Grip force control during object manipulation in cervical myelopathy.

STUDY DESIGN: Cross-sectional research. OBJECTIVES: To objectively evaluate grip force (GF) control while holding a freely movable object in individuals with cervical myelopathy (CM). SETTING: Harunaso Hospital, Takasaki, Japan. METHODS: We studied 52 hands from 26 individuals with CM. Participants performed a grip-and-lift task by pulp pinch using the thumb and index finger before surgery. We monitored individual finger GF (N) during the first 3 s while lifting and holding an object. Correlations between the GF and other clinical tests were evaluated. A multiple stepwise regression analysis was used to examine the contribution of the GF to the severity of clinical symptoms. RESULTS: Thumb GF was negatively correlated with the 10-s test (rs = -0.32), and index finger GF was positively correlated with its cutaneous pressure threshold (rs = 0.34). Multiple regression for the severity of upper extremity symptoms revealed that the model including the GF had a larger adjusted R2 and a lower AIC value than that of conventionally used clinical tests. CONCLUSIONS: These results suggested that the assessment of individual finger GF control could provide an indicator of the clinical severity of upper extremity in individuals with CM.