Abstract
Background & Purpose
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.
Methods
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.
Conclusion
No differences were observed for lumbar extensor strength (P > 0.05) or the onset of muscular contraction (P > 0.05), though 95% confidence intervals revealed the difference in gluteus maximus onset time (−0.11 – 1.06 s) could be large and may have clinical importance. Descriptive data highlighted the prevalence of back pain was 40% greater in HSI participants.
Conflicts of interest
None
Sources of funding
This research was funded by the Wellcome Trust as part of their biomedical vacation award.
