Preventing Arm Injuries in Overhead Athletes, Part II

Part I of Preventing Arm Injuries in Overhead Athletes introduced the biomechanical implications of overhead motions and the injuries common to such movement, and suggested flexibility testing, stretching and warm-up exercises coaches and trainers can use to help mitigate the risk of injury. Part II of this article focuses on how coaches can determine which muscles are weak in an athlete’s shoulders and focus training programs to strengthen them to better withstand the repetitive stresses of competition.

Identifying Muscle Imbalance

Among the many different shoulder complaints experienced by overhead athletes, shoulder impingement is one of the most common (Page, 2011). Impingement occurs when attempting to raise the arm overhead and the humeral head gravitates upwardly and pinches the supraspinatus tendon, resulting in pain and an inability to raise the arm. Neurologist Vladimir Janda has suggested that shoulder impingement is a common finding in many patients resulting from muscle imbalances, including weakness of the lower and middle trapezius, serratus anterior, infraspinatus, and deltoid, coupled with tightness of the upper trapezius, pectorals and levator scapula (Page, 2011). The serratus anterior is also one of the primary muscles responsible for maintaining normal rhythm and shoulder motion, and lack of strength or endurance can cause scapular winging (when the shoulder blade protrudes away from the ribs and looks like a “wing”). Fatigue in the serratus anterior causes alterations in the normal positioning of the scapula and as a result the position of the humeral head is impacted, possibly leading to rotator cuff impingement and/or tears (Decker, Hintermeister, Faber & Hawkins, 1999). Of the four muscles that compose the rotator cuff group, the supraspinatus is the most often injured because it gets impinged when the scapula is not sufficiently stabilized. Another common muscle imbalance to result from overhead motion is an increase in the strength of the internal rotators coupled with a decrease in the strength-ratio of the external rotators (infraspinatus, teres minor, posterior deltoid) (Saccol et al., 2010).

There are a number of assessments that the fitness professional can perform on athletes to determine if there is impingement or weakness in specific muscles (Kendall, McCreary, Provance, Rodgers, & Romani, 2005).

Recommended Impingement / Manual Strength Tests

Shoulder Impingement

Instruct the athlete to place their hand on their opposite shoulder, then lift their elbow as high as they can toward the sky. This position places the posterior shoulder on stretch. Pain in the front of the shoulder may indicate impingement syndrome, pain on the top of the shoulder my indicate AC joint dysfunction, and pain in the posterior shoulder may indicate posterior capsule dysfunction (Clark & Russell, 2007).

Serratus Anterior

Have the athlete stand with the hands against a wall at shoulder height and the elbows extended. Instruct them to push hard against the wall, displacing their thorax backward.

Normal	Weakness (left-scapular winging )

Trapezius & Rhomboids

1. With the athlete lying prone on a table, position the shoulder in 90° of abduction, and externally rotated (thumb pointing upward) with the scapula adducted and upwardly rotated.
2. Keep the shoulder in the same 90° of abduction, but internally rotated (thumb pointing down) and the scapula adducted and downwardly rotated. Apply downward pressure on the distal forearm. Weakness results in abduction of the scapula and a forward position of the shoulder.
3. Position the shoulder in approximately 135° of abduction, externally rotated with the scapula adducted and depressed. Apply downward pressure on the distal forearm. Weakness allows the scapula to ride upward and tilt forward.

1. Trapezius-Middle fibers	2. Rhomboids	3. Trapezius-Lower fibers

Based on the findings from the impingement/manual strength tests, the fitness professional can apply the exercises listed in the sample exercises for the specific weaknesses noted.

Sample Exercises

A properly designed training program must incorporate all of the muscles responsible for the overhead motion, including exercises for the scapula stabilizers and rotator cuff that increase shoulder girth and endurance (Gross, 1994). Exercises should resemble the sport-specific arm motions, integrating the shoulder exercises into a functional kinetic chain. Many experts advocate mimicking the overhead motion with diagonal pattern exercises that simultaneously synchronize trunk and lower limb stabilization (Cools, et al., 2007). If there is weaknesses in the lower body (for example, the plant leg of a pitcher), the shoulder muscles must compensate and provide even more deceleration than necessary to slow the arm down. Therefore it is important to incorporate shoulder-specific exercises with the entire body and force it to stabilize as it typically would in competition to help prevent muscle imbalances elsewhere. This kind of functional training will not only help decrease the risk of injury, but also improve performance.  Simply implementing a four-week program of light dumbbell and tubing exercises resulted in a 6% increase in maximal serve speeds in collegiate tennis players (Treiber, Lott, Duncan, Slavens, & Davis, 1999).

