Related Experiment Video
Updated: May 27, 2026

Muscle Imbalances: Testing and Training Functional Eccentric Hamstring Strength in Athletic Populations
Published on: May 1, 2018
Passive knee-extension test to measure hamstring tightness: influence of gravity correction
Kenny Guex1, Francois Fourchet, Heiko Loepelt
1HECVSanté Dept of Physiotherapy, University of Applied Sciences of Western Switzerland, Lausanne, Switzerland.
Context:
A passive knee-extension test has been shown to be a reliable method of assessing hamstring tightness, but this method does not take into account the potential effect of gravity on the tested leg.
Objective:
To compare an original passive knee-extension test with 2 adapted methods including gravity's effect on the lower leg.
Design:
Repeated measures.
Setting:
Laboratory.
Participants:
20 young track and field athletes (16.6 ± 1.6 y, 177.6 ± 9.2 cm, 75.9 ± 24.8 kg).
Intervention:
Each subject was tested in a randomized order with 3 different methods: In the original one (M1), passive knee angle was measured with a standard force of 68.7 N (7 kg) applied proximal to the lateral malleolus. The second (M2) and third (M3) methods took into account the relative lower-leg weight (measured respectively by handheld dynamometer and anthropometrical table) to individualize the force applied to assess passive knee angle.
Main Outcome Measures:
Passive knee angles measured with video-analysis software.
Results:
No difference in mean individualized applied force was found between M2 and M3, so the authors assessed passive knee angle only with M2. The mean knee angle was different between M1 and M2 (68.8 ± 12.4 vs 73.1 ± 10.6, P < .001). Knee angles in M1 and M2 were correlated (r = .93, P < .001).
Conclusions:
Differences in knee angle were found between the original passive knee-extension test and a method with gravity correction. M2 is an improved version of the original method (M1) since it minimizes the effect of gravity. Therefore, we recommend using it rather than M1.

