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The immediate effects of open kinetic chain knee extensor exercise at different loads on knee anterior laxity in the
Andrew Nicholettos1, Massimo G Barcellona, Matthew C Morrissey
1British School of Osteopathy, 275 Borough High Street, London, SE1 1JE, UK.
Background:
There is evidence that anterior laxity may be affected by knee extensor open kinetic chain (OKC) exercise with responses being load-dependent. The aim of this study is to evaluate the immediate and short-term changes in passive knee anterior laxity following a single session of OKC knee extensor exercise.
Methods:
Thirty two participants were randomly allocated to perform either high load (20 sets of 2 repetitions) or low load (2 sets of 20 repetitions) knee extensor OKC exercise with knee anterior laxity assessed before exercise, immediately after exercise and 45 and 90min after exercise with a KT-2000 arthrometer using a 133N force.
Results:
A significant effect of time was observed on knee laxity (p<0.001). However, a significant interaction of time and group was not found (p=0.54) and so the results presented here are for the combined (low and high load) group mean±standard deviation knee anterior laxity (mm) in the exercised leg: 7.2±2.2 (baseline), 8.2±2.3 (immediate post exercise, 14% change from baseline), 8.1±2.3 (45min post exercise, 12% change from baseline), and 7.7±2.2/0.29 (6.9) (90min post exercise, 7% change from baseline).
Conclusion:
OKC knee extensor exercise at high loads and low loads causes an immediate increase in knee laxity that begins to decrease within 90min.
