RH16
Associations Between Myotonometry and Other Upper Extremity Measures Among Persons with Multiple Sclerosis
Associations Between Myotonometry and Other Upper Extremity Measures Among Persons with Multiple Sclerosis
Thursday, June 2, 2016
Exhibit Hall
Background: Due to central nervous system involvement, a common symptom of multiple sclerosis (MS) is hypertonia, such as spasticity. Clinical measures of spasticity lack sensitivity and specificity, leading to the search for improved outcome measures to assess increased tone and its functional implications. Newer non-invasive myotonometry techniques can measure biomechanical properties of muscle tone and stiffness. To our knowledge, the association between myotonometry and other upper extremity (UE) measures in pwMS has not been examined. Objectives: To assess the association between myotonometry and other UE measures in pwMS. Methods: n=230 randomly selected pwMS had relaxed and maximally contracted myotonometry measures of frequency [freq], Hz and stiffness [stiff], N/m of the biceps brachii, long head, (bicep) and the extensor digitorum (ED). Other UE function measures included: Nine Hole Peg Test (NHPT), Box and Block test (BBT), grip strength, and grip endurance. Measures were completed on the dominant (D) and non-dominant (ND) sides. Data were analyzed using linear regression models in SPSS v22. Results: The following associations (beta, p-value) were seen: In the relaxed state, myotonometry measures of both muscle groups were associated with NHPT, BBT and grip strength. Bicep stiff was associated with NHPT (D: 0.229, 0.002), BBT (D: -0.280, 0.000; ND: -0.228, 0.003), and grip strength (D: -0.157, 0.026). Bicep freq was associated with NHPT (D: 0.177, 0.008) and BBT (D: -0.161, 0.016; ND: -0.197, 0.002). ED stiff was associated with grip strength (D: -0.215, 0.002; ND: -0.347). ED freq was associated with NHPT (ND: 0.132, 0.048), BBT (ND: -0.220, 0.001), and grip strength (D: -0.162, 0.014; ND: -0.289, 0.000). In the contracted state, both muscle groups were associated with grip strength but ED is most associated with NHPT, BBT and grip endurance. Bicep stiff was associated with grip strength (D: 0.229, 0.000; ND: 0.156, 0.017). Bicep freq was associated with grip strength (D: 0.149, 0.034). ED stiff was associated with NHPT (D: -0.263, 0.000; ND: -0.191, 0.007), BBT (D: 0.232, 0.001, ND: 0.223, 0.001), grip strength (D: 0.158, 0.014; ND: 0.268, 0.000) and grip endurance (D: 0.0189, 0.005; ND: 0.157, 0.026). ED freq was associated with NHPT (D: -0.166, 0.020), grip strength (D: 0.225, 0.002), and grip endurance (D: 0.142, 0.048; ND: 0.151, 0.043). Conclusions: Findings support associations between myotonometry and other UE measures in pwMS.