Anterior shoulder instability in weight lifters

Prevalence and Pattern of Injuries Across the Weight-Training Sports

Background The prevalence and pattern of injury among weightlifters are insufficiently documented despite these research works. Understanding the injury pattern is crucial for minimizing side effects and maximizing the advantages of weight training. Therefore, the purpose of this study is to determine the frequency and pattern of musculoskeletal injury among weightlifters and to investigate the associations between the prevalence of injury and sociodemographic and training characteristics variables. Methods A descriptive cross-sectional, questionnaire-based study was conducted. An online questionnaire was designed by Google Forms to collect the data by using a self-administered questionnaire. From all health clubs in Taif city, Saudi Arabia, one club was chosen by simple random sampling methodology, where all attendant weightlifters during the study period were contacted to participate in the study. Data was entered on the computer using Microsoft Office Excel 2016 for Windows. Qualitative data was expressed as numbers and percentages, and the Chi-squared test (χ2) was used to assess the relationship between variables. A p-value < 0.05 was considered statistically significant. Results The study included 393 participants, and most respondents fall within the age range of 18-29, accounting for 60.1% of the total. About 27% of participants had a weightlift injury during the last six months. The body parts most injured during weightlifting include the shoulder (7.4%), knee (4.6%), and wrist (3.6%). In terms of the type of injuries sustained, inflammation and pain in the bending of the body (5.9%), torsion (3.6%), ligament tear/muscle tear (3.8%), and stripped-off injuries (2.3%) were reported. Conclusion Musculoskeletal injuries are prevalent among weightlifters due to the nature of the sport and the demands it places on the body. There was no significant association between the injury occurrence with gender, age, or body mass index. However, there was a significant association between the occurrence of injury and weight carried while lifting weights.

Self-Massage Techniques for the Management of Pain and Mobility With Application to Resistance Training: A Brief Review

ABSTRACT

MacLennan, M, Ramirez-Campillo, R, and Byrne, PJ. Self-massage techniques for the management of pain and mobility with application to resistance training: a brief review. J Strength Cond Res 37(11): 2314-2323, 2023-Fascial restrictions that occur in response to myofascial trigger points (MTrP), exercise-induced muscle damage (EIMD), and delayed onset of muscle soreness (DOMS) cause soft tissue to lose extensibility, which contributes to abnormal muscle mechanics, reduced muscle length, and decrements in joint range of motion (ROM) and actively contributes to musculoskeletal pain. Resistance training and in particular, weightlifting movements have unique mobility requirements imperative for movement efficacy and safety with ROM restrictions resulting in ineffective volume and intensity tolerance and dampened force output and power, which may lead to a failed lift or injury. Self-massage (SM) provides an expedient method to promote movement efficiency and reduce injury risk by improving ROM, muscular function, and reducing pain and allows athletes to continue to train at their desired frequency with minimal disruption from MTrPs-associated adverse effects. Thus, the aim of this review was to determine the efficacy of various self-massage tools in managing pain and mobility and to explore the potential benefits of SM on resistance training performance. Many SM devices are available for athletes to manage ROM restrictions and pain, including differing densities of foam rollers, roller massagers, tennis balls, and vibrating devices. To attenuate adverse training effects, a 10-to-20-minute bout consisting of 2-minute bouts of SM on the affected area may be beneficial. When selecting a SM device, athletes should note that foam rollers appear to be more effective than roller massagers, with vibrating foam rollers eliciting an increased reduction to pain perception, and tennis balls and soft massage balls were shown to be efficacious in targeting smaller affected areas.

Comparison of Muscle Activity between the Horizontal Bench Press and the Seated Chest Press Exercises Using Several Grips

This study aims to compare muscle activity in the pectoralis major, anterior deltoid, and triceps brachii in the horizontal bench press exercise with a prone grip at 150% and 50% of the biacromial width and the seated chest press exercise with two types of grips (a neutral grip at ~150% of the biacromial width and a prone grip at ~200% of the biacromial width). Twenty physically active adults performed a set of 8 repetitions at 60% of the one repetition maximum. The results showed that the clavicular portion of the pectoralis major had significantly greater muscle activity in the seated chest press exercise with a neutral grip (~30% of the maximal voluntary isometric contraction (MVIC)) than in the lying bench press exercise with a prone grip at 150% of the biacromial width (~25% MVIC). The muscle activity of the anterior deltoid was not significantly different across any exercise or grip evaluated (~24% MVIC). The muscle activity of the triceps brachii was significantly higher in the lying bench press exercise with a grip at 50% biacromial width (~16% MVIC) than at 150% of the biacromial width (~12% MVIC). In conclusion, all exercises and grips showed similar muscle activity, and the selection of these exercises should not be based exclusively on the grounds of muscle activation but rather on the load capacity lifted, the level of technique of the participant, and/or the transference to the specific sporting discipline or event.

Bench, Bar, and Ring Dips: Do Kinematics and Muscle Activity Differ?

