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Progressive Exercise Strategies to Mitigate Shoulder Injuries Among Weight-Training Participants

Escalante, Guillermo DSc, MBA, ATC, CSCS, CISSN1; Fine, Daniel SPT, CSCS2; Ashworth, Kyle SPT, CSCS2; Kolber, Morey J. PT, PhD, CSCS2

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Strength and Conditioning Journal: February 2021 - Volume 43 - Issue 1 - p 72-85
doi: 10.1519/SSC.0000000000000547
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Abstract

INTRODUCTION

The American College of Sports Medicine guidelines recommend that all adults should implement resistance training to all major muscle groups 2–3 days per week (15); this is partly due to the overwhelming evidence that resistance training has positive effects on the musculoskeletal system as well as in the prevention of osteoporosis, sarcopenia, lower back pain, and other disabilities (48). Because of well-known health and fitness benefits, weight-training (WT) participation has gained significant popularity over the last several decades with an estimated 45 million Americans engaging in resistance training regularly (6). Although the health benefits associated with WT are well-known, evidence suggests that there are risks of injury associated with the activity (16,25,26,35,41,42). Similar to aerobic exercise, the risk of sustaining an activity-related injury has been reported to increase with higher duration of physical activity per week (21). To minimize the risk of injury, appropriate exercise technique, selection, and progression may minimize those risks.

Researchers have reported that up to 36% of injuries and disorders in the WT population occur at the shoulder complex (16,25,35,36). There are some potential explanations for the relatively high rate of injuries to the shoulder region. The high degree of mobility allowed by the shoulder joint comes at an exchange of relatively decreased stability. Researchers have hypothesized that most WT programs emphasize large muscle groups that produce strength and hypertrophy, subsequently neglecting stabilizing muscles of the shoulder such as the external rotators (17). Furthermore, the shoulder, which is traditionally a non–weight-bearing joint, has to assume the role of a weight-bearing joint during the course of repetitive lifting stress placed on the shoulder with WT (28). In addition, common resistance training exercises frequently place the shoulder in injury-prone positions with heavy loads such as end range of motion external rotation with the arm abducted (14). It should also be noted that novice participants may also predispose themselves to injury by prematurely loading their shoulder(s) with more advanced lifts without allowing for necessary progression with appropriate technique.

REVIEW OF LITERATURE

Because of the high prevalence of injuries to the shoulder complex among WT participants, researchers have investigated shoulder joint and muscle characteristics in healthy men and women in the recreational WT population (27,31) as well as in the WT population with shoulder pathologies such as subacromial impingement (30,34), anterior glenohumeral instability (32), and hyperlaxity (32). In one study, shoulder joint and muscle characteristics were investigated and compared among WT participants and controls (27). In the aforementioned study, 90 men between the ages of 19–47 years were recruited, which comprised 60 individuals who participated in upper extremity WT and 30 controls who did not perform WT. All participants underwent an assessment of active range of motion (AROM), posterior shoulder tightness (PST), bodyweight-adjusted strength values, and agonist to antagonist strength ratios. Briefly, the authors assessed muscle groups and actions that function as force couples. Specifically, the authors assessed muscle groups that function together to achieve shoulder movements. For example, the authors assessed and compared the strength of the shoulder abductors to the external rotators as well as the upper to the lower trapezius muscle groups and then calculated the ratios. Higher ratios implied greater imbalances. The researchers reported that the WT participants had decreased mobility when compared with the control group for all AROM measurements except external rotation, which was greater. Strength ratios were significantly greater in the WT group when compared with the control group (p < 0.001), implying agonist to antagonist muscle imbalances. Specifically in men, the strength of the larger muscle groups was disproportionately stronger than the smaller stabilizing musculature (e.g., rotator cuff and scapular stabilizers). For example, the authors reported an upper trapezius to lower trapezius ratio of 8.04 in the WT group compared with 5.65 in the control group. Although it is expected that the upper trapezius would have greater strength than the lower trapezius, the authors identified a greater imbalance in the WT participants. These particular imbalances are of interest because they have been associated with shoulder disorders in the general and athletic population, which is inclusive of WT participants (30,32,34).

