Knee effusion and quadriceps muscle strength

Area of Science:

• Biomechanics
• Exercise Physiology
• Musculoskeletal Research

Background:

• Joint swelling is common in osteoarthritis, rheumatoid arthritis, and acute trauma.
• Previous research on joint swelling has not fully simulated functional joint and muscle activity.
• Patients with knee swelling often face challenges with quadriceps exercises.

Purpose of the Study:

• To investigate the effect of induced knee effusion on quadriceps femoris concentric performance.
• To determine if moderate joint swelling impairs maximal effort isokinetic knee extension.
• To assess the influence of pre-exercise activity on performance with knee effusion.

Main Methods:

• Ten healthy subjects performed maximal effort isokinetic knee extension at two velocities.
• Knee effusions of 0-90 ml were induced using saline and dextrose solution.
• Protocols included/excluded local anesthetic and submaximal exercise prior to testing.

Main Results:

• Quadriceps peak torque and power were unaffected by effusion amount when preceded by submaximal exercise.
• Peak torques significantly decreased during isokinetic actions without prior submaximal work.
• Findings suggest moderate swelling may not impair performance under specific exercise conditions.

Conclusions:

• Moderate knee effusion does not necessarily impair quadriceps performance during functional activities.
• Submaximal exercise prior to maximal effort may mitigate the effects of joint swelling.
• Patients with knee swelling can be encouraged to engage in active muscle work if other symptoms permit.