Humeral Torsion in Relation to Shoulder Range of Motion in Elite Field Hockey Players.

CONTEXT: Sport-specific adaptations in shoulder rotation range of motion (ROM) and the relationship with humeral torsion have been described in overhead-throwing sports. However, information is lacking for other shoulder-loading sports such as field hockey. Therefore, this study's purpose was to evaluate humeral torsion in elite, male field hockey players and explore its association with shoulder ROM. DESIGN: Cross-sectional study. METHODS: Twenty-five male, elite field hockey players were included. Humeral torsion and shoulder external and internal rotation ROM were evaluated bilaterally by ultrasound and an inclinometer smartphone application, respectively. RESULTS: Field hockey players showed a significantly increased humeral retroversion on the dominant compared with the nondominant side (P < .001; Cohen d = 1.75), along with a significantly increased external (P = .004; Cohen d = -0.64) and decreased internal rotation ROM (P = .003; Cohen d = 0.65). This finding illustrates a shift in total shoulder rotational ROM arc. Correlation analysis showed a significant moderate association between the increased humeral retroversion and decreased internal rotation ROM on the dominant side (r = .523). CONCLUSIONS: Elite male field hockey athletes show sport-specific adaptations regarding humeral torsion and shoulder rotation ROM, similar to throwing athletes. These findings increase our insight into the field hockey athlete's shoulder, which is essential to optimize performance and assist in correctly interpreting shoulder rotational ROM measurements.

Scapulothoracic muscle activity during kinetic chain variations of a prone elevation exercise.

BACKGROUND: Scapular rehabilitation exercises should target appropriate muscles. Recently, adding external rotation resistance to scapular exercises has gained interest. Moreover, clinical experts advise kinetic chain integration into shoulder rehabilitation exercises. OBJECTIVE: To investigate scapular muscle activity during kinetic chain variations of a prone elevation exercise. METHODS: Activity of the upper (UT), middle (MT), and lower (LT) trapezius and serratus anterior (SA) muscles was determined with surface electromyography (EMG) in 31 asymptomatic participants during six prone elevation exercise variations. Variation was created by adding external rotation resistance, adding trunk extension, or changing exercise position (prone on a Swiss ball with knees or feet supported, or prone on a physiotable). All data were normalized as a percentage of maximal voluntary isometric contraction (% MVIC). For each muscle, a Friedman's ANOVA was conducted to analyse statistical differences in EMG signal intensity between exercises. RESULTS: The LT was moderately (42 - 48% MVIC) and MT highly (63 - 66% MVIC) activated during all exercise variations. No significant differences between exercises for these muscles could be detected. Adding external rotation to a prone elevation exercise decreased UT activity while adding trunk extension increased UT activity. Altering exercise position had no influence on scapular muscle activity except increased UT activity when lying prone on a physiotable with trunk extension. CONCLUSION: Prone elevation exercises are appropriate for facilitating LT and MT activity. Adding external rotation inhibits UT activity while UT facilitation could be achieved when adding trunk extension.

The challenge of the sporting shoulder: From injury prevention through sport-specific rehabilitation toward return to play.

Shoulder injuries and sports-related shoulder pain are substantial burdens for athletes performing a shoulder loading sport. The burden of shoulder problems in the athletic population highlights the need for prevention strategies, effective rehabilitation programs, and a individually based return-to-play (RTP) decision. The purpose of this clinical commentary is to discuss each of these 3 challenges in the sporting shoulder, to assist the professional in: (1) preventing injury; (2) providing evidence-based practice rehabilitation and; (3) to guide the athlete toward RTP. The challenges for injury prevention may be found in the search for (the interaction between) relevant risk factors, develop valid screening tests, and implement feasible injury prevention programmes with maximal adherence from the athletes. Combined analytical and functional testing seems mandatory screening an athlete's performance. Many questions arise when rehabilitating the overhead athlete, from exercise selection, over the value of stretching, toward kinetic chain implementation and progression to high performance training. Evidence-based practice should be driven by the available research, clinical expertise and the patient's expectations. Deciding when to return to sport after a shoulder injury is complex and multifactorial. The main concern in the RTP decision is to minimize the risk of re-injury. In the absence of a "gold standard", clinicians may rely on general guidelines, based on expert opinion, regarding cutoff values for normal range of motion, strength and function, with attention to risk tolerance and load management.

The effect of five isometric exercises on glenohumeral translations in healthy subjects and patients with the hypermobility type of the ehlers-danlos syndrome (heds) or hypermobility spectrum disorder (hsd) with multidirectional shoulder instability: an observational study.

