Flexibility, Position, and Strength of the Shoulder Complex in Pediatric and Adult Amateur Tennis Athletes.

CONTEXT: Understanding the musculoskeletal adaptations in the shoulder complex of varying ages of tennis athletes may suggest preventive protocols and conditioning and rehabilitation programs to this population. This study aimed to generate a bilateral descriptive profile of shoulder flexibility, scapular and clavicular position, and muscle strength in pediatric and adult amateur tennis athletes. The outcome measures were compared between groups and sides. The number and percentage of athletes "at risk" according to cutoff values for shoulder range of motion (ROM) were also analyzed. DESIGN: Cross-sectional study. METHODS: 36 pediatric and 28 adult amateur tennis athletes were tested. Outcome measures were ROM of shoulder flexion, abduction, internal and external rotation, posterior capsule tightness, pectoralis minor index (PMI), scapular upward rotation, clavicular elevation, and strength of the external rotators, serratus anterior, and lower trapezius of the dominant/nondominant sides. RESULTS: Pediatric athletes had greater dominant side external rotation (P = .01) and total ROM (P = .04), increased Low Flexion test (P = .01), and decreased PMI (P = .01) compared with the adults. Bilaterally, the pediatric athletes had greater dominant side external rotation ROM (P < .01) and decreased PMI (P = .002) as compared with their nondominant side, whereas the adults displayed lower values on posterior capsule tightness (P = .01) and decreased PMI (P = .02) on their dominant side compared with their nondominant side. For the remaining outcomes, no interaction effects were observed. The cutoff values for shoulder ROM showed that several athletes were "at risk" of shoulder problems. CONCLUSION: Upper extremity adaptations at the shoulder are present in both pediatric and adult tennis athletes. These data can assist clinicians in better understanding the biomechanical adaptations in the shoulder of amateur tennis athletes in different age groups.

Short-Term Effects of Thoracic Spine Manipulation on Shoulder Impingement Syndrome: A Randomized Controlled Trial.

OBJECTIVE: To investigate the short-term effects of thoracic spine manipulation (TSM) on pain, function, scapular kinematics, and scapular muscle activity in individuals with shoulder impingement syndrome. DESIGN: Randomized controlled trial with blinded assessor and patient. SETTING: Laboratory. PARTICIPANTS: Patients with shoulder impingement syndrome (N=61). INTERVENTIONS: Participants were randomly allocated to TSM group (n=30) or sham-TSM group (n=31) and attended 2 intervention sessions over a 1-week period. MAIN OUTCOME MEASURES: Scapular kinematics and muscle activity were measured at day 1 (baseline, before the first intervention), day 2 preintervention (before second intervention), day 2 postintervention (after the second intervention), and day 3 (follow-up). Shoulder pain and function were assessed by the Disability of the Arm, Shoulder and Hand questionnaire and Western Ontario Rotator Cuff Index at baseline, day 2 preintervention, and follow-up. An assessor blinded to group assignment measured all outcomes. RESULTS: Pain decreased by 0.7 points (95% confidence interval, 1.3-0.1 points) at day 2 preintervention and 0.9 points (95% confidence interval, 1.5-0.3 points) at day 2 postintervention in the TSM group. The Disability of the Arm, Shoulder and Hand questionnaire (P=.01) and Western Ontario Rotator Cuff Index (P=.02) scores improved in both groups. Scapular upward rotation increased during arm lowering (P<.01) at day 2 postintervention (5.3°) and follow-up (3.5°) in the TSM group. Upper trapezius activity increased (P<.05) in the sham-TSM group. Middle trapezius, lower trapezius, and serratus anterior decreased activities in both groups during elevation and lowering of the arm. CONCLUSIONS: TSM may increase scapular upward rotation during arm lowering. TSM does not seem to influence activity of the scapular muscles. The results concerning shoulder pain, function, scapular tilt, and internal rotation are not conclusive.

Effects of a stretching protocol for the pectoralis minor on muscle length, function, and scapular kinematics in individuals with and without shoulder pain.

