Biomechanical Analysis of the Knee Joint Load During a Unilateral Sit-to-Stand Movement
Hannah Steingrebe1, *, Thorsten Stein2, Klaus Bös2, Marian Hoffmann2
Background and Objectives:
Sit-to-Stand (STS) movements are fundamental activities of daily living. As STS movements can be physically demanding especially for the elderly, bi- and unilateral STS movements are frequently used in motor tests to measure leg strength. In contrast to bilateral STS movements, the knee joint loads occurring during unilateral STS movements as well as the influences of chair height or leg dominance are still unknown.
In a randomized study approach, knee joint loads during unilateral STS movements from three different chair heights have been analyzed using biomechanical motion analysis in a population of 19 healthy middle-aged adults. Additionally, the influence of leg dominance and the level of perceived exertion have been investigated.
Leg dominance had no effect on knee joint load, determined via peak knee moments and forces during unilateral STS movements. In contrast, chair height significantly affected the peak shear forces in the anterior and lateral direction as well as the peak knee adduction moment. Additionally, chair height but not leg dominance significantly affected the level of perceived exertion.
Discussion and Conclusion:
The detected knee joint loads occurring during unilateral STS movements are similar to those of other activities of daily living like e.g. stair ascent and thus, unilateral STS movements are applicable for usage in motor tests for middle-aged subjects. While leg dominance has no impact on the knee joint load, lower chair heights increase the acting sheer forces and joint moments. Therefore, chair height should be considered when using unilateral STS movements in motor tests.
Correspondence: Address correspondence to this author at the Engler-Bunte-Ring 15 Building 40.40, Room 105 76131 Karlsruhe, Germany; Tel: +49 721 608-41735; Fax: +49 721 608 – 44841; E-mail: email@example.com