Training Contraindications

Specific exercises would not be advised when it comes to training for a healthy shoulder. Behind-thehead exercises like pull-ups, lat pulldowns, or military presses, place the rotator cuff in a position which causes impingement. Any kind of overhead pushing or pulling exercise should be done with the shoulders in the "scapular plane" rather than the true frontal plane. The scapular plane is approximately 30 ° anterior to the frontal plane. Modifications to overhead pushing and pulling exercises should be made to always keep the weight in front of the head bringing the weight down towards the chin, rather than behind the neck.

Each exercise described below targets a specific group of muscles, but also requires the entire body to work as an integrated functional unit, so in reality many muscles are being trained. It is important to remember that the weight must not exceed an amount that impairs form or technique, as we are trying to prevent overtraining, not cause it. Training guidelines are taken from the National Academy of Sports Medicine’s OPT (Optimum Performance Training) Pyramid approach to functional training, starting with stabilization at the bottom, progressing up to strength, and finally into power (Clark & Russell, 2002).

LOWER/MID TRAPEZIUS & RHOMBOID FOCUS

• Ball Combo (Y, T, Cobra)
  1. Start with ball between waist and belly button.
  2. Keep body in a straight line making approx. 30º angle.
  3. Holding light weight, extend arms down with thumbs pointing forward.
  4. Raise arms up at a 45º angle to parallel with the ground. Hold 2 seconds.
  5. Rotate arms to be in line with shoulders. Palms down. Hold 2 seconds.
  6. Extend shoulders back while pinching shoulder blades and externally rotating shoulder so thumbs face up. Hold 2 seconds. 
  7. Return to starting position.

• Ball 2-Arm DB Horizontal Row
  1. Start with ball between waist and belly button.
  2. Keep body in a straight line making approximaely a 30º angle.
  3. Holding moderately heavy weight, extend arms down with thumbs pointing inward. Raise arms up with elbows bent at 90º making sure elbows do not go past torso.

• Ball Horizontal Abduction w/ External Rotation
  1. Start with ball between waist and belly button.
  2. Keep body in a straight line making approximately a 30º angle.
  3. Holding light weight, extend arms down so thumbs are out. 
  4. Raise arms so they are parallel with ground with thumbs pointing towards sky.

• Ball Cobras
  1. Start with ball between waist and belly button.
  2. Keep body in a straight line making approximately a 30º angle.
  3. Holding moderate weight, extend arms down so thumbs are out. 
  4. Extend arms back while pinching shoulder blades together and externally rotating at the shoulder.

• Ball Cobras @ 90º
  1. Start with ball between waist and belly button.
  2. Holding light weight, roll torso over ball crossing arms in front of each other.
  3. Extend back upwards while bringing arms up to 90º, making sure elbows are at or above shoulders height.

• Single Leg DB Cobras
  1. Balancing on one leg slightly bent, keeping back flat, start with light weight in both hands down in front of body.
  2. Extend shoulders back while pinching shoulder blades and externally rotating shoulders so thumbs face up. Hold 2 seconds.

SERRATUS ANTERIOR FOCUS

• Medicine Ball Scapular Punches
  1. Holding push up position with hands on 2 medicine balls, drop shoulder blades down as if pinching a pencil between shoulder blades. 
  2. Raise shoulder blades straight up as high as possible keeping elbows straight.

• Ball Wall Circles
  1. Using small stability ball or medicine ball, lean body towards wall with one arm balancing on ball.
  2. Perform small up and down motions, then small left to right motions, then small circles clockwise and counter-clockwise.
  3. Perform with shoulders parallel to wall, then change so shoulders are perpendicular to the wall.

• Push-Ups w/ Rotation + DB
  1. Perform push up with hands at shoulder width. 
  2. Rotate feet on top of each other, while balancing with one hand, grab light weight.
  3. Keeping elbows locked, rotate upper body to be vertical to the sky.

SUPRASPINATUS FOCUS

• Single Leg Full Can (aka) DB Scaption
  1. Balancing on one leg, start with light weight in both hands down at your sides.
  2. Raise arms in a “Y” position (45º of abduction) to shoulder height.

• Ball Scaptions
  1. Start with ball between waist and belly button.
  2. Keep body in a straight line making approximately a 30º angle.
  3. Holding light weight, extend arms down with thumbs pointing forward.
  4. Raise arms up at a 45º angle to parallel with the ground. Hold 2 seconds.

EXTERNAL ROTATOR FOCUS

• Single-Arm Cable External Rotation
  1. Keep elbow bent at 90º tight to body.
  2. Hold cable with arm across body.
  3. Rotate shoulder outward away from body.