STUDY DESIGN: Parallel-group intervention with repeated measures. INTRODUCTION: Shortening of the pectoralis minor (PM) may contribute to alterations in scapular kinematics. PURPOSE OF THE STUDY: To evaluate the effects of a stretching protocol on function, muscle length, and scapular kinematics in subjects with and without shoulder pain. METHODS: A sample of 25 patients with shoulder pain and 25 healthy subjects with PM tightness performed a daily stretching protocol for 6 weeks. Outcome measures included Disabilities of the Arm, Shoulder, and Hand questionnaire, PM length, and scapular kinematics. RESULTS: Disabilities of the Arm, Shoulder, and Hand scores decreased (P < .05) in the patient group at post-intervention. No differences (P > .05) were found for PM length in both groups. Scapular anterior tilt increased (P < .05) at 90° of flexion in the healthy group. DISCUSSION: This study demonstrated that a daily home stretching protocol significantly decreases pain and improves function in subjects with shoulder pain. The mechanism responsible for these improvements does not appear directly related to PM muscle length or scapula kinematics, suggesting that other neuromuscular mechanisms are involved. CONCLUSION: The PM stretching protocol did not change the PM length or scapular kinematics in subjects with or without shoulder pain. However, pain and function of the upper limbs improved in patients with shoulder pain. LEVEL OF EVIDENCE: 2b.

Presence of Latent Myofascial Trigger Points and Determination of Pressure Pain Thresholds of the Shoulder Girdle in Healthy Children and Young Adults: A Cross-sectional Study.

OBJECTIVE: The primary objective of this study was to compare the number of myofascial trigger points (MTPs) and the pressure pain thresholds (PPTs) in the shoulder girdle, on the dominant and nondominant sides, between healthy children and adults. The secondary aim was to assess the correlations between the number of MTPs and the PPTs in these populations. METHODS: A cross-sectional study was performed. Thirty-five children (aged 9.1 ± 1.7 years) and 35 adults (aged 23.4 ± 3.4 years) with no history of shoulder or cervical pathology were included. All participants were examined for MTPs in the shoulder muscles and assessed for PPTs in the neck, shoulder, and tibialis anterior. Parametric and nonparametric tests, effect sizes, and odds ratios were used to determine the differences between groups and sides. Spearman's σ test was used to assess correlations between latent MTPs (LTPs) and PPTs in each group. RESULTS: Children had fewer LTPs than adults did (P = .03). The upper trapezius was the muscle with the largest number of LTPs, affecting 13 adults on the dominant side. Children had lower PPTs compared with adults (P < .05). Correlations between the number of LTPs (on both sides and in total) and PPTs were observed only in adults. CONCLUSIONS: Healthy children have fewer LTPs and lower PPTs in the shoulder girdle than healthy adults. A relationship was observed between sensitivity to pressure and the presence of LTPs in adults, in whom lower PPT was associated with more LTPs. This relationship was not detected in children.

Effect of seated thoracic manipulation on changes in scapular kinematics and scapulohumeral rhythm in young asymptomatic participants: a randomized study.

OBJECTIVE: The purpose of this study was to evaluate the immediate effects of seated thoracic manipulation on scapulothoracic kinematics and scapulohumeral rhythm during arm flexion in young asymptomatic participants. METHODS: A convenience sample of 42 young asymptomatic participants was randomly divided in 2 groups: manipulation and sham group. Measurements were taken before and after the intervention. All participants completed the Disabilities of the Arm, Shoulder, and Hand questionnaire to assess pain and physical function. The manipulation group received the manipulation (high velocity, low amplitude), which was performed by a physical therapist with the patient in the seated position and with the arms crossed over the chest and hands passed over the shoulders. For the sham group, the same procedure was performed, with the exception that the high-velocity thrust was not applied. Three-dimensional (3D) kinematic data were collected with the participants in a relaxed standing position using a 3D electromagnetic tracking system. All participants performed 3 repetitions of arm flexion before and after manipulation. RESULTS: There were no differences (P = .79) in Disabilities of the Arm, Shoulder, and Hand scores when the manipulation (3.37 ± 3.72) was compared with the sham group (3.68 ± 4.27). The 3-way analysis of variance showed no significant interaction among group, angle, and time differences for the outcomes (scapulothoracic internal/external rotation [F = 0.43; P = .82], upward/downward rotation [F = 0.08; P = .99], tilt [F = 0.23; P = .94], and scapulohumeral rhythm [F = 4; P = .86]). The intragroup effect was small for the outcomes measured in both groups. CONCLUSIONS: Thoracic manipulation in the seated position did not affect scapulohumeral rhythm and 3D scapular kinematics during arm flexion in young asymptomatic participants.

Cervical sensitivity, range of motion and strength in individuals with shoulder pain: A cross-sectional case control study.

