The co-ordinated contraction of the kinetic chain is responsible for the dissipation of force. Weakness in the kinetic chain, such as the posterior oblique sling (POS), may increase the demand on additional muscles, such as the hamstrings, to compensate. The lumbar extensors may be particularly vulnerable in the kinetic chain, as they appear difficult to strengthen due to the dominant hip extensors. Therefore, this study aimed to investigate whether participants with a history of hamstring injuries presented with low back pain because of greater deficits in lumbar extensor strength, and impaired co-ordination of the POS. Twenty male footballers were recruited (n: Injured- 9, Controls- 11). Isolated lumbar extension strength, low back pain, and the contraction time of muscles within the POS during a hip extension test were recorded. Participants were then grouped in either the injury or control group.Background & Purpose
Methods