The objective of this study was to evaluate the effects of a warm-up program on knee joint position sense in karatekas. Participants: Ten young amateur karatekas (17.6 +/- 4.0 years of age). Knee joint position sense evaluated before and immediately after a warm-up program through active repositioning in open kinetic chain (OKC) and closed kinetic chain (CKC). At baseline testing no differences were observed between OKC and CKC in absolute (4.1 +/- 1.6 degrees vs. 3.4 +/- 2.0 degrees ) and relative angular errors (2.4 +/- 3.4 degrees vs. 2.1 +/- 3.5 degrees ). After the warm-up program, a significant decrease in absolute angular error was observed only in CKC (from 3.4 +/- 2.0 degrees to 1.8 +/- 0.5, p < 0.05). Additionally, in CKC the subjects reduced the relative angular error to approximately zero (from 2.1 +/- 3.5 degrees to -0.01 +/- 1.6 degrees ) and decreased the variability of the responses, expressed by the decrease in standard deviation of the relative errors.
The warm-up program enhanced knee joint position sense only in CKC. Since no effects were detected in OKC, the evaluation of the effects of warm-up on knee joint position sense using merely an OKC technique would underestimate the valuable role of warm-up.