The purpose of this study was to profile and compare the kinematics, using 3D motion capture, and muscle activation patterns, using surface electromyography (sEMG), of three common dip variations; the bench, bar, and ring dips. Thirteen experienced males performed four repetitions of each dip variation. For each participant, repetitions 2-4 were time-normalized and then averaged to produce a mean value for all kinematic and sEMG variables. The mean maximal joint angles and mean peak sEMG amplitudes were compared between each variation using a one-way ANOVA with repeated measures. Several significant differences (p < 0.05) between dip variations were observed in both kinematic and sEMG data. The bench dip predominantly targets the triceps brachii but requires greater shoulder extension range. The mean peak triceps brachii activation was 0.83 ± 0.34 mV on the bench, 1.04 ± 0.27 mV on the bar, and 1.05 ± 0.40 mV on the ring. The bar dip is an appropriate progression from the bench dip due to the higher peak muscle activations. The ring dip had similar peak activations to the bar dip, with three muscles increasing their activation intensities further. These findings have implications for practitioners prescribing the dip, particularly to exercisers with a history of shoulder pain and injury.

Joint and muscle injuries in men and women CrossFit® training participants

OBJECTIVE

Verify the incidence and rate of joint and muscle injuries with the practice of CrossFit® and the potential risk factors for injuries in men and women.

METHODS

A total of 184 CrossFit® participants (97 men and 87 women). A questionnaire was conducted based on characterization, training routine, injuries, and additional information. The incidence refers to the number of new cases of injury in the sample during the CrossFit® training. The injury rate was calculated by estimating the number of weekly training hours and converted into the number of injuries per 1000 training hours.

RESULTS

Among the participants, 38.6% reported some type of injury, being joint injuries (83.1%) and/or muscle injuries (45.1%). The injury rate was 3.4/1000 h, with men having a higher rate. The location of the joint injuries was shoulders, wrists, and elbows, in addition to the lumbar spine in women. As for muscle injuries, the deltoid, upper back muscles, and quadriceps femoris were the most reported in men and deltoid, trapezius, upper back muscles, and gastrocnemius in women.

CONCLUSIONS

A better understanding of the anatomical distribution of the injuries may help coaches prescribe the most adequate workout that may reduce the likelihood of injuries occurring in CrossFit® training participants. It was demonstrated that gender, experience, weekly frequency, and previous injuries are important factors, and professionals must be concerned with the assessment of the participants and with an individualized progression in order to avoid risks.

Muscle Contraction Has a Reduced Effect on Increasing Glenohumeral Stability in the Apprehension Position

PURPOSE

Glenohumeral instability accounts for 23% of all shoulder injuries among collegiate athletes. The apprehension position-combined shoulder abduction and external rotation-commonly reproduces symptoms in athletes with instability. Rehabilitation aims to increase glenohumeral stability by strengthening functional positions. However, it is unclear how much glenohumeral stability increases with muscle contraction in the apprehension position. The purpose of this study was to determine whether the ability to increase translational glenohumeral stiffness, a quantitative measure of glenohumeral stability, with muscle contraction is reduced in the apprehension position.

METHODS

Seventeen asymptomatic adults participated. A precision-instrumented robotic system applied pseudorandom, anterior-posterior displacements to translate the humeral head within the glenoid fossa and measured the resultant forces as participants produced isometric shoulder torques. Measurements were made in neutral abduction (90° abduction/0° external rotation) and apprehension (90° abduction/90° external rotation) positions. Glenohumeral stiffness was estimated from the relationship between applied displacements and resultant forces. The ability to increase glenohumeral stiffness with increasing torque magnitude was compared between positions.

RESULTS

On average, participants increased glenohumeral stiffness from passive levels by 91% in the neutral abduction position and only 64% in the apprehension position while producing 10% of maximum torque production. The biggest decrease in the ability to modulate glenohumeral stiffness in the apprehension position was observed for torques generated in abduction (49% lower, P < 0.001) and horizontal abduction (25% lower, P < 0.001).

CONCLUSION

Our results demonstrate that individuals are less able to increase glenohumeral stiffness with muscle contraction in the apprehension position compared with a neutral shoulder position. These results may help explain why individuals with shoulder instability more frequently experience symptoms in the apprehension position compared with neutral shoulder positions.

Training with an elastic, supportive bench press device is not superior to a conventional training approach in trained men

The aim of this study was to investigate the effects of an 8‑week powerlifting-type bench press (BP) resistance training (RT) program, either without (RAW) or with using a supportive elastic bench press device (EBD) on one-repetition maximum (1-RM), body weight (BW), mid-upper arm and chest circumference, as well as visual analogue pain scale (VAS) of the shoulder, elbow, and wrist. For this purpose, a matched pair parallel design based on initial 1‑RM was used (BPD n = 16, age 24.4 ± 4 years, RT experience 3.75 ± 1.83 years; RAW n = 16, age 25 ± 2 years, RT experience 5.66 ± 3.00 years). Following two weeks of familiarization with the protocol , BP RT was carried out twice weekly. The EBD group completed more than half of their BP sets with elastic assistance and 10% higher training intensity than the RAW group. There was a significant time × group interaction in BW (p = 0.008). Post hoc analysis showed a significant loss of 0.92 kg in the EBD group (p = 0.049; effect size [ES] = −0.08; 95%CI [−1.80, 0.04]). A significant time effect for 1‑RM was observed (p < 0.001). In both groups there was a significant change in 1‑RM of 5.00 kg (p < 0.001; ES = 0.35; 95%CI [2.98, 7.02]). There was no significant change in any circumference or VAS measure. In conclusion, using an EBD leads to 1‑RM gains similar to conventional RAW BP training. However, more studies are required with highly trained individuals, in particular female athletes. Practitioners may implement EBD training for reasons of variation.