In a similar study (31), asymptomatic females who participated in WT were assessed for AROM, PST, glenohumeral joint laxity, bodyweight-adjusted strength values, and agonist to antagonist strength ratios. The authors identified significant differences (p < 0.004) between the WT participants when compared with controls when analyzing shoulder internal rotation AROM, PST, and glenohumeral joint laxity. Specifically, the WT participants had decreased internal rotation AROM, greater PST, and an increased prevalence of anterior GH joint hyperlaxity when compared with the control group. No differences in strength ratios between groups were identified (p < 0.109) suggesting the absence of WT-induced muscle imbalances among women.

A body of descriptive evidence has suggested that WT participants may be at risk for subacromial shoulder impingement syndrome (also referred to as subacromial pain syndrome), hereafter referred to as impingement syndrome (30). In the aforementioned study, a clinical testing cluster for impingement syndrome was performed on 46 individuals who participated in WT and compared with 31 controls who had no history or WT participation or sporting activities. Results of this study indicated that 20% of WT participants were positive on a testing cluster for impingement compared with 5% of the controls (p < 0.001). Specifically, the testing cluster used (Hawkins–Kennedy and positive painful arc sign) has been shown to have a positive likelihood ratio of 5.0 for the diagnosis of impingement syndrome (40). A positive likelihood ratio of 5.0 suggests that individuals testing positive (pain during testing) are 5 times more likely to have the condition as opposed to having false positive results. In the same study, exercise selection was analyzed to determine if, indeed, an association existed between the prevalence of impingement syndrome and routinely performed exercises. Interestingly, those who performed lateral deltoid raises above shoulder height (90°) or upright rows where the elbows elevated above shoulder height were more likely to have a positive testing cluster as compared to those who did not perform such exercises. Furthermore, those who routinely performed external rotator strengthening were less likely to present with shoulder impingement.

In another study (34), WT participants with shoulder impingement syndrome (N = 24) confirmed by clinical examination using the same testing cluster previously described, were compared to WT participants without impingement syndrome (N = 31) to determine differences in muscle performance and mobility. Results of this investigation indicated that WT participants with impingement syndrome had reduced shoulder internal and external rotation AROM (<0.017) and decreased bodyweight-adjusted strength values of the external rotator and lower trapezius musculature (p < 0.03) when compared to WT participants without impingement. Furthermore, bodyweight-adjusted strength values of the upper trapezius were greater among WT participants. In addition, strength ratio imbalances were more prevalent among WT participants with impingement syndrome, suggesting training bias with efforts to target the larger upper trapezius and lateral deltoid and with reduced emphasis on the smaller stabilizing muscles such as the external rotators and lower trapezius (p < 0.005).

In a study investigating the presence of clinical signs of anterior instability and hyperlaxity using previously validated clinical testing (32), 123 WT participants and 36 controls were evaluated. Researchers identified a greater prevalence of clinical signs and symptoms of anterior glenohumeral instability and hyperlaxity among the WT participants when compared with the control subjects (p < 0.005). In the aforementioned study, the authors also sought to determine whether there was an association between clinical findings and exercise selection. Results suggested that those individuals with shoulder anterior instability and hyperlaxity were more likely to perform exercises in the “high-five” position (Figures 1 and 2), defined as the humerus in 90° of external rotation simultaneously with 90° of shoulder abduction. Moreover, individuals who performed external rotator strengthening were less likely to have clinical signs of anterior instability and hyperlaxity. Although causative effects should not be extrapolated from descriptive studies using association type data, trends that are biomechanically plausible should not be overlooked in the absence of prospective investigations.

Figure 1.
Figure 1.:
Behind the neck lat pull-down exercise (high-five position-associated with shoulder injury).
Figure 2.
Figure 2.:
Pec deck exercise (high-five position-associated with shoulder injury).

