Establishment of regression-based isometric strength reference values for the upper limb in persons with multiple...

Area of Science:

• Neurology
• Rehabilitation Medicine
• Biomedical Engineering

Background:

• Muscle weakness significantly impacts persons with multiple sclerosis (PwMS), with ~60% experiencing upper limb (UL) dysfunction.
• Assessing UL strength is crucial for managing PwMS and setting realistic rehabilitation goals.

Purpose of the Study:

• To develop gender-specific regression-based prediction equations for maximal bilateral UL isometric strength and hand grip strength in PwMS.
• To provide 95% confidence intervals for these strength measures.

Main Methods:

• A cross-sectional study involving 256 PwMS at a comprehensive MS center.
• Measured isometric strength (shoulder, wrist) and hand grip strength.
• Generated regression equations using demographics (age, height, weight) and disease characteristics (disability, disease duration) as covariates.

Main Results:

• Developed gender-specific predictive equations for UL muscle strength, accounting for age, height, weight, disability, and disease duration.
• Found maximal voluntary contraction (MVC) was higher in men than women (p < .001).
• MVC was significantly related to age and disability, but not disease duration.

Conclusions:

• This study provides the first regression-based prediction equations for UL muscle strength in PwMS.
• Demonstrated an inverse relationship between MVC with disability and age.
• Reference strength values aid clinicians in understanding PwMS muscular strength, goal setting, and patient education.