OBJECTIVES: To examine whether patients, diagnosed with the hypermobility type of the Ehlers-Danlos syndrome (hEDS) or Hypermobility Spectrum Disorder (HSD), with multidirectional shoulder instability (MDI) have increased humeral head translations compared to healthy controls and to describe the direction of the humeral translations during five exercises. DESIGN: Observational study. SETTING: Ghent University Hospital. PARTICIPANTS: Twenty-seven female patients (aged mean (SD) 35 (13) years) with hEDS/HSD and MDI and 20 female healthy controls (aged 34 (11) years) participated in this study. INTERVENTIONS: The acromiohumeral (AHD) and humeralglenoid distance (HGD) were measured using ultrasound during five isometric exercises: shoulder external rotation, shoulder extension, shoulder flexion, elbow extension and holding a 2kg dumbbell. MAIN OUTCOME MEASURES: Ultrasound measures of the AHD and HGD. RESULTS: During isometric shoulder extension, elbow extension and dumbbell loading, patients had a significantly larger change in AHD compared to controls. In patients, the AHD was significantly smaller during isometric shoulder flexion, extension and elbow extension compared to the AHD measured in rest. By contrast, the AHD was significantly larger during isometric external rotation and dumbbell loading compared to the AHD measured in rest. Regarding the HGD, no significant differences between patients and controls were observed. However, significantly smaller HGD values were found in patients during isometric shoulder flexion compared to the HGD in rest. CONCLUSIONS: Isometric external rotation and holding a 2kg dumbbell caused an inferior translation in patients with hEDS/HSD and MDI, whereas isometric shoulder flexion and shoulder/elbow extension respectively led to an anterior-superior and superior translation.

Relative Scapular-Muscle Ratios During Maximal Isokinetic Shoulder-Girdle Strength Performance in Elite Field Hockey Players.

CONTEXT: The shoulder joint and girdle are highly loaded during field hockey play. To optimize performance and to better substantiate preventive programs, it is important to gain insight into shoulder-girdle muscle function and balance in this athlete population. OBJECTIVE: To evaluate relative scapular muscle-activity ratios through surface electromyography during maximal isokinetic strength testing in elite male field hockey players compared with nonathletes. DESIGN: Cross-sectional study. SETTING: Institutional laboratory. PATIENTS OR OTHER PARTICIPANTS: Twenty-five elite field hockey players from the Belgian National Team and 25 age- and sex-matched nonathletes. INTERVENTION(S): We measured bilateral activity in 4 scapular muscles (upper trapezius [UT], middle trapezius [MT], lower trapezius [LT], and serratus anterior [SA]) during an external-internal rotation and protraction-retraction isokinetic shoulder protocol. MAIN OUTCOME MEASURE(S): Relative scapular muscle-activity ratios, or balance ratios, of the UT : MT, UT : LT, UT : SA, SA : MT, and SA : LT. RESULTS: We noted lower ratios bilaterally in the athlete group compared with the control group for the UT : MT, UT : LT, and SA : MT ratios during protraction, retraction, and external rotation, respectively, and unilaterally (dominant side only) for the UT : LT ratio during protraction. No consistent trend was present for established side differences in the studied balance ratios. CONCLUSIONS: Compared with nonathletes, elite field hockey players had altered intramuscular (within the trapezius) and intermuscular (between the trapezius and SA) balance ratios during maximal shoulder-girdle contractions, with relatively more MT and LT activity. This may reflect a sport-specific adaptation to optimize coordinated activity of the scapulothoracic muscles, meeting the specific demands of field hockey movements and simultaneously better protecting the shoulder against injury. Our results can assist in optimizing high-performance training and in supporting injury-prevention programs, which are key to both successful and long-lasting athletic careers.

Quantifying acromiohumeral distance in elite male field hockey players compared to a non-athletic population.

BACKGROUND: Shoulders of elite field hockey players are loaded continuously during play. Frequent high shoulder loading is known to influence certain shoulder variables, such as acromiohumeral distance. However, the influence of elite field hockey play on acromiohumeral distance is not examined yet. OBJECTIVE: To examine the acromiohumeral distance in elite male field hockey players compared to a non-athletic control group. DESIGN: Cross-sectional study. METHODS: Fifty male participants were included; 25 elite field hockey players (age: 24.0±2.72 years; weight: 77.2±5.29kg; height; 180.5±5.37cm) and 25 age- and gender matched non-athletes (23.0±2.29 years; weight: 75.7±9.53kg; height: 181.8±5.52cm). A Telemed-Colormaster-128 EXT-IZ device was used to bilaterally obtain ultrasound acromiohumeral distance images at 3 different angles of shoulder abduction in the frontal plane. RESULTS: Field hockey players showed a bilateral larger acromiohumeral distance at 45° (mean difference: 1.46mm [95% CI 0.46; 2.46]; p=0.005) and 60° (mean difference: 1.07mm [95% CI 0.21; 1.93]; p=0.016) compared to controls. In both groups, a significant but clinically less relevant, side difference was established for the acromiohumeral distance at 60° (mean difference: 0.79mm [95% CI 0.21; 1.34]; p=0.009). CONCLUSION: With active shoulder abduction, elite field hockey players show a larger acromiohumeral distance in comparison to non-athletic participants. This may be a protective sport-specific adaptation, to better guard the shoulder from injury. Thus, acromiohumeral distance measurement may help physical therapists/coaches decide which athletes could benefit from specific, additional exercises aimed at enlarging the subacromial space.