EXERCISES ASSOCIATED WITH SHOULDER INJURY

There are specific WT exercises that have been shown to place the shoulder joint at risk. The Table summarizes some of the exercises that have been associated with injuries to the shoulder. Reeves et al. (41,42) suggested that exercises placing the humerus in a position of extension past the trunk could contribute to anterior shoulder instability and rotator cuff injuries. Similarly, Haupt (19) associated osteolysis of the distal clavicle with the bench press during the eccentric phase of the exercise when the humerus is extended posterior to the trunk due to the repeated microtrauma at the acromioclavicular joint. Modifications to the bench press such as placing a pad on the chest or bar itself would limit the amount of humeral extension that occurs past the trunk (12,28).

Table - Strength training exercises associated with shoulder injury
Exercises commonly associated with injury Shoulder injuries and disorders
1. Flat bench press Osteolysis of the distal clavicle (weightlifter's shoulder) (12,18)
1. Military press
2. Upright row
3. Side raise
Soft tissue damage to the rotator cuff (mainly supraspinatus) and the long head of the biceps at the shoulder origin inclusive of tendinosis, bursitis, tears, and shoulder impingement (9,12,18,19,25,27)
1. Flat bench press
2. Behind the neck lat pull-downs
3. Military press
4. Chest fly/pec deck
5. Snatch
Anterior shoulder instability, glenohumeral capsular hyperlaxity, or dislocations (9,12,28,32)

There are other commonly performed WT exercises that may place the shoulder joint at risk. Exercises that regularly place the shoulder joint in the “high-five” position have been identified as potentially hazardous to the shoulder joint due to the increased stress placed on the anterior shoulder tissues (3,9,12,14,16). Placing the shoulder in this “high-five” position repeatedly with heavy loads may contribute to hyperlaxity or instability to the static glenohumeral ligamentous capsular restraints (4,12,16,19). Jobe et al. (24) suggested that the dynamic rotator cuff muscles likely exert a greater force to stabilize the humeral head when hyperlaxity or instability occurs at the shoulder. This repetitive dynamic compensation of the rotator cuff may result in fatigue followed by tendinosis and pain in the rotator cuff.

Exercises in which the humerus is internally rotated during shoulder abduction may also put the shoulder at risk for impingement. Researchers have reported that avoiding the upright row and lateral deltoid raises beyond an angle of 90° of shoulder abduction could potentially decrease the likelihood of sustaining shoulder impingement (30). In agreement with this statement, Hawkins et al. (20) reported that if the arm is internally rotated during elevation, the greater tuberosity of the humerus pinches the rotator cuff tendons and bursa against the acromion.

Exercises such as behind the neck lat pull-downs (Figure 1) and the chest fly-pec deck (Figure 2) are examples where the high-five position occurs. Modifying the chest fly-pec deck to avoid the end range and performing lat pull-downs to the front would be reasonable modifications. Other reasonable modifications to avoid some of these positions would include limiting lateral deltoid raises to below 90° (Figure 3) and limiting upright rows to a position where the elbows are not raised above 90° (Figure 4). Readers desiring more detailed information on WT modifications to prevent and train around shoulder pain are encouraged to review previously published articles in the Strength and Conditioning Journal (8,12).

Figure 3.
Figure 3.:
Lateral deltoid raise to below 90° angle.
Figure 4.
Figure 4.:
Upright rows with elbows raised to below 90° angle.

PREVENTIVE STRATEGIES FOR SHOULDER INJURIES

Based on the literature presented, muscular imbalances in the shoulder complex exist and may contribute to some of the shoulder injuries commonly encountered by WT participants as a result of training patterns. To provide a logistic and effective evidence-based program to help minimize shoulder injuries, the following information will be used as a theoretical construct:

  1. WT participants may have increased external rotation as well as decreased shoulder internal rotation, flexion, and abduction AROM (27,31).
  2. WT participants are likely to develop PST (27,31).
  3. Strength ratios among male WT participants indicate that larger muscle groups (e.g., lateral deltoids, upper trapezius, and pectoralis major) are disproportionately stronger than the smaller stabilizing musculature (e.g., lower trapezius, serratus anterior, and infraspinatus-teres minor) (27).
  4. WT participants who routinely perform external rotator strengthening are less likely to present with shoulder impingement (30) and to have clinical signs of anterior instability and hyperlaxity (32).
  5. Thoracic extension is a necessary biomechanical requirement for shoulder elevation, and both limited thoracic extension and increased kyphosis are associated with reduced shoulder range of motion and impingement (2,10,22,23,47).