Interprofessional Inconsistencies in the Diagnosis of Shoulder Instability: Survey Results of Physicians and Rehabilitation Providers

BACKGROUND

Clinicians of many specialties within sports medicine care for athletes with shoulder instability, but successful outcomes are inconsistent. Consistency across specialties in the diagnosis of shoulder instability is critical for care of the athlete, yet the extent of divergence in its diagnosis is unknown.

HYPOTHESIS

Physicians differ from rehabilitation providers in which findings they deem clinically important to differentiate shoulder instability from impingement, and in how they diagnose athlete scenarios with atraumatic shoulder instability.

STUDY DESIGN

Cross-sectional study.

METHODS

Physicians (orthopaedic surgeons, primary care sports medicine physicians) and rehabilitation providers (physical therapists, athletic trainers) were asked via an online survey to rate clinical factors used to diagnose shoulder instability. Clinicians were also asked to diagnose two athlete scenarios with concurrent clinical findings of atraumatic shoulder instability and impingement, differentiated by the absence or presence of a positive sulcus sign.

RESULTS

Responses were recorded from 888 clinicians. Orthopaedic surgeons (N=170) and primary care sports medicine physicians (N=108) ranked physical examination factors as more important for the diagnosis of shoulder instability than patient history factors, whereas physical therapists (N=379) and athletic trainers (N=231) preferred patient history factors. Orthopaedic surgeons differed from physical therapists and athletic trainers in their clinical diagnoses for both scenarios (P≤0.001).

CONCLUSION

A lack of consistency exists among sports medicine clinicians in recognizing which clinical factors are important when used to diagnose shoulder instability and in diagnoses given with concurrent findings of impingement.

LEVEL OF EVIDENCE

Level 3.

The Epidemiology of Injuries Across the Weight-Training Sports

BACKGROUND

Weight-training sports, including weightlifting, powerlifting, bodybuilding, strongman, Highland Games, and CrossFit, are weight-training sports that have separate divisions for males and females of a variety of ages, competitive standards, and bodyweight classes. These sports may be considered dangerous because of the heavy loads commonly used in training and competition.

OBJECTIVES

Our objective was to systematically review the injury epidemiology of these weight-training sports, and, where possible, gain some insight into whether this may be affected by age, sex, competitive standard, and bodyweight class.

METHODS

We performed an electronic search using PubMed, SPORTDiscus, CINAHL, and Embase for injury epidemiology studies involving competitive athletes in these weight-training sports. Eligible studies included peer-reviewed journal articles only, with no limit placed on date or language of publication. We assessed the risk of bias in all studies using an adaption of the musculoskeletal injury review method.

RESULTS

Only five of the 20 eligible studies had a risk of bias score ≥75 %, meaning the risk of bias in these five studies was considered low. While 14 of the studies had sample sizes >100 participants, only four studies utilized a prospective design. Bodybuilding had the lowest injury rates (0.12-0.7 injuries per lifter per year; 0.24-1 injury per 1000 h), with strongman (4.5-6.1 injuries per 1000 h) and Highland Games (7.5 injuries per 1000 h) reporting the highest rates. The shoulder, lower back, knee, elbow, and wrist/hand were generally the most commonly injured anatomical locations; strains, tendinitis, and sprains were the most common injury type. Very few significant differences in any of the injury outcomes were observed as a function of age, sex, competitive standard, or bodyweight class.

CONCLUSION

While the majority of the research we reviewed utilized retrospective designs, the weight-training sports appear to have relatively low rates of injury compared with common team sports. Future weight-training sport injury epidemiology research needs to be improved, particularly in terms of the use of prospective designs, diagnosis of injury, and changes in risk exposure.

Perfil de lesões em praticantes de CrossFit: revisão sistemática

RESUMO O CrossFit se apresenta como um novo método de treinamento físico que vem ganhando popularidade desde sua criação. O objetivo deste estudo foi analisar o perfil de lesões em praticantes de CrossFit por meio de uma revisão sistemática da literatura. Utilizaram-se as recomendações da Declaração PRISMA para condução da revisão sistemática. A busca foi realizada nas bases de dados CINAHL, SciELO, Science Direct, SCOPUS, LILACS, PEDro, PubMed, SPORTDiscus e Web of Science. Avaliou-se a qualidade metodológica dos estudos, entre os quais dez foram considerados elegíveis. A prevalência de lesões nos praticantes de CrossFit variou de 5 a 73,5%, e a taxa de lesão variou de 1,94 a 3,1 lesões a cada 1.000 horas de treinamento. A região corporal mais acometida por lesões nos estudos selecionados foram os ombros, seguidos pelas costas e joelhos. Em relação aos fatores associados às lesões, destacou-se o tipo de exercício realizado e o tempo de prática de CrossFit. O sexo apresentou associação com a prevalência de lesões, estudos demonstraram que os homens apresentaram maior número de lesões em relação às mulheres. A idade esteve entre os fatores que não estiveram associados às lesões. Conclui-se que os ombros são a região corporal mais comumente acometida entre os praticantes de CrossFit, em indivíduos do sexo masculino e com lesões prévias, muitas vezes obtidas em outras modalidades. Ainda, que o CrossFit pode ser praticado com segurança por indivíduos de 18 a 69 anos.

