The relationship between upper leg muscle strength and walking capacity in persons with multiple sclerosis
Multiple Sclerosis Journal, 05/25/2012
Broekmans T et al. – Resistance training protocols may consider inclusion of exercises focusing on endurance knee extensor and isometric knee flexor strength when aiming to enhance walking capacity in persons with moderate ambulatory dysfunction.Methods
- An observational cross-sectional study design was applied.
- Upper leg muscle strength of 52 PwMS (Expanded Disability Status Scale, EDSS range 1.5-6.5) was measured using isometric (knee extensors and flexors) and isokinetic (knee extensors) dynamometry.
- Walking capacity was assessed using the Timed 25-Foot Walk, Timed Up and Go and Two Minute Walk Test.
- Subgroups with mild (EDSS 1.5-4.0, n=31) and moderate (EDSS 4.5-6.5, n=21) ambulatory dysfunction were distinguished, and results were hypothesized to differ depending on multiple sclerosis (MS)-related disability status.
- Correlation and regression analyses were performed on the data of the most affected leg.
- Greatest (r: 0.2-0.7) and significant Pearson correlation coefficients were found in the moderate compared to mild MS subgroup.
- Within knee extensor measurements, it was found that isokinetic endurance strength related best to walking capacity.
- When comparing maximal isometric strength measurements, knee flexors (r: 0.5-0.7) related better to walking capacity than knee extensors (r: 0.1-0.4).
- Regression analyses confirmed endurance knee extensor strength (25 %) and isometric knee flexor strength (40%) as main predictors for walking capacity.