The progressive exercise program presented is based on the aforementioned range of motion deficits and muscular imbalances as well as the implementation of appropriate stabilization exercises for the smaller muscle groups that can be incorporated into an overall strength training program.

MUSCLE PERFORMANCE

The progressive approach to muscle performance will present exercises designed to target key muscles with an understanding that correcting muscle imbalances is a prerequisite to achieving higher levels of activation. Specifically, the lower trapezius, serratus anterior, infraspinatus, and teres minor musculature will be addressed with an approach that requires early exercises designed to isolate the aforementioned musculature. Isolation will lend to mitigating imbalances. Once isolation is achieved, then the progression to more functional and higher muscle activation exercises is recommended. Premature progression to exercises that maximally recruit the desired musculature (as opposed to isolation) may perpetuate muscle imbalances.

LOWER TRAPEZIUS

The lower trapezius is a scapular stabilizer and is responsible for scapular depression. The goal for addressing the lower trapezius initially includes exercises designed to isolate the muscle without high activation of the lateral deltoids and upper trapezius. The purpose of isolating the lower trapezius without concurrent recruitment of larger muscles is designed to mitigate shoulder imbalances. The initial exercise performed for the lower trapezius includes the modified prone cobra (Figure 5A and 5B). This exercise, when performed appropriately, targets the lower trapezius and minimizes activity of the upper trapezius when compared with more advanced exercises such as the prone scapular Y (1). For the modified prone cobra, resistance is not a factor for loading as the goal of the exercise is to perform the movement in a correct manner while activating the lower trapezius and minimizing recruitment of the upper trapezius. Since this exercise is focused on recruitment of the muscle with proper technique and there are no dosing guidelines for this exercise, we recommend performing this exercise daily using hold times ranging from 10 to 30 seconds for 10 repetitions. Performing this exercise correctly will permit the necessary recruitment. Once an individual masters the ability to recruit the lower trapezius accordingly, the progression for strengthening the lower trapezius would be the prone scapular Y exercise (Figure 6A and 6B). This exercise is a progression because it targets the lower trapezius with maximal activation; however, it recruits the upper trapezius and lateral deltoids as well (1,11,13). For example, when determining muscle activity, electromyography is used and the muscle activation is often presented as a percentage of the maximum voluntary isometric contraction (MVIC) activation. The MVIC is usually determined during an isometric muscle action, which is then used to determine a dynamic activity's percentage of the MVIC. In the case of the prone scapular Y, the lower trapezius is recruited at 97% MVIC with the upper trapezius at 79% MVIC and the lateral deltoid at 82% MVIC (11,43). Performing this particular exercise before learning appropriate recruitment of the lower trapezius may perpetuate imbalances in the shoulder because it recruits the lateral deltoids and upper trapezius at fairly high levels.

Figure 5.
Figure 5.:
(A) Start of modified prone cobra; client positioned on stomach, arms by side, and palms up toward ceiling. (B) Execution of modified prone cobra; cue client to retract (pinch shoulder blades together) and depress scapula (arrow identifies position of depression). While maintaining scapular retraction and depression, the client is instructed to slightly extend the thoracic spine (elevate chest off table) and reach fingertips toward toes to assist with maintaining scapular depression.
Figure 6.
Figure 6.:
(A) Start of prone scapular Y; client positioned on stomach on elevated surface. (B) Execution of prone scapular Y; cue client to elevate arm in scapular plane, thumb up, and elbow extended.