Relationships between Mechanical Variables in the Traditional and Close-Grip Bench Press

The study aim was to determine relationships between mechanical variables in the one-repetition maximum (1RM) traditional bench press (TBP) and close-grip bench press (CGBP). Twenty resistance-trained men completed a TBP and CGBP 1RM. The TBP was performed with the preferred grip; the CGBP with a grip width of 95% biacromial distance. A linear position transducer measured: lift distance and duration; work; and peak and mean power, velocity, and force. Paired samples t-tests (p < 0.05) compared the 1RM and mechanical variables for the TBP and CGBP; effect sizes (d) were also calculated. Pearson’s correlations (r; p < 0.05) computed relationships between the TBP and CGBP. 1RM, lift duration, and mean force were greater in the TBP (d = 0.30-3.20). Peak power and velocity was greater for the CGBP (d = 0.50-1.29). The 1RM TBP correlated with CGBP 1RM, power, and force (r = 0.685-0.982). TBP work correlated with CGBP 1RM, lift distance, power, force, and work (r = 0.542-0.931). TBP power correlated with CGBP 1RM, power, force, velocity, and work (r = 0.484-0.704). TBP peak and mean force related to CGBP 1RM, power, and force (r = 0.596-0.980). Due to relationships between the load, work, power, and force for the TBP and CGBP, the CGBP could provide similar strength adaptations to the TBP with long-term use. The velocity profile for the CGBP was different to that of the TBP. The CGBP could be used specifically to improve high-velocity, upper-body pushing movements.

Upper extremity weightlifting injuries: Diagnosis and management

Common upper extremity injuries in resistance training athletes include muscle strains, ligament sprains, pectoralis major tendon ruptures, distal biceps tendon ruptures, and chronic shoulder pain and capsulolabral injuries. While each injury is unique in its specific anatomic location and mechanism, each is preventable with proper exercise technique, safety and maintenance of muscle balance. Conservative treatment is the therapeutic modality of choice and these injuries generally resolve with workout modification, appropriate recovery, anti-inflammatory medication, and physical therapy. If conservative treatment fails, surgical intervention is often successful and can return the weightlifter to a level of performance near their pre-injury level.

An Investigation of the Mechanics and Sticking Region of a One-Repetition Maximum Close-Grip Bench Press versus the Traditional Bench Press

The close-grip bench press (CGBP) is a variation of the traditional bench press (TBP) that uses a narrower grip (~95% of biacromial distance (BAD)) and has potential application for athletes performing explosive arm actions from positions where the hands are held close to the torso. Limited research has investigated CGBP mechanics compared to the TBP. Twenty-seven resistance-trained individuals completed a one-repetition maximum TBP and CGBP. The TBP was performed with the preferred grip; the CGBP with a grip width of 95% BAD. A linear position transducer measured lift distance and duration; peak and mean power, velocity, and force; distance and time when peak power occurred; and work. Pre-sticking region (PrSR), sticking region, and post-sticking region distance and duration for each lift was measured. A repeated measures ANOVA was used to derive differences between TBP and CGBP mechanics (p < 0.01); effect sizes (d) were also calculated. A greater load was lifted in the TBP, thus mean force was greater (d = 0.16⁻0.17). Peak power and velocity were higher in the CGBP, which had a longer PrSR distance (d = 0.49⁻1.32). The CGBP could emphasize power for athletes that initiate explosive upper-body actions with the hands positioned close to the torso.

Effect of Barbell Weight on the Structure of the Flat Bench Press

Król, H and Gołaś, A. Effect of barbell weight on the structure of the flat bench press. J Strength Cond Res 31(5): 1321–1337, 2017—In this study, we have used the multimodular measuring system SMART. The system consisted of 6 infrared cameras and a wireless module to measure muscle bioelectric activity. In addition, the path of the barbell was measured with a special device called the pantograph. Our study concerns the change in the structure of the flat bench press when the weight of the barbell is increased. The research on the bench press technique included both the causes of the motion: the internal structure of the movement and the external kinematic structure showing the effects of the motion, i.e., all the characteristics of the movement. Twenty healthy, male recreational weight trainers with at least 1 year of lifting experience (the mean ± SD = 3.3 ± 1.6 years) were recruited for this study. The subjects had a mean body mass of 80.2 ± 8.6 kg, an average height of 1.77 ± 0.08 m, and their average age was 24.7 ± 0.9 years. In the measuring session, the participants performed consecutive sets of a single repetition of bench pressing with an increasing load (about 70, 80, 90, and 100% of their 1 repetition maximum [1RM]). The results showed a significant change in the phase structure of the bench press, as the barbell weight was increased. While doing the bench press at a 100% 1RM load, the pectoralis major changes from being the prime mover to being the supportive prime mover. At the same time, the role of the prime mover is taken on by the deltoideus anterior. The triceps brachii, in particular, clearly shows a greater involvement.

Injuries among weightlifters and powerlifters: a systematic review

BACKGROUND

Olympic weightlifting and powerlifting are two sports that expose the body to great forces. Injury characteristics have not been systematically reviewed for these two growing sports.

OBJECTIVE

The purpose of this study was to systematically review the literature regarding various definitions of injuries used, injury localisation, the prevalence and incidence of injuries and the associated risk factors for injuries in weightlifting and powerlifting.

