynamometry, are less subjective and provide a quantifiable measurement that can be tracked over time. However, a cross-sectional study (2020) shows a lower correlation between the handgrip strength and standard strength measures of the lower limbs (hip, knee, and ankle extensor/flexor muscles), and functional capacity in older women.
- Functional assessment of strength focuses on how independently patients are able to perform their activities of daily living and whether strength is a limiting factor.
- Effect of Protein supplements on muscle-For untrained individuals, consuming supplemental protein likely has no impact on lean mass and muscle strength during the initial weeks of resistance training. Protein supplementation may accelerate gains in both aerobic and anaerobic power as the frequency, duration, volume of resistance training increase.
THOSE ABOVE ARE COLLECTED FROM SOME BOOKS AND
WEBSITES..
THANK YOU,
Comments