What are the recommended exercises for quadriceps strengthening?

Recommended Quadriceps Strengthening Exercises

Start with isometric quadriceps exercises (static quadriceps contractions and straight leg raises) as your foundation, then progress to closed kinetic chain exercises (leg press, squats), and finally incorporate open kinetic chain exercises and eccentric training for maximum strength gains. 1, 2

Initial Phase: Isometric Exercises (Weeks 0-2)

• Begin with static quadriceps contractions (quad sets) and straight leg raises, which can be safely prescribed from day one and provide faster recovery of knee range of motion without compromising stability 1, 2
• Perform these exercises 4 times daily during the initial rehabilitation period 2
• Isometric quadriceps exercises demonstrate significantly greater vastus medialis muscle activation compared to straight leg raises, making quad sets particularly effective for targeted quadriceps strengthening 3
• These exercises are proven to improve muscle strength, reduce pain intensity, and enhance function when performed 5 days per week for 5 weeks 4

Progressive Loading: Closed Kinetic Chain Exercises (Weeks 2-4+)

• Introduce leg press exercises starting at week 3, which improves subjective knee function and functional outcomes 1
• Progress to squat variations and other closed kinetic chain exercises if the knee does not react with swelling or increased pain 2
• Closed kinetic chain exercises produce less anterior knee pain compared to open kinetic chain exercises, making them safer for early-phase strengthening 1, 2
• Use an initial intensity of 50-60% of one-repetition maximum (1-RM) for lower body exercises 1
• Perform 10-15 repetitions per set, completing 1-2 sets, 2-3 days per week 1

Advanced Strengthening: Open Kinetic Chain Exercises (Week 4+)

• Introduce open kinetic chain exercises (knee extensions) from week 4 onwards, starting in a limited range of motion (90°-45°) 1, 2
• Progress the range of motion gradually:
  • Week 5: 90°-30° 2
  • Week 6: 90°-20° 2
  • Week 7: 90°-10° 2
  • Week 8: Full ROM 2
• Both open and closed kinetic chain exercises are recommended for regaining quadriceps strength, with no significant differences in anterior tibial laxity, subjective knee function, or functional activities between the two 1
• Monitor for anterior knee pain, which occurs more frequently with open kinetic chain exercises 1, 2

Eccentric Training for Maximum Gains (Week 3+)

• Incorporate eccentric cycle ergometer training starting at week 3 for greater strength gains, better daily activity levels, and greater quadriceps muscle hypertrophy, with beneficial effects persisting 1 year after initiation 1
• Eccentric training improves functional outcomes and psychological readiness to return to sport 1
• Combining eccentric and plyometric exercises is more effective than either modality alone for improving balance, functional activities, subjective knee function, and psychological readiness 1
• Both concentric and eccentric training improve quadriceps strength without significant differences between groups, though eccentric overload training does not enhance strength gains beyond standard eccentric training 1

Isokinetic Training Option (Week 3+)

• Start isokinetic hamstring and quadriceps strengthening at week 3 using a functional pattern similar to a half squat (0°-45°) to improve both quadriceps and hamstring strength, functional activities, and subjective function 1
• Monitor for anterior knee pain and progress load accordingly 1

Exercise Prescription Parameters

• Perform exercises through a full range of motion at a moderate to slow controlled speed 1
• Exhale during the contraction phase and inhale during the relaxation phase to avoid Valsalva maneuver 1
• Alternate between upper and lower body work to allow adequate rest between exercises 1
• A comprehensive program of 8-10 exercises involving major muscle groups (including quadriceps extension or leg press) can be accomplished in 15-20 minutes 1
• Single-set programs performed a minimum of 2 days per week are highly effective and promote adherence during initial training 1

Critical Pitfalls to Avoid

• Do not perform aggressive stretching or loading in the acute phase, as this can worsen injury 2
• Avoid relying solely on passive therapy (massage, ultrasound, heat); active interventions show superior results 2
• Do not introduce open kinetic chain exercises before week 4, as there is no evidence supporting earlier introduction and hamstring grafts may be more vulnerable to early open kinetic chain exercises 1
• Be cautious with open kinetic chain exercises as they induce more anterior knee pain compared to closed kinetic chain exercises 1, 2

Evidence for Effectiveness

• An 8-week quadriceps strengthening program significantly improves pain, function, and quality of life in patients with knee osteoarthritis 5
• Effective exercises include straight leg raises, terminal knee extensions, and open/closed chain movements performed over 8-12 weeks 6
• Quadriceps strengthening is superior to proprioceptive training alone, though combination with Russian electrical stimulation shows additional benefits 7