OBJECTIVES: To assess whether cervical sensitivity, range of motion (ROM) and strength are impaired in individuals with shoulder pain and how they interact with sociodemographic and clinical data. METHODS: Forty-eight individuals with shoulder pain and 48 asymptomatic matched ones were included. Pressure pain thresholds (PPTs) in cervical region and tibialis anterior muscles, ROM of cervical flexion, extension, lateral flexions and rotations and cervical muscle strength of flexion, extension and lateral flexions were assessed. Between-groups comparisons and a logistic multiple regression model were performed. RESULTS: The symptomatic group showed lower and not meaningful PPTs in trapezius of the unaffected/unmatched side, both sternocleidomastoid muscles, and tibialis anterior and reduced ROM in cervical extension (MD = -9.00°) when compared to the asymptomatic group. No differences were identified in muscle strength. Reduced PPT of the trapezius and reduced cervical extension ROM together accounted for 40.2% of the variance of the chance of presenting shoulder pain. CONCLUSION: Individuals with shoulder pain have more, but not clinically relevant, cervical sensitivity and lower cervical extension than asymptomatic individuals. The lower the PPT of the upper trapezius and the cervical extension ROM, the higher was the chance to present shoulder pain. Regional interdependence between cervical spine and shoulder may explain cervical physical function alterations in shoulder pain.

Stability, performance and upper and lower extremities range of motion in elite beach handball athletes: A cross sectional study.

Although beach handball is a popular sport worldwide, information about the functional profile in elite athletes are lacking. This study generate a descriptive profile of stability, performance and upper and lower extremities ROM in elite beach handball athletes. Secondary proposals were to compare these outcome measures between sexes and sides, and to report the frequency of athletes "at risk" according to cutoff values for shoulder ROM and dynamic postural stability of the lower extremities. Twenty-eight (n = 16 males, 28.7 ± 5.3 years; n = 12 females, 27.5 ± 5.5 years) elite beach handball athletes were tested. Closed Kinetic Chain Upper Extremity Stability Test (CKCUEST), single hop test, modified Star Excursion Balance Test (mSEBT) and passive shoulder, hip and ankle dorsiflexion ROM were assessed. Male athletes presented greater reach distance in the anterior direction [P < .0001; Mean Difference (MD): 36%] and lower reach distance in the posteromedial direction (P < .0001; MD: -29.7%) than female athletes in the mSEBT. Bilateral differences were observed for male athletes during the mSEBT, with the dominant stance limb obtaining a smaller reach distance in the anterior direction (P < .01; MD: -38.3%) and greater reach distance in the posteromedial direction (P < .0001; MD: 30.8%). Male athletes had less upper and lower extremities ROM and reached a smaller normalized single hop distance than female athletes. Most athletes presented mSEBT asymmetries and shoulder ROM deficits which have been shown to increase injury risk. Dynamic postural stability adaptations are present in elite beach handball athletes of both sexes, with more pronounced upper and lower extremity flexibility deficits in male athletes.

Is the Disabilities of the Arm, Shoulder and Hand (DASH) Questionnaire Adequate to Assess Individuals With Subacromial Pain Syndrome? Rasch Model and International Classification of Functioning, Disability and Health.

OBJECTIVE: The Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire is widely used to assess patients with symptoms of subacromial pain syndrome (SPS). No study has analyzed the DASH by using the Rasch model in these patients and related the level of difficulty of the items with the International Classification of Functioning Disability and Health (ICF) domains. The purpose of this study was to evaluate the measurement properties of the DASH in individuals with SPS and to describe which ICF components are influenced by SPS based on the DASH. METHODS: The full version of the DASH was used to assess upper limb pain and function in individuals with SPS. Responses were assessed using the Rasch model. DASH items were grouped according to the level of difficulty and associated with the ICF domains to identify the most compromised aspect in these individuals. RESULTS: Reliability and internal consistency for the DASH were shown to be 0.93 and 0.95, respectively. Item 3 ("Turn a key") was the easiest and 25 ("Pain during specific activity") the most difficult. Only item 30 ("Less capable/confident/useful") was as an erratic item. Item 15 ("Put on a sweater") showed differential functioning by age and item 11 ("Carry a heavy object") by sex. Seven items showed differential functioning related to the angular onset of pain during arm elevation. Sixty percent of the most difficult items belonged to the "Body function" domain of the ICF. CONCLUSION: Although some psychometric properties of the DASH are adequate according to the Rasch model, adjustments to some items are necessary for individuals with SPS. Clinicians should be cautious when interpreting the DASH, especially in patients with angular onset of pain above 120 degrees of arm elevation. IMPACT: The information contained in this study should be used by clinicians to interpret the results of the DASH when assessing individuals with SPS. The DASH may not be adequate to assess those with shoulder pain above 120 degrees of arm elevation. These results are not generalizable to other shoulder pathologies.

