The quadriceps femoris, also called the quadriceps or simply quads, is a large muscle group that consists of four muscles located on the front of the thigh. (Quadriceps is used both in the singular and plural sense.) The four muscles of the quads are the rectus femoris, vastus medialis, vastus intermedius, and vastus lateralis. As the strongest muscle in the human body, it is important to exercise the quadriceps on a regular basis to maintain a healthy and fit body.
The quadriceps, all four of the muscles, are used as extensor muscles for the knee joint. They are necessary for humans to be able to walk, run, jump, squat, and perform other such actions. In addition, the rectus femoris, one of the four muscles, is used as a flexor of the hip because it is attached to the ilium (the uppermost, and largest, bone of the pelvis). The vastus medialis, another quad muscle, also helps to stabilize the patella (kneecap) and the knee joint during the gait process.
The quadriceps absorb much of the stress that is placed on the knees while doing such activities as walking, jumping, and running. They are also responsible for straightening the knees and stabilizing the kneecaps. Exercise of the quadriceps is very important for overall physical health and is crucial for good health of the knees.
Whether young or old, physically fit or not, the regular exercising of the quads is very important for maintaining (or re-gaining) a healthy body. To keep the body in shape, the quadriceps should be strong so the lower body, especially the knees, can move the upper body around in its daily activities. Such exercises are especially important when performing athletic competitions and physical fitness events such as playing football, baseball, basketball, tennis, ice and field hockey, soccer, and bowling, and performing such activities as riding a bicycle, mowing the grass, climbing the stairs, hiking in a forest, and skiing down a hill.
The quadriceps is the extensor muscle for the knee. Located on the front and sides of the femur, these four muscles—rectus femoris, vastus medialis (internus), vastus intermedius, and vastus lateralis (externus)—are located on the front of the thigh and attached to the kneecap through the quadriceps tendon.
The rectus femoris is positioned on the middle of the thigh. Originating at the ilium (the largest and uppermost bone of the pelvis), the rectus femoris covers a majority of the other three muscles of the quads. Also beginning at the femur, the rectus femoris covers the area from the trochanters (part of the thighbone) to the condyles (the round prominence at the end of the femur). The vastus lateralis is on the lateral side of the femur (outer side of the thigh), while the vastus medialis is on the medial side of the femur (inner side of the thigh). The vastus intermedius—located between the vastus lateralis and the vastus medialis—is on the front of the femur (top of the thigh).
Common exercises that benefit the quadriceps include:
These and similar exercises are important to keep the quadriceps in good shape. Weak quad muscles can lead to knee-related injuries and, worst of all, loss of leg mobility due to a breakdown of the quadriceps mucles.
The quadriceps should be stretched before and after exercising. Stretching these muscles keeps them long and flexible, allowing them to work more efficiently. Quadriceps that are well exercised are less at risk to be injured. When stretching the quadriceps, hold a stretch for about 30 seconds. Remain stationary—do not introduce any bouncing motions into the stretching exercise because such action can lead to damage of these muscles.
There are various stretching exercises for the quadriceps. One of them is the standing quadriceps stretch. With both feet positioned side-by-side, raise the left foot toward the buttocks, so the thigh is about parallel to the floor. When the muscle begins to stretch, a burning sensation is felt at the front of the thigh. Hold this stretch for about 30 seconds and then lower the leg back to its original position. Repeat the stretch with the other leg.
Another quadriceps exercise is one performed lying down. While lying on the floor on the stomach, hold the right ankle and pull it toward the buttocks. Continue the motion until the quads begin to burn. Hold the position for about 30 seconds. Then, lower the leg. Repeat with the left leg.
Various quadriceps injuries can occur, especially in activities involving jumping, kicking, or sprinting. The rectus femoris is frequently at the center of the injury because it crosses both the hip joint and knee joint—the only quad muscle so positioned. Located at these two critical positions, the rectus femoris is more susceptible to injury. A common site of injury is at or around the musculotendinous junction, the location where the muscle meets the tendon just above the knee.
All of the quad muscles can be injured due to being compressed against the femur bone (what is called a compression injury). This type of injury is usually quite painful and can be temporarily disabling if serious enough. However, it rarely becomes a permanent disability. Other injuries to the quadriceps range from simple strains to more disabling muscle ruptures. The most common injury to the quads is a contusion. It is frequently caused by a direct impact to the anterior thigh from an object, such as another person's helmet while playing football.
Injuries while exercising the quadriceps is also possible. A common injury during exercise is what is called jumper's knee (patellar tendinopathy), a strain at a muscle of the quadriceps that occurs at the conjoined muscle tendon junction. Risks from quadriceps exercises can be minimized by first seeking medical advice from a trusted medical professional. Make sure the body is ready for quad exercises by gradually building up an exercise routine. If the exercise feels comfortable for the quad muscles, then it is appropriate for one's level. Never do too much and risk injuring the muscles. Never perform exercises if pain is present. Mild discomfort is natural when doing exercises, especially then the muscle is being stretched.
To avoid injuries and to minimize the chance of more serious injuries when they occur:
Health benefits are obtained when performing a moderate amount of physical exercise daily, such as exercises for the quads. Regular physical activity plays a beneficial role in preventing disease and improving overall health status. Specifically, strong quadriceps are essential for good performance in any athletic endeavour or physical activity. Well-toned and developed quads provide the necessary power to swim the length of a pool, run up and down a basketball court, or run a marathon race. Strong quads are also important for living an independent and healthy life.
See also Leg exercises .
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William A. Atkins, BB, BS, MBA