Physiological anterior laxity in healthy young females: the effect of knee hyperextension and dominance

Abstract

Female athletes are more likely to sustain an anterior cruciate ligament (ACL) injury. Knee laxity, hyperextension and limb dominance have been suggested as possible factors contributing to the knee injury. The aims of this study were to investigate the physiological anterior knee laxity between the dominant and non-dominant limb and in healthy young females with and without hyperextension knees. Forty-two healthy young females, 21 with hyperextension knees, were recruited voluntarily for this study. The subjects were tested with KT-2000 knee ligament arthrometer at both knees with flexion 30 degrees to obtain the anterior tibial displacements at loadings of 45, 67, 89 and 134 N. The initial and terminal stiffnesses were further calculated and analyzed to demonstrate the differences in the characteristics of knee laxity between limbs and groups. The results showed that there was no significant displacement difference between hyperextension and non-hyperextension groups. However, different physiological anterior laxities were illustrated for the different limbs and groups. The non-dominant side of the hyperextension group had significantly smaller terminal stiffness than that of the non-hyperextension group. The dominant side of the hyperextension group had larger laxity than the non-dominant side in the higher loading conditions. These findings may explain hyperextension knees are at greater risk of sustaining an ACL injury.

Prevalence of generalised joint hypermobility in school-aged children from east-central European region

“…Consistent with the findings of previous studies [3,12], our study revealed the little evidence for laterality of hypermobility in school-aged children.…”

Epidemiology of generalized joint laxity (hypermobility) in fourteen‐year‐old children from the UK: A population‐based evaluation

“…In our study, there was little evidence for laterality of hypermobility, consistent with the findings of one previous small study but in contrast to another (22, 23). In addition, there was no evidence of an association with ethnicity, although only a small proportion of the ALSPAC cohort is nonwhite (3.7%).…”

“…There is also a suggestion that ethnic background can influence hypermobility (16, 17) and that generalized joint laxity is more common in ballet dancers (18), musicians (19), gymnasts (20), and swimmers (21). Contradictory results from some small studies have demonstrated greater degrees of joint laxity in either the dominant limb (22) or the nondominant limb (23). A lack of association with body weight has been reported consistently (8, 24, 25).…”

Physiologic Preoperative Knee Hyperextension Is a Predictor of Failure in an Anterior Cruciate Ligament Revision Cohort: A Report From the MARS Group

“…14 The risk factors that predispose a person to an ACL injury vary. It is well known that many knees passively extend past 0 degrees and that some, but not all, of these knees may have generalized laxity 9,13–15,23 . Knee hyperextension (HE) has been previously reported to be an intrinsic factor contributing to ACL injury 13,14 .…”