DESIGN

Systematic review.

DATA SOURCES

Five databases, PubMed, MEDLINE, SPORTDiscus, Scopus and Web of Science, were searched between 9 March and 6 April 2015.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies assessing injury incidence and prevalence in Olympic weightlifting and powerlifting were included. The Quality assessment tool for observational cohort and cross-sectional studies was used to assess methodological quality.

RESULTS

9 studies were included in the review. Injury was defined fairly consistently across studies. Most studies were of low methodological quality. The spine, shoulder and the knee were the most common injury localisations in both sports. The injury incidence in weightlifting was 2.4-3.3 injuries/1000 hours of training and 1.0-4.4 injuries/1000 hours of training in powerlifting. Only one retrospective study had analysed possible risk factors.

SUMMARY/CONCLUSIONS

The risk of injury in both sports were similar to other non-contact sports also requiring strength/power, but low compared to contact sports. The severity of injuries differed in the included studies. Since little has been studied regarding possible risk factors to injuries, further research is therefore warranted to explain why athletes get injured and how to prevent injuries.

TRIAL REGISTRATION NUMBER

PROSPERO CRD42015014805.

Shoulder Injuries in Individuals Who Participate in CrossFit Training

Background:

CrossFit, a sport and fitness program, has become increasingly popular both nationally and internationally. Researchers have recently identified significant improvements in health and wellness due to CrossFit. However, some individuals assert that CrossFit poses an inherent risk of injury, specifically to the shoulder, due to the intensity of training. Currently, there is limited evidence to support this assertion.

Hypothesis:

Exercises performed during CrossFit do not place the shoulder at greater risk for injury. Injury rates are comparable to other sports of similar intensity.

Study Design:

Descriptive survey study.

Level of Evidence:

Level 5.

Methods:

An electronic survey was developed and dispersed to approximately 980 individuals who trained in CrossFit gyms. The survey identified demographic data, training characteristics, and the prevalence of injury over a 6-month period in individuals who participated in CrossFit training.

Results:

A total of 187 (19.1%) individuals completed the survey. Forty-four (23.5%) indicated that they had experienced a shoulder injury during CrossFit training over the previous 6 months. Of those who reported injury, 17 (38.6%) stated that this injury was an exacerbation of a previous injury sustained prior to starting CrossFit. There was no significant relationship between several demographic and training variables and shoulder injury. All shoulder injuries occurred at a rate of 1.94 per 1000 hours training, while “new” shoulder injuries occurred at a rate of 1.18 per 1000 hours training. The most commonly attributed causes of injury were improper form (33.3%) and exacerbation of a previous injury (33.3%). Twenty-five (64.1%) of those who experienced injury reported 1 month or less of training reduction due to the injury.

Conclusion:

Shoulder injury rates during CrossFit training are comparable to other methods of recreational exercise.

Clinical Relevance:

Clinicians should be aware of training demands of exercises in CrossFit and modifications for these exercises to safely progress their patients back to participation.

Shoulder Joint and Muscle Characteristics Among Weight-Training Participants With and Without Impingement Syndrome

Kolber, MJ, Hanney, WJ, Cheatham, SW, Salamh, PA, Masaracchio, M, and Liu, X. Shoulder joint and muscle characteristics among weight-training participants with and without impingement syndrome. J Strength Cond Res 31(4): 1024-1032, 2017-Subacromial impingement syndrome (SIS) has been reported as an etiological source of shoulder pain among weight-training (WT) participants; however, a paucity of evidence exists to describe intrinsic risk factors. The purpose of this study was to investigate specific risk-related joint and muscle adaptations among WT participants identified as having SIS based on a previously validated clinical testing cluster. Fifty-five men (mean age 27.3 years) who participated in recreational WT a minimum of 2 d·wk were recruited, including 24 individuals with SIS and 31 without SIS serving as controls. Active range of motion (AROM), bodyweight-adjusted strength values, and strength ratios were compared between groups. Significant differences were present as WT participants with SIS had decreased internal and external rotation AROM (p ≤ 0.016) and decreased bodyweight-adjusted strength values of the external rotator and lower trapezius musculature (p ≤ 0.02) when compared with WT participants without SIS. Select strength ratios were greater in the SIS group (p ≤ 0.004) implying agonist to antagonist muscle imbalances. The impaired joint and muscle characteristics identified among WT participants with SIS are not without consequence, as they are associated with shoulder disorders in both general and athletic populations. Practical applications for these findings may reside in exercise prescription that addresses internal rotation mobility, mitigates training bias, and favors muscles responsible for stabilization, such as the external rotators and lower trapezius. Strength and conditioning professionals should consider risk-related adaptations associated with WT when prescribing upper-extremity exercises.

Shoulder Joint Position Sense in Injured and Noninjured Judo Athletes

Context:

A reduction in joint position sense (JPS) is sometimes a consequence of shoulder injury that may adversely affect the ability to maintain dynamic joint stability.

Objective:

To compare shoulder JPS between previously injured and noninjured judokas.

Design:

Cohort study.

Participants:

Twenty-nine noninjured subjects (10.93 ± 3.45 years) and eleven injured subjects (15.09 ± 3.39 years).

Main Outcome Measures:

JPS was tested at 45° and 80°of shoulder external rotation at 90° of abduction.

