The assessment of knee joint position sense as a predictor of injuries/reinjuries

B Stillman*, ] McMeeken, R Macdonell & K Bennell School of Physiotherapy, The University of Melbourne, Melbourne

Objective: To compare knee joint position sense (JPS) in (1) elite Australian Rules footballers (ARFs) and non-athletic control subjects, and (2) elite ARFs with and without ligament-injured knees.

Method: JPS was tested by actively positioning the knee, followed by a matching response using the same joint. Reflective markers attached to the side of the limb facilitated computer calculation of the joint angles from videotape obtained during the procedure. Active JPS was examined in three positions in:

(1) 43 ARFs and 16 age-matched control subjects (2) 51 ARFs and 12 ligament-injured knees in 9 ARFs.

Results: There was no significant difference between the elite ARFs:

(1) and control subjects with respect to the absolute errors (3.7 -+ 2.1 ° and 2.9 + 1.5 ° respectively) or variable errors (2.3 + 2.2 ° and 2.3 + 1.9 ° respectively).

(2) with and without ligament-injured knees {5.0 + 2.2 ° and 5.0 ± 2.6 ° respectively) or variable error (3.2 + 1.7 ° and 3.2 + 2.0 ° respectively).

Conclusions and significance: (1) The proposition that elite sportspersons have superior proprioception may not be

valid. (2) When tested actively, JPS in ligament-injured knees may not be significantly deficient.

The relationship between joint sense and sports injuries has rarely been investigated, and the methods of testing have usually been passive. Since sport involves active postures and movement , it is argued that JPS testing should be active. Problems of accuracy and reliability in previous studies have been here addressed by using computer-aided analysis of videotaped tests and responses. The retention of substantial JPS in ligament-injured knees may be because normal position sense is largely mediated by muscle receptors, or because muscle receptors compensate for lost joint receptor activity. Although normal JPS does not guarantee injury-free sport, it remains unclear as to what if any level of JPS provides some measure of protection against injury, or what level of specific proprioceptive training and rehabilitation is justified. The procedures used in the present study provide the opportunity to further investigate these and related questions.

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