| This dissertation investigated the ability to predict knee valgus experienced during landing from a jump to knee valgus observed during a squat or the countermovement during the takeoff phase prior to a jump. In addition, the effect of hip internal and external rotator strength was also investigated. In Study 1, hip external rotator strength at 30° hip flexion and knee valgus during squatting explained 64% of the variance suggesting a good first step in developing a field test that can be used as a screening tool prior to sports participation. In Study 2, difference in landing mechanics following a squatting and running protocol were compared to the changes following participation in a basketball game. Changes in knee kinesthetic sense and landing mechanics following the running protocol were more similar to those following game participation suggesting the running protocol is a better simulator for athletic performance and thus was used the running fatiguing protocol during study 3. In Study 3, the ability to predict knee valgus following landing from squatting was confirmed in fatigued and non-fatigued conditions as up to 63% and 78% was explained in both conditions, respectively. However unlike Study 1, hip internal and external rotator muscles were not good predictors of knee valgus. Disagreement between the results may be related to participants being restricted to certain landing space in Study 3 whereas they were able to land freely in Study 1. However, it is clear that knee valgus during squatting can be used to estimate the quantity of knee valgus that would be experienced during landing. |