Results:

No signifcant difference in JPS was found between previously injured and noninjured judokas at either joint position.

Conclusion:

Despite evidence that JPS acuity decreases following shoulder injury, this study did not demonstrate a difference in average error between previously injured and noninjured judokas. Uncontrolled confounding factors, such as age and time since injury, may have affected the results. Sport-specifc shoulder joint loading patterns may also be an important factor that affects JPS.

Characteristics of anterior shoulder instability and hyperlaxity in the weight-training population

Despite case reports implicating anterior instability (AI) as an etiological source of shoulder pain among weight-training (WT) participants, a paucity of case-controlled evidence exists to support this premise. The purpose of this study was to determine if WT participants have clinical characteristics of AI and hyperlaxity. Additionally, we investigated the role of exercise selection. One hundred fifty-nine healthy male participants (mean age 28 years) were recruited and included 123 individuals who engaged in WT a minimum of 2 days per week and 36 controls with no history of WT participation. Before testing, participants completed a questionnaire summarizing their training patterns. Upon completing the questionnaire, 3 reliable and valid tests used to identify clinical characteristics of AI were performed on both groups and included the load and shift, apprehension, and relocation maneuvers. Load and shift test results identified significantly greater anterior glenohumeral joint hyperlaxity in the WT group compared with controls (p = 0.004). The presence of positive apprehension (p < 0.001) and relocation (p < 0.001) tests were also significantly greater in the WT group. A significant association existed between performance of exercises that require the "high-five" position (behind-the-neck latissimus pull-downs and military press) and clinical characteristics of AI. Conversely, an inverse association between performance of external rotator strengthening and clinical characteristics of AI existed. Findings from this study suggest that individuals participating in WT may be predisposed to AI and hyperlaxity. Modification of exercises requiring the high-five position, as well as efforts to strengthen the external rotators, may serve as a useful means to mitigate characteristics associated with AI and hyperlaxity. Future intervention-based trials are needed to investigate a causative effect of exercises.

Shoulder joint and muscle characteristics among healthy female recreational weight training participants

Shoulder disorders attributed to weight training are well documented in the literature, with prevalence rates exceeding that of the general population. Although researchers have identified both intrinsic and extrinsic risk factors among men who participate in weight training, a paucity of evidence-based research exists to describe risk factors inherent to participation among women. The purpose of this study was to investigate shoulder joint and muscle characteristics among healthy female recreational weight training (RWT) participants to determine specific risk-related adaptations that may occur from training. Eighty-eight women aged 18-55 (mean 26.8), including 57 who participated in upper extremity RWT and 31 controls with no record of RWT participation were recruited. Active range of motion (AROM), posterior shoulder tightness (PST), glenohumeral (GH) joint laxity, body weight-adjusted strength and strength ratios of force couples were compared between the RWT and control groups. Statistical analysis identified significant differences (p ≤ 0.004) between groups when analyzing shoulder internal rotation AROM, PST, and joint laxity. The RWT participants had decreased internal rotation AROM, greater PST, and anterior GH joint hyperlaxity when compared to the control group. No differences in strength ratios between groups were identified (p ≥ 0.109) implying the absence of weight training-induced muscle imbalances. The findings of this investigation suggest that female RWT participants are predisposed to mobility imbalances as a result of training. The imbalances identified in this investigation have been associated with shoulder disorders in both the general and athletic population thus may place weight training participants at risk for injury. Clinicians and strength and conditioning professionals should consider the biomechanical stresses and adaptations associated with RWT when prescribing exercises. Exercise prescription that mitigates mobility imbalances may serve to prevent injury in this population.

Shoulder injuries attributed to resistance training: a brief review

The popularity of resistance training (RT) is evident by the more than 45 million Americans who engage in strength training regularly. Although the health and fitness benefits ascribed to RT are generally agreed upon, participation is not without risk. Acute and chronic injuries attributed to RT have been cited in the epidemiological literature among both competitive and recreational participants. The shoulder complex in particular has been alluded to as one of the most prevalent regions of injury. The purpose of this manuscript is to present an overview of documented shoulder injuries among the RT population and where possible discern mechanisms of injury and risk factors. A literature search was conducted in the PUBMED, CINAHL, SPORTDiscus, and OVID databases to identify relevant articles for inclusion using combinations of key words: resistance training, shoulder, bodybuilding, weightlifting, shoulder injury, and shoulder disorder. The results of the review indicated that up to 36% of documented RT-related injuries and disorders occur at the shoulder complex. Trends that increased the likelihood of injury were identified and inclusive of intrinsic risk factors such as joint and muscle imbalances and extrinsic risk factors, namely, that of improper attention to exercise technique. A majority of the available research was retrospective in nature, consisting of surveys and descriptive epidemiological reports. A paucity of research was available to identify predictive variables leading to injury, suggesting the need for future prospective-based investigations.

Internal impingement: a review on a common cause of shoulder pain in throwers

Internal impingement is a term used to describe the pathologic contact of the undersurface of the rotator cuff with the glenoid. It typically occurs in overhead athletes, particularly throwers. In these athletes, the bones and soft tissues adapt to allow these athletes to have a supraphysiologic range of motion. In many athletes, these changes may lead to symptoms of internal impingement. This article discusses the background, biomechanics, pathophysiology, clinical and radiographic assessment, treatments, and outcomes of this disorder.

