Body symmetry is a very important objective measurement which physical therapists examine throughout the rehabilitation progress. 

Why is symmetry so important? Because poor balance of such things as muscle tightness, stretch, bone length, pelvic rotation, and scapular positioning leads to increased risk of injury and decreased performance. 

While the human body is not completely equal side to side, relatively speaking, there are general norms.  Here are 5 common asymmetries in young athletes that physicians, physical therapists, and athletic trainers look for.

Shoulder rotation

Abnormal bilateral shoulder range of motion is common among throwing athletes, such as baseball and softball pitchers. The shoulder capsule on the throwing side will generally tighten in the back (posterior) and loosen in the front (anterior) causing a relative increase in shoulder rotation backward (external rotation) and decreased forward movement (internal rotation). Offsetting this relationship may have impact on underlying structures, including the rotator cuff and labrum.

Scapular positioning

Weakness or tightness in particular muscles cause the shoulder blade (scapula) to wing outward, leaving it relatively farther away from the center. In addition, tightness in the neck muscles may elevate the shoulder, causing imbalance from side to side.  A poorly positioned scapula puts increased strain on neck muscles, decreases strength with pushing and pulling, and leads to poor posture, which irritates the spine.

Hip alignment

Hip alignment is pivotal to reducing lower back, hip, knee, and ankle injuries. The interaction between the lower back and pelvis act as the "foundation" for the human skeletal system.   All forces from walking, running, jumping, etc. are exchanged bet

ween the hips and lower back. Hips that are rotated forward, backward, or tilted to one side set up a series of orthopedic problems and increase injury risk.

Arch height

Excessively high arches or flat feet are generally a concern for athletic movements. Unless there is pain or injury, though, there generally is no need to address this particular aspect of body symmetry.   A physical therapist examines the feet to determine if the arches are within norms. The presence of one very flat foot and one very high arch may indicate problems elsewhere and cause for further analysis.

Mid-back rotation 

Increased rotation to one side versus the other is common with swinging sports, such as baseball and golf, but relative balance is still critical for sports performance and injury prevention. Muscles and ligaments along the rib cage and spine will change with repetitive motion, but it is still important to maintain balance. Over rotation to one side can increase risk of dislocated ribs, strained muscles, and bony changes to spinal vertebrae.

Advice to parents: get help

If something looks funny or out of whack, let the physician or physical therapist figure it out!  If you can see that one of your child's shoulder blades is winging out or that one hip is elevated, which is causing them to walk with a limp, have them checked out by a health care professional. This area of physical therapy requires a great deal of expertise, experience, and meticulous measurements at times.  PTs spend years studying and learning orthopedic norms, so if something is out of balance, it is easy for them to spot. Maintaining good body symmetry ensures your young athlete is utilizing all of their muscles and joints to their maximum potential while keeping the risk of injury to a minimum.

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