Thigh & Knee Exercises

An effective thigh and knee exercise program does more than enhance the appearance of the legs. A balanced leg workout plan improves dynamic balance, strength and functional and athletic performance. When they include all the leg muscles, these exercise programs may play a crucial role in preventing injuries and osteoporosis.

Function

Knee specialists at the American College of Orthopaedic Surgeons explain that the knee, as the largest joint in the human body, is also the most easily injured. The knee is a hinge joint, which means that flexion and extension are its primary movements.The quadriceps, which extend the knee, and the hamstrings, which flex the knee, are the major knee-supporting muscles. The adductors, or inner thighs, move the leg toward the center of the body, and the abductors, or outer thighs, move the leg away from the body's center. The abductors and adductors act as knee stabilizers during flexion and extension movements.

Features

Physical therapists designate thigh and knee exercises as closed chain or open chain. Closed chain exercises keep the foot in a fixed position. The squat, which works the hamstrings and quadriceps, and the slide board, which works the inner and outer thigh muscles, are examples. Open chain exercises keep the foot in a free position; the leg extension machine is an example.

Considerations

Maintaining optimal inter-muscular balance is crucial to the effectiveness of a thigh and knee exercise program. Performance coach Brian Mackenzie, who created the Sport Coach website, advises that the hamstrings must be at least 80 percent as strong as the quadriceps. If your hamstrings are significantly weaker than the quadriceps, you will need to prevent muscular imbalances by devoting more of your workout to exercises for the backs of your legs.

Abductor/adductor strength ratios must also be considered. Certified trainer Eric Cressey, in an article on the Testosterone Nation website, warns that weak adductors may lead to groin strains. An article published in the "American Journal of Sports Medicine," details adductor muscle strain associated with hockey players. Lead author Timothy F. Tyler reported that a player whose adductor strength was less than 80 percent of his abductor strength was 17 times more likely to sustain an adductor strain.

Prevention/Solution

The National Osteoporosis Foundation advises people to be proactive. It recommends weight-bearing exercises to prevent the loss of bone density. Thigh and knee exercises performed in a standing position, such as squats, lunges, step-ups and slide-board training are weight-bearing activities.

Warning

While the leg extension is a common piece of thigh and knee exercise equipment, it is controversial among fitness and rehabilitation specialists. Trainer Michael P. Keenan explains that, as an open chain exercise, the leg extension creates shearing forces, which may make the knee more susceptible to injury. The leg extension also isolates the quadriceps muscle. It may exacerbate an existing muscle imbalance. The squat and leg press engage the hamstrings and gluteals along with the quadriceps. These exercises are a viable alternative.