The quadriceps femoris, more commonly referred to as the “quads,” is a group of four muscles located on the front of the thigh. The quads, along with the hamstrings (a group of muscles on the back of the thigh), are designed to work together to move and support the leg. However, many fitness enthusiasts, including amateur runners, cyclists, and gym-goers, let the quads—the larger of the two muscle groups—take charge. This means the quads get strong, but the hamstrings weaken. Aesthetically, this imbalance results in the appearance of bulky thighs. To achieve a more streamlined, dancer-like appearance, and to improve athletic performance, the hamstrings and quads must be strengthened and stretched in tandem.
The quads are a grouping of four muscles (vastus medialis, vastus intermedius, vastus lateralis, and rectus femoris) located at the front of the thigh. All four muscles start (originate) along the pelvis and end (insert) at the back of the kneecap (patella) and top of the shin bone (tibia). When you look at all the muscles that make up the quads, they resemble a feather—wide in the middle and tapered at either end.
The quads are responsible for extending the knee and flexing the hip. Extension at the knee joint means straightening the knee. When you’re standing with straight legs, the knees are in extension. Hip flexion occurs when you create a crease at the front of the hip. You can do this either by lifting the leg (like when marching) or folding the torso forward (like when bending over to tie your shoes). When seated, the hips are in flexion.
When you strengthen a muscle, for example, by lifting weights, tiny micro-tears develop in the muscle fibers. When you rest after strengthening, the body sends the necessary nutrients to repair the damage to that muscle, and to stimulate its growth to prevent future damage. It is this process of repairing the micro-tears that strengthens the muscle. Anytime you straighten the knee or flex the hips—in or out of the gym—the quads muscles are strengthened. In everyday life, the muscles are strengthened each time you walk up a flight of stairs, kick a soccer ball, or sit down into a chair. In the gym, popular strengthening exercises for the quads include squats, lunges, and straight leg raises. In all these scenarios, the knee is straightening and/or the hip is flexing.
When you stretch a muscle, some of the individual muscle fibers (long, thin muscle cells) are pulled out to their longest length, while other muscle fibers remain contracted. The more muscle fibers that lengthen, the greater the stretch. To increase the number of lengthened muscle fibers requires consistent and repetitive stretching. When all the fibers lengthen fully, the muscle is at its longest and allows for maximum flexibility at the surrounding joints. This flexibility increases your overall range of motion and decreases risk of injury. Ideally, stretching takes place after movement. Movement increases blood flow to the muscles for a safer stretch. This is often referred to as stretching “warm” muscles. The increased blood flow from movement raises the temperature in the muscle so it is literally warmer. Plus, the blood flow boosts the oxygen supply to the body and causes the muscle fibers to have greater flexibility. So, contrary to what many of us were taught, there is no need to stretch before exercise. When you stretch a “cold” muscle, the muscle fibers are less flexible. So, not only is the stretch limited, the muscle is more susceptible to injury. Stretching and strengthening have a converse relationship. For example, if the knee must be straight or the hip flexed to strengthen the quads, then the knee must be bent and the hip extended to stretch. In everyday life, you stretch the quads when standing up out of a chair, walking backwards, or coming to a high kneeling position to pose for a picture or pray. In the gym, popular stretching exercises for the quads include quads stretch and dancer pose in yoga.
Muscles support and move the skeleton, making them critically important for the structural health of your body. Muscles are made up of sheets of fibrous tissue that can contract and release. Both ends of a muscle connect to one or more bones via tendons. When a muscle contracts, the bones on either side of the muscle pull toward one another. When a muscle releases or stretches, the bones move away from each other. For example, when you’re walking, your muscles continuously contract and release to keep you moving. The body’s intricate muscle system often pairs muscles in an agonist-antagonist relationship. This means the muscles support each other by working together, so while one muscle contracts, its partner muscle stretches. In the legs, the quads and hamstrings are paired. If your dominant focus is on strengthening the quads without stretching them, then the muscles forming the hamstrings are always stretched, or strung out. Overstretched hamstrings never get the chance to strengthen. The muscles and connective tissue then become thick and tough. Tough tissues are not as flexible and are more likely to be damaged or torn when force is exerted on them (either by stretching or strengthening). Creating proportion in the stretch and strength of the quads helps balance the strength and stretch of the other muscles in the legs, most notably the hamstrings. Plus, the quads cross both the hip and knee joints. Disproportionate strength and stretch in the quads (and thus, the hamstrings as well) may result in pain and injury in the hip and knee.
Try our quads workout to strengthen, stretch, and optimize this muscle group.
The most common quads injuries include strain, tear, and inflammation. Other ailments related to imbalanced quads include, arthritis (ankle, knee, hip), ankle sprain, chondromalacia (damage to the cartilage in the knee), IT band strain, piriformis syndrome, sciatica, and low back pain.