Elite male field hockey players have symmetric isokinetic glenohumeral strength profiles, but show asymmetry in scapular muscle strength.

Shoulders of elite field hockey players are loaded continuously during play. However, shoulder girdle muscle performance in this population has never been examined yet. This study aimed to compare isokinetic shoulder girdle performance in elite male field hockey players to matched controls, with respect to strength, endurance and muscle balance. The complete male national field hockey team of Belgium (n = 25) was included and matched to a gender- and age-matched control group of healthy participants (n = 25). A Biodex system-4 dynamometer was used to measure glenohumeral and scapular muscle strength at 2 velocities in a concentric/concentric mode. With the main outcome measures being isokinetic strength values, peak force (protraction-retraction), peak torque (rotations), fatigue index and agonist/antagonist ratio's. Measurement results showed that elite male field hockey players were stronger than their matched controls, for both the rotational and the protraction-retraction movement. Concerning rotational strength, symmetrical findings were established, contrary to scapular strength, where side differences were noted. At low velocity, retraction peak force was higher on the dominant side. Protraction peak force was higher on the non-dominant side when measured at high velocity. In conclusion, elite field hockey players have a symmetrical rotational strength profile, in contrast to their scapular strength profile.

Eccentric and isometric shoulder rotator cuff strength testing using a hand-held dynamometer: reference values for overhead athletes.

PURPOSE: In order to provide science-based guidelines for injury prevention or return to play, regular measurement of isometric and eccentric internal (IR) and external (ER) rotator strength is warranted in overhead athletes. However, up to date, no normative database exists regarding these values, when measured with a hand-held dynamometer. Therefore, the purpose of the study was to provide a normative database on isometric and eccentric rotator cuff (RC) strength values in a sample of overhead athletes, and to discuss gender, age and sports differences. METHODS: A HHD was used to measure RC strength in 201 overhead athletes between 18 and 50 years old from three different sports disciplines: tennis, volleyball and handball. Isometric as well as eccentric strength was measured in different shoulder positions. Outcome variables of interest were isometric ER and IR strength, eccentric ER strength, and intermuscular strength ratios ER/IR. RESULTS: Our results show significant side, gender and sports discipline differences in the isometric and eccentric RC strength. However, when normalized to body weight, gender differences often are absent. In general, strength differences are in favour of the dominant side, the male athletes and handball. Intermuscular ER/IR ratios showed gender, sports, and side differences. CONCLUSION: This normative database is necessary to help the clinician in the evaluation of RC strength in healthy and injured overhead athletes. In view of the preventive screening and return-to-play decisions in overhead athletes, normalization to body weight and calculating intermuscular ratios are key points in this evaluation. LEVEL OF EVIDENCE: Diagnostic study, Level III.

Evidence-based rehabilitation of athletes with glenohumeral instability.

PURPOSE: To give an overview of current knowledge and guidelines with respect to evidence-based rehabilitation of athletes with glenohumeral instability. METHODS: This narrative review combines scientific evidence with clinical guidelines based on the current literature to highlight the different components of the rehabilitation of glenohumeral instability. RESULTS: Depending on the specific characteristics of the instability pattern, the severity, recurrence, and direction, the therapeutic approach may be adapted to the needs and demands of the athlete. In general, attention should go to (1) restoration of rotator cuff strength and inter-muscular balance, focusing on the eccentric capacity of the external rotators, (2) normalization of rotational range of motion with special attention to the internal rotation ROM, (3) optimization of the flexibility and muscle performance of the scapular muscles, and (4) gradually increasing the functional sport-specific load on the shoulder girdle. The functional kinetic chain should be implemented throughout all stages of the rehabilitation program. Return to play should be based on subjective assessment as well as objective measurements of ROM, strength, and function. CONCLUSIONS: This paper summarizes evidence-based guidelines for treatment of glenohumeral instability. These guidelines may assist the clinician in the prevention and rehabilitation of the overhead athlete. LEVEL OF EVIDENCE: Expert opinion, Level V.