Hand grip strength and fatigability: correlation with clinical parameters and diagnostic suitability in ME/CFS.
Jäkel, Bianka, Kedor, Claudia, Grabowski, Patricia et al. · Journal of translational medicine · 2021 · DOI
Quick Summary
This study tested hand grip strength in ME/CFS patients compared to healthy people and cancer patients to see if it could help diagnose the condition. Researchers found that ME/CFS patients had weaker grip strength and their muscles got tired much faster during repeated squeezing tests. Importantly, their muscles also recovered more slowly after resting for an hour, suggesting that muscle fatigue is a real, measurable feature of ME/CFS.
Why It Matters
This research provides an objective, practical clinical test that could help diagnose ME/CFS and measure disease severity—addressing a major unmet need since ME/CFS currently lacks standardized biomarkers. The findings validate that abnormal muscle fatigue in ME/CFS is a measurable physiological phenomenon, not a psychological issue, which has important implications for patient recognition and clinical management.
Observed Findings
ME/CFS patients had significantly lower maximum grip strength (Fmax) and mean grip strength (Fmean) compared to healthy controls (p < 0.0001).
ME/CFS patients showed a higher Fatigue Ratio (strength decline during repeated squeezes) than healthy controls (p ≤ 0.0012).
Muscle recovery after 60 minutes was significantly impaired in ME/CFS patients compared to controls (p ≤ 0.0020).
Lower grip strength parameters correlated with greater disease severity, post-exertional malaise, muscle pain, and elevated creatinine kinase and lactate dehydrogenase after exertion.
Inferred Conclusions
Repeated grip strength testing is a sensitive diagnostic tool for identifying muscular fatigue and fatigability in ME/CFS.
Abnormal grip strength parameters provide an objective measure of disease severity in ME/CFS patients.
Muscular fatigue in ME/CFS is a quantifiable physiological phenomenon that can be assessed in clinical practice.
Remaining Questions
Does hand grip strength testing predict post-exertional malaise or help guide activity management in individual patients?
How do abnormalities in grip strength and recovery relate to microscopic muscle changes or metabolic dysfunction at the cellular level?
What This Study Does Not Prove
This study does not prove that hand grip testing is definitively diagnostic for ME/CFS, as it is cross-sectional and does not establish causation. The mechanism behind abnormal fatigability remains unclear, and findings from hand grip strength may not fully represent whole-body muscle function. The study also cannot determine whether these muscular changes are primary to ME/CFS or secondary consequences of the condition.