At Rozelle Physio we treat a variety of conditions related to throwing in sport. Below are some of the factors that contribute to throwing injuries and tips on how physio can help rehabilitate a throwing injury.
There are several biomechanical reasons why throwing related shoulder injuries occur some of which include:
- alterations in throwing mechanics,
- muscle fatigue, muscle weakness or imbalance
- and excessive capsular laxity.
The most frequently observed throwing injury is posterior glenoid impingement. Also referred to as internal impingement, excessive anterior instability causes the vulnerable rotator cuff tendons to impinge against the acromion during the follow through phase of throwing. This condition can be resolved by simply stretching and strengthening the rotator cuff muscles.
Rehabilitation following a shoulder injury needs to follow a very structured, multiphase approach of:
- controlling inflammation,
- restoring muscle imbalance,
- improving soft tissue flexibility, and
- enhancing proprioception and neuromuscular control.
During the acute phase of the injury in is important not to aggravate the condition and let the pain settle before commencing any strengthening exercises. In the initial phases of rehabilitation, restoring the range of motion should come before any strengthening can be started. All the athlete’s activities need to be modified to a pain free level. Once pain free range of motion is achieved more aggressive strengthening exercises can be started. It is important to note that in an optimal shoulder the external rotators are approximately 65% in strength when compared to the internal rotators. Therefore exercises that strengthen the external rotators are the main focus for early strengthening exercises. Once significant strength has been achieved the athlete can now begin to slowly introduce a throwing program. Throwing programs are designed to slowly increase the distance the athlete is throwing taking note that the athlete should be able to throw from a distance pain free before progressing to a longer distance. Once an athlete has reached a functional distance they can return to training and athletic completion.
- Posture has much to do with mechanics at the shoulder as well. Rounded shoulder and a forward head posture are said to lead to weakness in the rotator cuff and tightness of the muscles of the anterior chest wall such as pectoralis minor.
- Even if the shoulder is asymptomatic, simply throwing does not essentially keep the muscles strengthened sufficiently. Every thrower should be complementing their training with a stretching and strengthening program for rotator cuff muscles especially.
Wind-up The wind-up may look different in every thrower but the outcome is always the same. The purpose is to set up a rhythm that synchronizes the timing of all body parts. The rhythm is set up so that all parts of the body from the legs to the arms contribute to the balls propulsion.
Early Cocking In this phase the arm is positioned from being in front of the body to behind the head in preparation of the acceleration phase. In early cocking the scapula is retracted and the humerus is abducted, externally rotated and horizontally extended. The body’s centre of gravity is lowered because the support knee and hip are flexing and the hips and pelvis begin to rotate forward.
Late Cocking In this important phase the stresses to the glenohumeral joint are at its greatest. The late cocking phase begins once the stride foot hits the ground. At this point the static stabilizers of the shoulder perform the vital role to limit further motion into external rotation. Muscles active here include the shoulder forward flexors, external rotators, subscapularis, pectoralis major and latissimus dorsi. By the end of this phase the shoulder’s internal rotators are on maximum stretch and the body is optimally “wound” for elastic energy transfer.
Acceleration This phase starts with maximal internal rotation and adduction and ends when the ball leaves the fingers. The serratus anterior and pectoralis major are strongly active as the arm moves forwards and the scapula protracts.
Follow Through Begins when the ball is released and ends when the support foot moves forward and contacts the ground. This is sometimes one of the most overlooked phases and is very important to prevent repetitive strain to the rotator cuff. The rotator cuff muscles work eccentrically to decelerate the arm and work against distraction forces at the glenohumeral joint. It is important to allow the arm to come across the body toward the opposite hip to minimize impinging forces on the rotator cuff muscles from the coracoachromil arch structures.
Houglum, P. (2011). An analysis of the biomechanics of pitching in baseball. Retrieved from http://www.humankinetics.com/excerpts/an-analysis-of-the-biomechanics-of-pitching-in-baseball
Lowe, W. Interval Throwing Program, Throwing off the Mound
Lowe, W. Thowers Ten Exercise Program
Wilk, K., Meister, K., & Andrews, J. (2002). Current concepts in the rehabilitation of the overhead throwing athlete. The American Journal of Sports Medicine, 30(1), 136-151
Wolf, B. & Wolstenholme, K. (2010). Throwing injuries: biomechanics, injury mechanisms and rehabilitation. Current Orthopaedic Practice, 21(5), 467-471