Comparison of specific and non-specific treatment approaches for individuals with posterior capsule tightness and shoulder impingement symptoms: A randomized controlled trial.

BACKGROUND: Posterior capsule tightness (PCT) is associated with shoulder pain and altered shoulder kinematics, range of motion (ROM), external rotation (ER) strength, and pain sensitization. OBJECTIVE: To assess the effects of two interventions on shoulder kinematics, Shoulder Pain and Disability Index (SPADI) scores, ROM, strength, and pressure pain threshold (PPT) in individuals with PCT and shoulder impingement symptoms. METHODS: In this prospectively registered randomized controlled trial 59 individuals were randomized to either an Experimental Intervention Group (EIG, n=31) or a Control Intervention Group (CIG, n=28). The low flexion (LF) test was used to determine the presence of PCT. Shoulder kinematics, SPADI scores, internal rotation (IR) and ER ROM, ER strength, and PPT were measured pre- and post-treatment. Those in the EIG received an intervention specific to pain and PCT and those in the CIG received a non-specific intervention, both 4 weeks in duration. RESULTS: Individuals in the EIG demonstrated more scapular upward rotation (P=.03; mean difference (MD)=3.3°; 95% Confidence Interval (CI)=1.3°, 4.9°) and improved value on the LF test (P=.02; MD=4.6°; 95%CI=0.7°, 8.6°) than those in the CIG after treatment. Both groups presented less anterior (P<.01; MD=-0.7mm; 95%CI=-1.3mm, -0.2mm) and superior (P<.01; MD=-0.5mm; 95%CI=-0.9mm, -0.2mm) humeral translations, decreased SPADI score (P<.01; MD=-23.6; 95%CI=-28.7, -18.4), increased IR ROM (P<.01; MD=4.6°; 95%CI=1.8°, 7.8°) and PPTs for upper trapezius (P<.01; MD=60.1kPa; 95%CI=29.3kPa, 90.9kPa), infraspinatus (P=.04; MD=47.3kPa; 95%CI=2.1kPa, 92.5kPa), supraspinatus (P<.01; MD=63.7kPa; 95%CI=29.6kPa, 97.9kPa), and deltoid (P<.01; MD=40.9kPa; 95%CI=12.3kPa, 69.4kPa) after treatment. CONCLUSION: The experimental intervention was more effective at improving PCT as measured through changes in the LF test. No benefit of the specific approach over the non-specific intervention was noted for the remaining variables.

Absolute and Relative Reliability of the Assessment of the Muscle Mechanical Properties of Pelvic Floor Muscles in Women with and without Urinary Incontinence.

An analysis of the muscle mechanical properties (MMPs) of the pelvic floor muscles (PFMs) is relevant for understanding the physiopathology of urinary incontinence (UI). However, there is no objective and reliable methodology currently available for quantifying the MMPs of PFMs. Thus, the objective was to determine the intra-rater and inter-rater reliability of the MMPs of PFM assessment with a hand-held tonometer device, called the MyotonPRO, in young women with and without UI. Sociodemographic and pelvic floor questionnaires, plus MMPs of PFMs were assessed in 38 nulliparous women with UI and 40 matched healthy women by two trained physiotherapists on two different occasions, 48-72 h apart. Good to excellent absolute reliability was found for tone, stiffness, and decrement of both intra- and inter-rater analyses in both study groups (Intraclass Correlation Coefficient ranged from 0.75 to 0.92), with a trend of lower values for relaxation and creep. The standard error of measurement (SEM) did not achieve 10% of the mean values for any MMPs. The minimum detectable change (MDC) values were also provided for clinical applications. In conclusion, the relative reliability of tone, stiffness, and the assessment of the decrement of PFMs with MyotonPRO is good to excellent for UI and healthy women. The SEM and MDC values were acceptable for their application in clinical settings.

DESCRIPTIVE PROFILE OF SHOULDER RANGE OF MOTION AND STRENGTH IN YOUTH ATHLETES PARTICIPATING IN OVERHEAD SPORTS.