SERRATUS ANTERIOR

The serratus anterior serves to stabilize the scapula and is responsible for the scapular motions of external rotation, protraction, and upward rotation. The goal for addressing the serratus anterior initially includes exercises designed to activate the muscle without high activation of lateral deltoids and upper trapezius. Like the modified prone cobra, the purpose of isolating the serratus anterior without concurrent recruitment of larger muscles is also designed to mitigate shoulder imbalances. The initial exercise performed for the serratus anterior is the supine punch (Figure 7A and 7B). The punch isolates the serratus anterior while minimally activating the upper trapezius (11). When evaluating the MVIC, one study indicated a 62% MVIC of the serratus anterior with a 7% MVIC of the upper trapezius (11). Dosing for the punch exercise generally would follow guidelines for muscular endurance at 2–3 days per week with repetitions in the 12–20 RM range with 30-second interset rest periods. The progression of the punch exercise would be the push-up plus (Figure 8A and 8B) and ultimately the upper cut (Figure 9A and 9B). The push-up plus recruits the serratus anterior at >73% MVIC with less than 50% MVIC for the upper trapezius, whereas the upper cut recruits the serratus anterior at approximately 100% MVIC with the upper trapezius at 66% (11,38). Note that performing the upper cut or push-up plus before learning to recruit and isolate the serratus anterior may perpetuate shoulder imbalances. The push-up plus would be dosed similar to the modified prone cobra, whereas the upper cut would be dosed within the guidelines recommended for the serratus punch. Although the aforementioned exercises provide a practical progression, the serratus anterior is also activated during overhead shoulder range of motion. Further to this point, the serratus anterior activity is increased with increasing ranges of shoulder elevation (18). An additional advancement to the previously mentioned serratus anterior progression is to add the wall slide exercise (5,18). This exercise requires the client to place the ulnar aspect of the hands in contact with a wall and slide the hands up the wall (in the scapular plane) while pushing into the wall. An elastic band could be placed around the wrists to increase the challenge during elevation as shown in Figure 10A and 10B.

Figure 7.
Figure 7.:
(A) Start of serratus punch; client positioned on back, hand stacked on top of shoulder, and elbow extended. (B) Execution of serratus punch; provide resistance through band/dumbbell/kettlebell; cue client to reach/punch towards ceiling while maintaining elbow extension; and return to (A).
Figure 8.
Figure 8.:
(A) Start of push-up plus; client positioned in push-up position, cue to retract scapula (pinch shoulder blades together). (B) Execution of push-up plus; cue client to protract scapula (push floor away and protract [spread] shoulder blades).
Figure 9.
Figure 9.:
(A) Start of upper cut; client begins standing with arm by side. (B) Execution of upper cut; cue client to protract scapula, adduct (ADD), and externally rotate (ER) the humerus (elbow moves medially and hand moves laterally); return to (A).
Figure 10.
Figure 10.:
(A) The wall slide exercise begins with the ulnar side (little fingers) of hands in contact with a wall and a resistance elastic band around wrists. The individual pushes hands into wall and begins to ascend up the wall (elevation of shoulder) while maintaining pressure of hands into wall. During this phase, cues are provided to ensure that pressure into the wall is maintained, and wrists are kept at a distance against the resistance of the elastic band. (B) During the wall slide, the goal is to slide up the wall (shoulder elevation) maintaining pressure and keeping wrists apart. Pressure should be maintained into the wall during both phases of exercise (shoulder elevation and during the return to A).

INFRASPINATUS AND TERES MINOR

The infraspinatus and teres minor musculature serve as external rotators and stabilizers of the glenohumeral joint. The goal for addressing these muscles at first is isolation with minimal activation of the anterior and lateral deltoids. The first exercise used for isolation of the infraspinatus and teres minor includes standing external rotation with elastic tubing or a cable device (Figure 11A and 11B). Standing external rotation using elastic tubing or cable in the 0° abducted position recruits the lateral deltoid at approximately 8% MVIC as compared to 50% MVIC when the arm is in an abducted position (39). Although not pictured, external rotator strengthening may be performed in the sidelying position with comparable recruitment patterns as standing with arm in 0° abduction. Note that optimal form for this exercise requires the use of a small towel roll between the elbow and side. Readers desiring a more detailed explanation of the purpose of using the towel roll are encouraged to review a previously published article in the Strength and Conditioning Journal (29). The progression of external rotation with the arm adducted to the side would be to perform the exercise with the arm abducted to approximately 80° as shown in Figure 12A and 12B. Note that this exercise activates the lateral deltoids at a high level (50% MVIC as compared to 8% MVIC with 0° abduction) and would not be appropriate to perform in the early stages of a program because it would perpetuate muscle imbalances. In both of these exercises we recommend dosing within the ranges discussed for the serratus punch.

