The quadriceps are a group of four muscles -- the rectus femoris, vastus intermedius, vastus lateralis and vastus medialis -- that attach to the patellar tendon of the knee, which attaches to the tibia bone of the lower leg. Quadriceps tendinitis refers to inflammation of this tendon, which causes localized pain and swelling. Along with other interventions, performing knee extension exercises to strengthen the patellar tendon and the quadriceps muscles may help treat the symptoms and prevent the condition from recurring.
Dumbbell Step-Up
The dumbbell step-up exercise requires two equally-weighted dumbbells and a sturdy box or a step, at least 6 inches high. You may choose not to use dumbbells at first if doing so increases your pain. Stand upright with your feet about hip-width apart and toes 12 inches behind the box. Hold the weights outside your hips with your palms facing inward. Step on top of the box with your right foot and then extend your right knee, lifting your left foot off the floor. Step back down with your left foot, followed by your right, and then step up with your left foot. Continue alternating legs for 16 to 30 total repetitions, depending on the weight of the dumbbells. Discontinue the exercise immediately if you feel increased pain.
Leg Extensions
Leg extensions are performed on a machine with a chair and a padded foot bar, which is attached to a stack of weights with a cord through a pulley system. Sit on the chair with your back flush against the back rest. Hold under the sides of the seat with both hands to keep your upper body from moving during the exercise -- some machines have handles on each side for this purpose. Place the top of your feet under the foot bar and extend your legs straight to lift it upward. Slowly return to the start position and repeat. You can also perform leg extensions from home using a chair and ankle weights.
Single-Leg Squat
The single-leg squat is a variation of the classic exercise that uses your body weight to isolate one leg at a time. Stand upright with your left foot slightly in front of your right and hands by your sides. Lean forward so your head is over your left foot and then flex your left knee to lower your body. Allow your right heel to come up, but keep your toes on the floor. Stop before your left thigh is parallel to the floor, stand back up and repeat. Perform the exercise with your right foot forward as well. Hold your back foot off the floor or hold dumbbells in your hands to make the exercise more challenging.
References
- "Basic Biomechanics"; Susan J. Hall; 2007
- MayoClinic.com: Tendinitis
- American Council on Exercise: Dumbbell Step-Up
- "Essentials of Strength Training and Conditioning"; Thomas R. Baechle and Roger W. Earle; 2000
- American Council on Exercise: Single-Leg Squat
