Associations Between UE Body Functions and Clinical Characteristics Among Persons with Multiple Sclerosis

Background: Relative to the lower extremity, we have less understanding of upper extremity (UE) involvement in persons with multiple sclerosis (pwMS). Better understanding of UE involvement in MS will help to prioritize the design and selection of future UE rehabilitative interventions. Objectives: To characterize UE body functions among pwMS receiving care at a comprehensive MS Center in New England, and to determine whether functions vary by age, gender, disability level, and disease duration. Methods: These data are part of a larger study designed to characterize the UE in MS across domains of the International Classification of Functioning, Disability & Health. Four hundred pwMS were randomly selected from the MS Center, of whom 267 (67%) agreed to participate. Participants completed comprehensive testing, including several measures of body functions: active range of motion (AROM) (shoulder, elbow, forearm, wrist and index finger), isometric arm strength (shoulder abduction and adduction, wrist flexion and extension), grip strength, grip endurance, coordination (finger to nose test), tremor (spiral drawing), vibration sensation (Vibratron II), and tactile sensation (monofilaments).  Most measures were assessed on both the dominant side (DS) and non-dominant side (NDS). Age, gender, disability level (EDSS), and disease duration were obtained from self-report or participants’ charts. Data were analyzed using t-tests/anova for normally distributed data and Kruskal-Wallis for non-normal data. Analyses were performed using SAS v9.4 and SPSS v22. Results: DS and NDS measures of AROM, strength, coordination, and vibration and tactile sensation were associated with age; only strength measures were associated with gender. DS and NDS measures of shoulder AROM, grip strength, coordination, and tactile sensation were associated with EDSS. DS and NDS measures of grip strength, coordination, and shoulder adduction and wrist flexion peak torque were associated with disease duration. Several DS measures of AROM, but only NDS wrist extension AROM, were associated with disease duration. Associations with disease duration and EDSS tended to vary by DS and NDS. Conclusions: Measures of UE body functions are associated with participant characteristics, mostly notably gender and age. Differences by gender are limited to strength measures, while age is associated with most measures. Associations of measures with disease duration and EDSS are less consistent.