Joint motion and reacting forces in the carving ski turn compared with the conventional ski turn

Abstract

Joint angle motion and reacting forces in the ski turn using a ‘carving ski’ with short side curve radius have been measured to be compared with those in a turn using a conventional ski which has a long side curve radius. The measurements were made using specially developed joint angle sensors attached to the skier’s leg and a force sensor fitted between the binding plate and the ski. In a long turn using a carving ski, the skier creates a larger difference between the outer leg extension and the inner leg flexion with no thigh rotation. Reacting force is uniform in the outer ski and also applied on the rear of the inner ski. However, the forward resistant force is larger in the carving ski turn. In the case of a long turn using a conventional ski, there is thigh rotation, larger abduction and smaller difference between the flexion of both legs. A relatively large force is applied to the front part of the ski. The joint motion in the carving ski turn is simple and it is easy for skiers to turn without skidding in the parallel long turn. In the short turn using a carving ski, the skier makes a gradual change in the thigh rotation. The outer leg continues flexion when it changes to the inner leg. Force also changes gradually over a small range. In the short turn using a conventional ski, the skier makes a quick rotation of the thigh in the early part of the turn. The reacting force occurs instantly and its amplitude of change is larger. The joint motion using the carving ski is moderate with no impact resistance. This will help skiers to make smooth and effective short turns.