Internal impingement of the shoulder in the overhead athlete

Internal impingement of the shoulder refers to a constellation of pathologic conditions, including, but not limited to, articular-sided rotator cuff tears, labral tears, biceps tendinitis, anterior instability, internal rotation deficit, and scapular dysfunction. Physiologic adaptations to throwing include increased external rotation, increased humeral and glenoid retroversion, and anterior laxity, all of which may predispose an individual to internal impingement. Nonoperative treatment should always be attempted first, with a focus on increasing the range of motion and improving scapular function. When an operative intervention is chosen, it is important to address microinstability in order to have a good outcome and prevent failure.

Comparison of chain- and plate-loaded bench press training on strength, joint pain, and muscle soreness in Division II baseball players

The purpose of this study was to investigate the effects of chain- (CBP) and plate-loaded (PBP) bench press training on measures of strength, shoulder pain, and muscle soreness in Division II baseball players. Twenty-eight subjects with previous resistance training experience (4.8 +/- 2.7 years) completed the study while participating in off-season baseball practice. All subjects completed a one-repetition maximum pre- and posttest on the CBP and PBP and reported shoulder pain and muscle soreness on 15 occasions during training. Two treatment groups, CBP and PBP, trained 2 d.wk for 9 weeks during the off-season with a linear periodization strength training program. The CBP group used chains attached to the bar as the entire load, and the PBP group used only traditional plate-loaded resistance. The chains provided a variable resistance, with a reduction in load during the descent as the weight collected on the floor and with the load increasing during ascent as the weight was lifted from the floor. Statistically significant increases were found in strength scores after training for the CBP test (p < 0.001) and the PBP test (p < 0.001). Both groups were able to improve strength on the CBP and PBP, but no significant differences were found in strength gains between the groups on the CBP and PBP tests. Although levels of pain and soreness were not significantly different, a threefold difference was found for perceived levels of shoulder pain (mean totals of 2.15 vs. 6.14), whereas reported soreness was similar (9.38 vs. 10.57) for the CBP and PBP group, respectively. The data indicate that training with chain- and plate-loaded resistance produce similar short-term strength improvement on the chain- and plate-loaded bench press. Baseball players may benefit from CBP training with improved free-weight strength while minimizing shoulder stress.

Shoulder joint and muscle characteristics in the recreational weight training population

Shoulder disorders attributed to weight training are well documented in the literature; however, a paucity of evidence-based research exists to describe risk factors inherent to participation. Shoulder joint and muscle characteristics in the recreational weight training (RWT) population were investigated to determine specific risk-related adaptations that may occur from participation. Ninety participants, men between the ages of 19 and 47 (mean age 28.9), including 60 individuals who participated in upper-extremity RWT and 30 controls with no record of RWT participation, were recruited. Active range of motion (AROM), posterior shoulder tightness (PST), body weight-adjusted strength values, and agonist/antagonist strength ratios were compared between the RWT participants and the control group. Statistical analysis identified significant differences (p < 0.001) between the groups when analyzing shoulder mobility. The RWT 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 RWT group when compared with the control group (p <or= 0.001), implying agonist/antagonist muscle imbalances. The findings of this investigation suggest that RWT participants are predisposed to strength and mobility imbalances as a result of training. The imbalances identified have been associated with shoulder disorders in the general and athletic population; thus, these imbalances may place RWT participants at risk for injury. Common training patterns are biased toward large muscle groups such as the pectorals and deltoids but neglect muscles responsible for stabilization such as the external rotators and lower trapezius. Exercise selection that mitigates strength and mobility imbalances may serve to prevent injury in this population. Clinicians and strength and conditioning professionals should consider the biomechanical stresses and adaptations associated with RWT when prescribing upper-extremity exercises.

Débridement of small partial-thickness rotator cuff tears in elite overhead throwers

Elite overhead throwing athletes with rotator cuff tears represent a unique group of patients with an ultimate goal of returning to their previous level of competition. We hypothesized débridement of small partial-thickness rotator cuff tears would return the majority of elite overhead throwing athletes to their previous level of competition. Preoperative and intraoperative findings on 82 professional pitchers who had undergone débridement of partial-thickness rotator cuff tears were evaluated using our database. We obtained return to play data on 67 of the 82 players (82%); 51 (76%) were able to return to competitive pitching at the professional level and 37 (55%) were able to return to the same or higher level of competition. Of the 67 patients, 34 pitchers returned a questionnaire with a minimum followup of 18 months (mean 38 months; range 18 to 59 months). SF-12 scores were above average with a mean PSF-12 and MSF-12 of 55.04 and 56.49 respectively. An Athletic Shoulder Outcome Rating Scale score of greater than 60 was found in 76.5% of pitchers. Débridement of small partial-thickness rotator cuff tears allowed a majority of elite overhead throwing athletes to return to competitive pitching, however, returning to their previous level of competition remains a challenge for many of these players.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

The effectiveness of rehabilitation for nonoperative management of shoulder instability: a systematic review

A systematic review of published evidence on conservative management was conducted in Medline, Cumulative Index to Nursing & Allied Health Literature (CINAHL), Database of Abstracts of Reviews of Effects (DARE), Allied & Alternative Medicine (AMED), PubMed, and Cochrane. For each article, two of the four reviewers conducted abstract selection and critical appraisal. Disagreements were resolved through consensus and third review, if required. Level of evidence and quality on a 24-item quantitative critical appraisal form were determined for all articles meeting selection criteria. Outcomes considered included recurrence of instability and return to premorbid function. Overall, the quantity and quality of evidence were low. Immobilization for three to four weeks followed by a structured 12-week rehabilitation program of range of motion and glenohumeral and scapular stability exercises for patients with primary dislocations to maximize return to premorbid activity level is supported by weak evidence. Level II evidence suggests that recurrence is lower in patients managed with surgical as compared with conservative management. Further research is required to delineate the optimal approach to rehabilitation and its role in secondary prevention.

