Continuous monitoring of upper-limb activity in a free-living environment: a validation study

Monitoring upper-limb activity in a free-living environment is important for the evaluation of rehabilitation. This study is a validation of the Strathclyde Upper-Limb Activity Monitor (SULAM) which records the vertical movement and position of each wrist, and assesses bimanual movement. Agreement between the SULAM and two independent video observers was assessed using interclass correlation coefficients (ICC) and the Bland and Altman method. Concurrent validity was very good for movement of each upper-limb (ICC > 0.9), and good for the vertical position of the wrist (ICC > 0.8 for wrist positions below the shoulder, ICC > 0.6 otherwise). The ICC was good (>0.8) for bimanual movement, however the SULAM systematically underreported this by approximately 15%. The SULAM could be a useful tool to assess upper-limb activity of clinical populations in their usual environment.