Knee extensor torque of men with early degrees of osteoarthritis is associated with pain, stiffness and function.
BACKGROUND
Osteoarthritis (OA) is a chronic-degenerative disease. The knee is the most commonly affected joint and the symptoms are generally attributed to quadriceps muscle weakness. However, few studies have evaluated this relationship in a population with early stages of knee OA.


OBJECTIVE
To investigate whether a correlation among the knee extensor torque and the three subscales of the WOMAC questionnaire in men with early stages of knee OA exists.


METHODS
Twenty-one men with knee OA grades I or II (according to Kellgren and Lawrence criteria) participated in this study. The concentric and eccentric knee extensor torque were assessed using a Biodex System 3 Pro® isokinetic dynamometer, at a speed of 90º/s. Self-reported symptoms and disability were assessed using the WOMAC questionnaire. Spearman's correlation coefficient was used to test the relationship between the dependent variables (three subscales of WOMAC questionnaire) and the independent variables (average knee extensor peak torque).


RESULTS
We found a strong negative correlation between the concentric extensor torque and pain (r=-0.7, p<0.001) and a moderate and negative correlation among the concentric extensor torque and stiffness (r=-0.62, p=0.002) and physical function (r=-0.54, p=0.011). Eccentric extensor torque presented a moderate and negative correlation with the three subscales of the WOMAC (r=-0.40 to 0.69, p<0.05).


CONCLUSIONS
The concentric and eccentric knee extensor torque is significantly correlated with self-report symptoms of patients in initial stages of knee OA. Therefore, the strengthening of the quadriceps muscles, through concentric and eccentric exercise is indicated for these patients in order to minimize these symptoms.
Physical Therapy Department, Universidade Federal de São Carlos, São Carlos, SP, Brazil.
Paula R M S
PR
Serrão
Karina
K
Gramani-Say
Giovanna C
GC
Lessi
Stela M
SM
Mattiello
D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000150:complications / Q000503:physiopathology*; D010146:Pain / Q000209:etiology / Q000503:physiopathology*; D016059:Range of Motion, Articular