Figure 11.
Figure 11.:
(A) Start of shoulder external rotation (no shoulder abduction); client begins standing, 6″ towel roll between elbow and rib cage, elbow flexed to 90°, palm on stomach. (B) Execution of shoulder external rotation (no shoulder abduction); cue client to bring back of hand toward opposite wall, ending in slight externally rotate (ER) past neutral; return to (A) under control.
Figure 12.
Figure 12.:
(A) Start of shoulder external rotation (with shoulder abduction); client begins standing, arm in 90° ABD, 90° elbow flexion, and cable anchored in front of client at level of hips. (B) Execution of shoulder external rotation (with shoulder abduction); cue client to bring back of hand toward the ceiling until 90/90 position is attained; return to (A) with control.

POSTERIOR SHOULDER TIGHTNESS

Because PST has been associated with shoulder pain among WT participants, efforts to address this impairment should be part of a comprehensive program. The sleeper and the cross-arm stretches are 2 stretches that can address PST and may be used with their own progressions. In both of these stretches, the scapula should be stabilized to prevent compensatory movement, which will allow for better isolation of the region (44). Stretching should be performed daily for 3- to 30-second holds. Readers desiring more detailed information on the underlying etiology and interventions for PST as well as measurements designed to quantify a mobility loss are encouraged to review previously published articles in the Strength and Conditioning Journal (7,33).

SLEEPER STRETCH

The sleeper stretch can be performed sidelying or standing. When performed standing, the individual stands against a wall with the lateral aspect of scapula weight bearing into the wall for stability as shown in Figures 13A and 14A. We recommend beginning with the arm abducted (elevated) to approximately 45° (Figure 13A and 13B) and progressing to a 90° angle as tolerated for a greater stretch (Figure 14A and 14B). Note that the stretch involves weight bearing into a wall to stabilize the scapula while maintaining the arm in either 45 or 90° abduction. Once in this position, the opposite arm is used to bring the stretched arm into internal rotation (toward the wall). For individuals who have pain or discomfort at the end range of the stretch, a lacrosse ball may be placed at the posterior shoulder as shown in Figures 13C and 14C. Placing a ball in this location will pin down the contractile tissue and produce a stretch earlier in the range.

Figure 13.
Figure 13.:
(A) Start of stage 1 sleeper stretch; client standing with lateral aspect of scapula weight bearing into wall and arm to be stretched at 45° ABD with 90° elbow flexion on wall. (B) Execution of stage 1 sleeper stretch; contralateral arm pushes forearm and wrist of arm to be stretched into wall (achieving internal rotation) while maintaining scapular stabilization through wall contact. (C) Progression of stage 1 sleeper stretch; add lacrosse ball at posterolateral shoulder while performing stretch in (B).
Figure 14.
Figure 14.:
(A) Start of stage 2 sleeper stretch; client standing with lateral aspect of scapula weight bearing into wall and arm to be stretched at 80° ABD with 90° elbow flexion on wall. (B) Execution of stage 2 sleeper stretch; contralateral arm pushes forearm and wrist of arm to be stretched into wall while maintaining scapular stabilization through wall contact. (C) Progression of stage 2 sleeper stretch; lacrosse ball at posterolateral shoulder while performing stretch in (B).

CROSS-ARM STRETCH

The cross-arm stretch is an alternate to the sleeper stretch. This stretch, similar to the sleeper, involves stabilizing the scapula against a wall. Once stabilized, the arm is brought to a 90° angle as shown in Figure 15A. Once in position, the opposite arm is used to passively adduct the arm (cross-arm over body) as shown in Figure 15B. Similar to the sleeper stretch, a lacrosse ball may (Figure 15C) be used as an adjunct to the stretch and can be performed in sidelying as a means of stabilizing scapula. Stabilizing the scapula is a key element of this stretch because evidence suggests greater improvements in flexibility when compared with a cross-arm stretch without stabilization (44).