Injury incidence and prevalence among elite weight and power lifters

The purpose of this study was to investigate the incidence and prevalence of injuries among elite weight lifters and power lifters, with a special focus on shoulder injuries and possible injury-provoking exercises. In 1995, a questionnaire was administered to 110 male and female elite lifters to evaluate injuries and training characteristics. A follow-up of the athletes from 1995 was conducted in 2000, and a new 2000 elite group was also queried. In 1995 and again in 2000, the athletes sustained, on average, 2.6 injuries per 1000 hours of activity. Most common in 1995 were low back injuries, with an injury rate of 0.43 per 1000 hours, and shoulder injuries, with a rate of 0.42 per 1000 hours. Shoulder injuries dominated in 2000, with an injury rate of 0.51 per 1000 hours of activity. There was a difference in injury pattern between weight lifters, who mostly sustained low back and knee injuries, and power lifters, in whom shoulder injuries were most common. No correlation was found between shoulder injuries and any specific exercise. Although the total injury rate was the same during the two periods of study, the rate of shoulder injuries had increased.

Bilateral anterior shoulder dislocation in a weight lifter

A young man experienced bilateral anterior dislocation of the shoulders while doing seated behind-the-neck military presses. When improperly performed, military presses can cause injury because the shoulder muscles may be unable to support the weight being lifted. To improve form, avoid injury, and maximize gain from workouts, beginning weight lifters and those with shoulder instability should be counseled to use safer alternative techniques such as frontal military presses that do not allow movement posterior to the plane of the body.

Injuries to the shoulder in the throwing athlete. Part one: Biomechanics/pathophysiology/classification of injury

Over the last decade, significant advances have been made in the study and understanding of shoulder mechanics. Much of this may be attributed to the use of more sophisticated technology to improve our ability to assess the shoulder in real-time athletics. As a consequence of these advances, our understanding of the pathophysiology of injury has also increased. Our manual examination skills have improved and our noninvasive diagnostic techniques have advanced greatly. New insight into forces at play during actions as complex as the throwing motion has allowed us to develop better protocols for the prevention and treatment of the most common injuries. Additionally, paralleling improvements in the understanding of shoulder kinematics and the pathophysiology of injury, advances in surgical techniques, particularly arthroscopy, have aided in the diagnosis of and the development of less invasive surgical treatments for injuries that do not respond to nonoperative measures. Undoubtedly, an up-to-date understanding of the developments in shoulder biomechanics, pathophysiology of injury, diagnostic techniques, and surgical management is necessary for the clinician who wishes to continue to apply proper skills in the sports medicine setting.

Upper extremity weight-training modifications for the injured athlete. A clinical perspective

The ability of the health care professional to make correct decisions about the progression of weight-training is critical to the rehabilitation process. The purpose of this article is to describe our approach to modification of weight-lifting techniques using the injured shoulder as a model. Additionally, the impact of various upper extremity weight-training techniques on healthy athletes is discussed. The effects of grip, hand spacing, bar trajectory, and start and finishing positions on microtraumatic injury and return to weight-training activities after injury are considered. Several weight-training functional progressions for common multijoint exercises (such as bench press, shoulder press, power clean) are presented. Adaptations for periodization are also presented for implementation in the rehabilitation sequence. The weight-training modifications described in this paper will assist the health professional to safely return athletes to the weight room after shoulder injury.

Weight training injuries: part 1: diagnosing and managing acute conditions

When patients present with acute weight training injuries, familiarity with the demands of the activity can help physicians get the most out of the patient history. Probable risk factors for injury include errors in technique (described in a sidebar), skeletal immaturity, and anabolic steroid abuse. Common acute injuries in weight training include sprains, strains, tendon avulsions, and compartment syndrome. Possible nonmusculoskeletal problems include retinal hemorrhage, radiculopathy, and various cardiovascular complications. Treatment of acute musculoskeletal injuries varies, but usually includes sports medicine mainstays such as prompt RICE. Chronic weight training injuries will be described in part 2 of this series.

Anterior release test. A new test for occult shoulder instability

Occult shoulder instability is recognized as a significant contributor to shoulder dysfunction in throwing athletes. Diagnosis of occult instability by physical examination remains challenging. The anterior release test is a test for physical examination of the shoulder. It was developed to facilitate detection of occult anterior instability. One hundred shoulders were examined preoperatively by the same examiner. Based on surgical findings, the shoulders were classified as anterior instability or other. The results of examination were compared with the operative findings. Sensitivity was calculated as 91.9%, specificity 88.9%, positive predictive value 87.1%, negative predictive value 93.0%, and accuracy 90.2%. The anterior release test is a reliable and reproducible test for the detection of the unstable shoulder.