BACKGROUND: The unilateral and repetitive nature of overhead sports, often result in a biomechanical overload of the upper extremity. Understanding the musculoskeletal shoulder range of motion (ROM) and strength patterns in the youth sports of baseball, softball, and tennis could assist injury prevention screening and further the development of conditioning and rehabilitation programs. PURPOSE: To generate a descriptive profile of shoulder musculoskeletal characteristics and determine whether bilateral differences in shoulder ROM exist in youth baseball, softball, and tennis athletes. A secondary aim was to determine whether shoulder rotational adaptations are correlated with playing position, sport, or years of experience. STUDY DESIGN: Descriptive Laboratory. METHODS: A total of 136 competitive youth overhead athletes (baseball: n = 51,12.8 ± 0.9yrs; softball: n = 63,12.3 ± 1.1yrs; and tennis: n = 22,12.5 ± 0.9yrs) participated. Bilateral shoulder internal (IR) and external (ER) passive ROM and external rotation strength were measured using an inclinometer and handheld dynamometer. RESULTS: Significant differences (p<.001) in bilateral shoulder ROM and ER strength were found between the athletes in the three sports. Post-hoc test revealed tennis athletes had greater bilateral shoulder ROM than both baseball and softball athletes, but baseball and softball athletes had greater bilateral ER strength than tennis athletes. There were no differences between baseball and softball athletes. Additionally, tennis athletes had greater bilateral internal rotation and total ROM but less ER strength than baseball pitchers, baseball positional athletes, softball pitchers, and softball positional athletes. There were no significant differences between positions and baseball and softball athletes. There were no significant correlations between playing position, sport, or years of experience. CONCLUSION: The results of this study showed differences in shoulder passive ROM and strength adaptations between youth tennis, baseball, and softball athletes. The descriptive nature of this study is impactful as it presents specific ROM adaptions seen in this population. Future research is needed to further evaluate if the "at risk" ROM identified in older populations holds true in the youth population. LEVEL OF EVIDENCE: Diagnosis, Level 3b.

Biopsychosocial Aspects in Individuals with Acute and Chronic Rotator Cuff Related Shoulder Pain: Classification Based on a Decision Tree Analysis.

Biopsychosocial aspects seem to influence the clinical condition of rotator cuff related shoulder pain (RCRSP). However, traditional bivariate and linear analyses may not be sufficiently robust to capture the complex relationships among these aspects. This study determined which biopsychosocial aspects would better classify individuals with acute and chronic RCRSP and described how these aspects interact to create biopsychosocial phenotypes in individuals with acute and chronic RCRSP. Individuals with acute (

Kinesiologic considerations for targeting activation of scapulothoracic muscles - part 1: serratus anterior.

BACKGROUND: The serratus anterior (SA) is capable of a wide range of actions across the scapulothoracic joint. Furthermore, the lack of control, strength, or activation of this important muscle is believed to be associated with several painful conditions involving the shoulder complex. Studies and clinical intuition have therefore identified several exercises that selectively target the activation of the SA. METHODS: This paper reviews the anatomy, innervation, testing, and complex actions of the SA. In addition, this paper describes the classic signs and symptoms of weakness or reduced activation of the SA. Several exercises are described and illustrated that purportedly target the activation of the SA, with the intention of optimizing muscular control and encouraging pain free shoulder motion. CONCLUSIONS: This review provides the theoretical background and literature-based evidence that can help explain the SA's complex pathokinesiology, as well as guide the clinician to further develop exercises that likely challenge the muscle. This paper is written along with a companion paper entitled: Kinesiologic considerations for targeting activation of scapulothoracic muscles: part 2: trapezius. Both papers prepare the reader to expand their pallet of exercises that target and challenge these two dominant muscles, with a goal of improving function of the shoulder for several painful conditions caused by their reduced or altered activation pattern.

Kinesiologic considerations for targeting activation of scapulothoracic muscles - part 2: trapezius.

BACKGROUND: The trapezius is an extensive muscle subdivided into upper, middle, and lower parts. This muscle is a dominant stabilizer of the scapula, normally operating synergistically with other scapular muscles, most notably the serratus anterior. Altered activation, poor control, or reduced strength of the different parts of the trapezius have been linked with abnormal scapular movements, often associated with pain. Several exercises have been designed and studied that specifically target the different parts of the trapezius, with the goal of developing exercises that optimize scapular position and scapulohumeral rhythm that reduce pain and increase function. METHODS: This paper describes the anatomy, kinesiology, and pathokinesiology of the trapezius as well as exercises that selectively target the activation of the different parts of this complex muscle. CONCLUSIONS: This review provides the anatomy and kinesiology of the trapezius muscle with the underlying intention of understanding how this muscle contributes to the normal mechanics of the scapula as well as the entire shoulder region. This paper can guide the clinician with planning exercises that specifically target the different parts of the trapezius. It is recommended that this paper be read as a companion to another paper: Kinesiologic considerations for targeting activation of scapulothoracic muscles - part 1: serratus anterior.