Figure 15.
Figure 15.:
(A) Start of cross-arm stretch; client standing with lateral aspect of scapula weight bearing into wall. (B) Execution of cross-arm stretch; contralateral arm pulls arm to be stretched across body through horizontal ADD while maintaining scapular stabilization through wall contact. (C) Progression of cross-arm stretch: add a lacrosse ball at posterolateral shoulder while performing stretch in (B).

The choice of whether an individual performs the sleeper or cross-arm stretch should be based on comfort because the sleeper stretch may be painful among individuals with existing shoulder pathology. A body of evidence among different populations has indicated that the cross-arm stretch may be more effective than the sleeper stretch. Of importance to consider is that one of these studies used a postoperative population (45) and the other (37) did not report clinically significant differences. Furthermore, a body of evidence suggests that there are numerous options to improve PST with multiple treatments (i.e., stretch and soft tissue mobilization) being efficacious when compared with a single intervention (46).

THORACIC EXTENSION

Evidence has suggested that thoracic spine mobility is needed for biomechanically correct shoulder movements when reaching overhead. In one study, it was reported that during bilateral arm elevation, there was a mean increase of 11–13° of thoracic extension (10). Further to this point, another study reported that individuals with impingement syndrome had greater kyphosis and decreased thoracic extension when compared with an asymptomatic group (22). As a result of these findings, ensuring adequate thoracic extension would seem reasonable as would correct thoracic posture during overhead WT movements. In our experience, thoracic posture can be improved through education; however, restricted thoracic extension may be improved with specific stretching exercises. One suggestion for improving thoracic extension in a fitness setting would be to sit backward on a preacher curl device, so that the arm pad is at the level of the thoracic spine. Once in this position, arching backward as shown in Figure 16 would increase thoracic extension range of motion. An alternate stretch to increase thoracic extension would consist of lying supine on a foam roll positioned at the thoracic spine while holding a kettlebell overhead as shown in Figure 17. Stretches may be held for a duration of 30 seconds and repeated 3–5 times.

Figure 16.
Figure 16.:
(A) Seated thoracic extension using a preacher curl device; client is seated backward with arm pad at the level of the thoracic spine. (B) Once in position the client arches back into thoracic extension.
Figure 17.
Figure 17.:
(A) Foam roll thoracic extension; client is positioned supine over foam roll. (B) With arms in a sustained overhead position, client uses a kettlebell to facilitate a stretch into thoracic extension.

CONCLUSION

The shoulder complex is a commonly injured body part among WT participants. Based on the current available evidence, imbalances in the shoulder complex exist and may contribute to some of the shoulder injuries commonly encountered by WT participants; this may partly be due to training practices. Evidence suggests that WT participants may have increased external rotation AROM as well as decreased AROM for shoulder internal rotation, flexion, and abduction AROM (27,31). Furthermore, WT participants are likely to develop PST (27,31) and male WT participants seem to have disproportionately stronger larger muscle groups (e.g., lateral deltoids, upper trapezius, and pectoralis major) as compared to the smaller stabilizing musculature (e.g., lower trapezius, serratus anterior, and infraspinatus-teres minor) (27). Finally, WT participants who routinely perform external rotator strengthening are less likely to present with impingement syndrome (30) and to have less clinical signs of anterior instability and hyperlaxity (32). Methodically addressing the imbalances in the shoulder complex that have been reported among WT participants by implementing the recommended exercises and progressions may help to reduce the rates of shoulder injuries among the WT population. Furthermore, modifying the upper-body exercises that may predispose the shoulder to injury and ensuring proper technique/progressions are implemented with all exercises may further reduce the occurrence of injuries to the shoulder region among this population.

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Keywords:

bodybuilding; injury; powerlifting; resistance training; shoulder; weightlifting

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