In knee OA , strong evidence was found that avoidance of activities is associated with activity limitations via muscle weakness ( mediation by muscle weakness ) , strong evidence was found for an association between muscle weakness and activity limitations , and weak evidence was found that pain and psychological distress are associated with muscle weakness via avoidance of activities ( mediation by avoidance ) .
In hip OA , weak evidence was found for mediation by muscle weakness ; and strong evidence was found for an association between muscle weakness and activity limitations .
The avoidance model in patients with knee and hip osteoarthritis ( OA ) hypothesizes that pain and psychological distress lead to avoidance of activities , and thereby to muscle weakness and activity limitations .
This paper systematic ally review s the scientific evidence for the validity of this avoidance model .
Nonsteroidal anti-inflammatory drug or glucosamine reduced pain and improved muscle strength with resistance training in a randomized controlled trial of knee osteoarthritis patients.
OBJECTIVES To investigate the effect of 12 weeks of strength training in combination with a nonsteroidal anti-inflammatory drug ( NSAID ) , glucosamine , or placebo on muscle cross-sectional area ( CSA ) , strength ( primary outcome parameters ) , and function , power , pain , and satellite cell number ( secondary outcome parameters ) in patients with knee osteoarthritis ( OA ) . DESIGN Double-blinded , r and omized controlled trial . SETTING Hospital . PARTICIPANTS Patients ( N=36 ; 20 women , 16 men ; age range , 50 - 70y ) with bilateral tibiofemoral knee OA . A total of 181 patients were approached , and 145 were excluded . INTERVENTIONS Patients were r and omly assigned to treatment with the NSAID ibuprofen ( n=12 ) , glucosamine ( n=12 ) , or placebo ( n=12 ) during 12 weeks of quadriceps muscle strength training . MAIN OUTCOME MEASURES Muscle CSA and strength . RESULTS No differences between groups were observed in gains in muscle CSA . Training combined with ibuprofen increased maximal isometric strength by an additional .22Nm/kg ( 95 % confidence interval [ CI ] , .01-.42 ; P=.04 ) , maximal eccentric muscle strength by .38Nm/kg ( 95 % CI , .05-.70 ; P=.02 ) , and eccentric muscle work by .27J/kg ( 95 % CI , .01-.53 ; P=.04 ) in comparison with placebo . Training combined with glucosamine increased maximal concentric muscle work by an additional .24J/kg versus placebo ( 95 % CI , .06-.42 ; P=.01 ) . CONCLUSIONS In patients with knee OA , NSAID or glucosamine administration during a 12-week strength-training program did not improve muscle mass gain , but improved maximal muscle strength gain in comparison with treatment with placebo . However , we do not find that the benefits are large enough to justify taking NSAIDs or glucosamine
In knee OA , strong evidence was found that avoidance of activities is associated with activity limitations via muscle weakness ( mediation by muscle weakness ) , strong evidence was found for an association between muscle weakness and activity limitations , and weak evidence was found that pain and psychological distress are associated with muscle weakness via avoidance of activities ( mediation by avoidance ) .
In hip OA , weak evidence was found for mediation by muscle weakness ; and strong evidence was found for an association between muscle weakness and activity limitations .
The avoidance model in patients with knee and hip osteoarthritis ( OA ) hypothesizes that pain and psychological distress lead to avoidance of activities , and thereby to muscle weakness and activity limitations .
This paper systematic ally review s the scientific evidence for the validity of this avoidance model .