• Single-Leg Cable Shoulder Extension w/ External Rotation
  1. Balancing on one leg, slightly bend knee while keeping back straight.
  2. Hold cable out in front of body.
  3. Extend shoulder while externally rotating so thumb points away from body.

• Single Leg Cable Diagonal Flexion
  1. Balancing on one leg, hold cable in throwing hand across opposite hip.
  2. Raise arm up across body as if pulling out a sword, making sure elbow is at or above shoulder height.

• Body Blade Overhead Motion
  1. Start by holding the Body Blade overhead with your legs in a lunge stance.
  2. The goal is to keep oscillating the body blade throughout a full range of motion from the “acceleration phase” through the “follow-through phase.”

• Kneeling Medicine Ball External Rotations at 90º/90º/90º
  1. Kneel with throwing hand at 90º/90º/90º position. 
  2. Partner shall have a light MB to toss and “lead” your hand
  3. Be sure to keep elbow still as shoulder rotates 180º.
  4. Explosively “fire” the MB back to partner to catch and throw again.

**NOTE** Communication is key between partners. Decide the number of reps before starting exercise.

• Kneeling Medicine Ball Decelerations
  1. Kneel with hand at 90º/90º/90º position. 
  2. Partner shall have a light MB to toss and “lead” your hand.
  3. Follow through with normal motion having hand pass opposite leg.
  4. Explosively “fire” the MB back to partner to catch and throw again.

• Standing Medicine Ball Decelerations
  1. Stand w/hands extended ready to catch MB. 
  2. Partner shall have a heavy MB to toss and “lead” your hands.
  3. Follow through with normal throwing motion having hands pass opposite leg.
  4. Explosively “fire” the MB back to partner to catch and throw again.

Conclusion

Shoulder pain during the competitive season is a common complaint for many overhead athletes, often due to muscle imbalances and shoulder impingement. Since it is easier to prevent injuries before they happen, incorporating daily stretches to maintain normal ranges of motion in the shoulder is recommended. Imbalances commonly develop due to overuse of the muscles most heavily recruited during acceleration of the arm. Coaches and trainers can perform simple manual strength tests to determine which muscles are weak for each individual athlete. If significant weakness is noted, specific exercises can be prescribed and incorporated into a full-body training program.

Behind-the-neck exercises like lat pulldowns or military presses, which can cause impingement due to the positioning of the rotator cuff, are contraindicated for shoulder training; these exercises should be performed in front of the head to keep the shoulder in a safer position. Every training program should be progressive in nature, building upon a foundation of stabilization first and preparing the body for the upcoming demands of higher intensity training.

References

1. Clark, M.A., Russell, A.M. (2002) NASM OPT: Optimum performance training for the performance enhancement specialist. Calabasas, CA: National Academy of Sports Medicine.
2. Cools, A.M., Dewitte, V., Lanszweert, F., Notebaert, D., Roets, A., Soetens, B., Cagnie, B., Witvrouw, E.E. (2007). Rehabilitation of scapular muscle balance: which exercises to prescribe? American Journal of Sports Medicine, 35(10), 1744-1751.
3. Decker, M.J., Hintermeister, R.A., Faber, K. J. & Hawkins, R.J. (1999). Serratus anterior muscle activity during selected rehabilitation exercises. American Journal of Sports Medicine, 27(6), 784-791.
4. Fleisig, G.S., & Escamilla, R.F., (1996). Biomechanics of the Elbow in the Throwing Athlete. Operative Techniques in Sports Medicine, 4(2), p 62-68.
5. Gross, M.L., Flynn, M., & Sonzogni, J.J. (1994). Overworked shoulders. Physician & Sportsmedicine, 22(3), 81.
6. Kendall, F.P., McCreary, E.K., Provance, P.G., Rodgers, M. & Romani, W. (2005). Muscles: Testing and Function, with Posture and Pain. Philadelphia, PA: Lippincott Williams & Wilkins.
7. Page, P. (2011). Shoulder muscle imbalance and subacromial impingement syndrome in overhead athletes. International Journal of Sports Physical Therapy, 6(1), 51-58.
8. Saccol, M.F., Gracitelli, G.C., da Silva, R.T., Laurino, C. F. & da Silva, A.C. (2010). Shoulder functional ratio in elite junior tennis players. Physical Therapy In Sport: Official Journal Of The Association Of Chartered Physiotherapists In Sports Medicine, 11(1), 8-11.
9. Treiber, F.A., Lott, J., Duncan, J., Slavens, G. & Davis, H. (1999). Effects of Theraband and lightweight dumbbell training on shoulder rotation torque and serve performance in college tennis players. Chiropractic Technique, 11(2), 88-88.