Eccentric Muscle Strengthening Using Maximal Contractions Is Deleterious in Knee Osteoarthritis: A Randomized...

Area of Science:

• Orthopedics
• Sports Medicine
• Rehabilitation

Background:

• Knee osteoarthritis (OA) is a degenerative joint disease characterized by pain and functional decline.
• Quadriceps strength is crucial for knee function and mobility in OA patients.
• Eccentric and concentric muscle strengthening are common rehabilitation strategies.

Purpose of the Study:

• To compare the efficacy of eccentric versus concentric isokinetic muscle strengthening in improving quadriceps strength in individuals with knee OA.
• To assess the safety and adverse event profiles of both training modalities.

Main Methods:

• A randomized controlled study involving 12 sessions of isokinetic strengthening over 6 weeks.
• Participants aged 40-70 with predominantly unilateral femorotibial OA were recruited.
• Primary outcome: change in concentric isokinetic knee extension peak torque; Secondary outcomes: hamstring strength, walking speed, pain, and functional status (WOMAC).

Main Results:

• Concentric strengthening led to greater improvements in quadriceps strength compared to eccentric training, though not statistically significant.
• The eccentric training group experienced a 25% rate of major adverse events.
• No significant differences were observed in secondary outcomes between groups at 6 weeks or 6 months.

Conclusions:

• Concentric training appears more effective than eccentric training for enhancing quadriceps strength in knee OA.
• Eccentric training is associated with a higher risk of muscle injury, especially hamstring injuries.
• Further research is needed to optimize eccentric training protocols for OA rehabilitation.