Injury Definitions

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Before you can understand your injury, you have to know what you can injure. Consider this STACK Athlete Anatomy 101: An overview of what your body uses to walk, run, jump and catch. 

Body Composition
Bones, muscles, tendons, ligaments and joints all work together to create and transfer the energy needed for your body to move in any way.

  • Bones are hard, dense connective tissue that give your body structure and support. An adult human body has more than 200 bones.
  • Muscle is tissue composed of fibers capable of contracting to effect bodily movement. There are three types:
    • Cardiac muscles—your heart, which pumps blood and oxygen to your entire body.
    • Involuntary muscles—those you cannot control, including your blood vessels, skin, stomach, and intestines.
    • Voluntary muscles—those responsible for moving your body, allowing you to walk, talk, run, kick, etc. Your brain controls these muscles by telling them when to fire and how fast or slow to do so.
  • Tendons are bands of tough, inelastic tissue that connect your muscles to your bones. For example, your Achilles tendon connects your calf muscle to your heel bone. When a muscle contracts, it pulls on the bone; the tendon is what transmits the force of the muscle to the bone, enabling you to move.
  • Ligaments are bands of tissue that connect bone to bone and stabilize joints. For example, your anterior cruciate ligament [ACL] holds together your femur and tibia bones.
  • Joints are the point of connection between two bones. They allow movement and provide structure to the body. Your shoulders, knees, hips, ankles and wrists are all joints.

Common Injuries

  • Bone Injuries
    • A fracture is when the bone breaks. An open fracture is when the broken end of a bone punctures your skin.
    • A dislocation is when a bone dislocates from its joint. When dislocation happens, the ligaments that hold the bone in place are torn; therefore the joint no longer works.
  • Ligament and Muscle Injuries
    • A sprain is sudden overstretching of a ligament. There are four stages of a sprain:
      • Stage 1: a minor stretch or tear;
      • Stage 2: a complete ligament tear;
      • Stage 3: when the ligament ruptures;
      • Stage 4: when small bones around the ligament break.
    • A pulled muscle, or a strain—much less severe than a sprain—is a muscle injury caused by overstretching. Most strains can be treated with rest, ice, compression and elevation.
  • Tendon Injuries
    • Tendonitis, caused by overuse and the stress of repeated motion, is inflammation and irritation of the tendon, which makes functioning of the tendon painful.
    • A rupture is when the tendon snaps because of the force of pressure applied to it. Though uncommon, ruptures can cause permanent disability. The four tendons most susceptible to rupture are your Achilles, Quadricep, Bicep and Rotator Cuff.
  • Joint Injuries

The most common joint injury for athletes is pain from overuse of and stress on the joints. Catcher's Knee and Tennis Elbow are examples of overuse injuries in joints. Too much joint stress can lead to arthritis.


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