Knee sprains can occur during sports activities or may result from trauma, such as a fall. Sprains affect the ligaments that hold your bones together. The cartilage that provides padding between the bones in your knee is also sometimes injured.

Muscle strains cause tiny tears in your muscle fibers. These injuries typically occur when a muscle is overstretched.

The gluteus medius is an important muscle located in the buttocks that plays a crucial role in the stability as well as leveling of the hips. As a stabilizing muscle, the gluteus medius helps an individual maintain balance during hip abduction as well as internal and external rotation of the hip.

Magnesium is a mineral crucial to the proper function of your muscles, kidneys and heart. It is the fourth most abundant mineral in your body, according to the Office of Dietary Supplements. Only 1 percent of your bodily magnesium is in your bloodstream, while a majority is stored in your cells and bones.

Your deltoid is the large layer of muscle that covers your shoulder. The deltoid is the first layer of muscle underneath your skin and helps you lift your arm over your head. Deltoid injuries include strains and tears of the muscle.

A strain takes place when muscle fibers get overstretched and slightly torn. This injury is less severe than a pull, which causes larger tears in the muscle. Pain and tightness in the affected muscle are the most common symptoms of a strain.

A pulled muscle in the back commonly affects the quadratus lumborum. This large, triangular-shaped back muscle is responsible for movement of the spinal column, so muscle strain here results in obvious symptoms that restrict mobility.

The pubococcygeus muscle, generally referred to as the PC muscle, is pivotal to genital functioning in both sexes. This muscle runs from the pubic bone to the tail bone, also known as the coccyx. The failure of this vital muscle to relax as necessary can cause significant problems--often in multiple body areas.

When you refer to the muscles of your thigh, you are not simply referring to one muscle. Your thigh is actually made up of three muscles: hamstrings in the back, adductor muscles along the insides and quadriceps (the large muscle in the front).

The sternocleidomastoid, or SCM, muscle originates on the breastbone and attaches to the collarbone and the temporal bone on the back of the skull. You have one SCM on each side of your neck. These muscles tilt and rotate your head to the right and left. Sudden movements, such as whiplash, can cause SCM injury.

The biceps muscle is on the front part of the upper arm. The muscle is attached to the elbow and at two places in the shoulder. Inflammation of the long tendon, which runs over the top of the upper arm and attaches to the top of the shoulder blade, is fairly common for athletes.

Hip abductor and flexor strains occur when the muscle or tendon of the hip is stretched or torn due to overuse during exercise or sports. Often these injuries require several weeks of rest, therapy and medications to ensure the strain has been completely healed before returning to physical activity.