Postural Behaviour in Static Reaching Sidewards

This paper describes postural behaviour in static reaching sidewards, and the role of the trunk in particular. It turned out that the trunk (chest, pelvis) is not involved when reaching sidewards up to roughly 40-50° (depending on the reach distance). At greater angles the arm, the chest, and the pelvis each contribute at a particular rate to get the index finger onto target. These rates are reasonably similar to the average contributions of the arm, chest, and pelvis to the total of the range of motions of the arm, chest, and pelvis, suggesting that these segments share the musculoskeletal load equally.