Predicting 'normal' grip strength for rheumatoid arthritis patients

Area of Science:

• Orthopedics
• Rheumatology
• Hand Surgery

Background:

• Rheumatoid arthritis (RA) significantly impacts hand grip strength and functional capacity.
• Accurate assessment of grip strength deviation from normal is crucial for effective RA management and treatment goal setting.
• Predicting normal grip strength can improve the evaluation of functional loss in RA patients.

Purpose of the Study:

• To identify anthropometric parameters that best correlate with grip strength in healthy individuals.
• To determine if these correlations are strong enough to predict normal grip strength in rheumatoid arthritis (RA) patients.
• To establish a baseline for assessing grip strength deficits in RA.

Main Methods:

• Grip strength (power, pinch, tripod) and anthropometric measurements (forearm/hand volume, circumference, length) were assessed in 81 healthy subjects.
• These parameters were correlated with grip strength in healthy subjects and compared to 83 RA patients.
• In RA patients, grip strength was also correlated with disease activity markers (mRAI, VAS).

Main Results:

• Strong correlations were found between grip strength and anthropometric variables in healthy subjects, with forearm and hand volume showing the highest correlation (r=0.729, r=0.638).
• RA patients exhibited significantly lower grip strength compared to healthy individuals.
• Disease activity markers negatively correlated with grip strength in RA patients, and dominant hand strength was reduced in patients compared to controls.

Conclusions:

• Simple anthropometric measurements, especially forearm and hand volume, are valuable for predicting normal grip strength in RA patients.
• These predictions can be utilized in clinical settings and research for baseline assessments.
• The findings support using anthropometry to better understand and manage functional impairments in RA.