Effect of Posterior Capsule Tightness and Humeral Retroversion on 5 Glenohumeral Joint Range of Motion Measurements: A Cadaveric Study.

BACKGROUND: Altered glenohumeral joint range of motion can be caused by increased humeral retroversion (HR) and/or posterior capsule tightness (PCT). To make informed clinical decisions, it is vital to understand how HR and PCT alterations, individually and in combination, affect joint range of motion measurements. PURPOSE: To evaluate the effect of experimental tissue alterations on clinical range of motion measures. STUDY DESIGN: Controlled laboratory study. METHODS: Five clinical measurements were quantified in 8 fresh-frozen cadavers under 4 experimentally created conditions: baseline (no alterations), HR condition (20° increase in HR by transecting the bone), PCT condition (20% decrease in length via thermal energy), and PCT + HR combined. Clinical measurements included bicipital forearm angle, low flexion, glenohumeral internal and external rotation, and horizontal adduction. All measurements were taken by the same blinded tester. Separate 1-factor repeated measures analyses of variance were used to evaluate the effect of the alterations on each clinical measurement. RESULTS: There was a significant main effect of condition for bicipital forearm angle ( P = .02, F = 4.03), low flexion ( P = .02, F = 3.86), internal rotation ( P = .03, F = 3.65), and external rotation ( P < .001, F = 15.15) but not for horizontal adduction ( P = .29, F = 1.33). The HR condition resulted in a decreased bicipital forearm angle of 16.1° and 15.8° as compared with the PCT and PCT + HR conditions, respectively. When compared with baseline, the PCT + HR condition decreased the low flexion test by 13.5°, and the HR condition decreased internal rotation range of motion by 14.2°. All conditions increased external rotation when compared with baseline. CONCLUSION: Greater measurement changes were noted in both HR conditions, suggesting that bony alterations influence motion to a greater extent than posterior capsule alterations. CLINICAL RELEVANCE: Clinicians should be aware that humeral retroversion will influence the measurement of posterior shoulder tightness.

The Influence of Glenohumeral Joint Posterior Capsule Tightness and Impingement Symptoms on Shoulder Impairments and Kinematics.

BACKGROUND: Posterior capsule tightness (PCT) and shoulder impingement syndrome (SIS) symptoms are both associated with altered shoulder biomechanics and impairments. However, their combined effect on kinematics, pain, range of motion (ROM), strength, and function remain unknown. OBJECTIVE: The purpose of this study was to determine if the combination of PCT and SIS affects scapular and humeral kinematics, glenohumeral joint ROM, glenohumeral joint external rotation strength, pain, and function differently than does either factor (PCT or SIS) alone. DESIGN: The design was a cross-sectional group comparison. METHODS: Participants were placed into 1 of 4 groups based on the presence or absence of SIS and PCT: control group (n = 28), PCT group (n = 27), SIS group (n = 25), and SIS + PCT group (n = 25). Scapular kinematics and humeral translations were quantified with an electromagnetic motion capture system. Shoulder internal rotation and external rotation ROM, external rotation strength, and pain and Shoulder Pain and Disabilities Index scores were compared between groups with ANOVA. RESULTS: The SIS group had greater scapular internal rotation (mean difference = 5.13°; 95% confidence interval [CI] = 1.53°-8.9°) and less humeral anterior translation (1.71 mm; 95% CI = 0.53-2.9 mm) than the other groups. Groups without PCT had greater internal rotation ROM (16.05°; 95% CI = 5.09°-28.28°). The SIS + PCT group had lower pain thresholds at the levator scapulae muscle (108.02 kPa; 95% CI = 30.15-185.88 kPa) and the highest Shoulder Pain and Disabilities Index score (∼ 44.52; 95% CI = 33.41-55.63). LIMITATIONS: These results may be limited to individuals with impingement symptoms and cannot be generalized to other shoulder conditions. CONCLUSIONS: Decreased ROM and lower pain thresholds were found in individuals with both impingement symptoms and PCT. However, the combination of factors did not influence scapular and humeral kinematics.

Shoulder external rotation range of motion and pectoralis minor length in individuals with and without shoulder pain.

Background: There is evidence that pectoralis minor (PM) length influences scapula position and that scapula position relates to glenohumeral joint (GHJ) external rotation (ER) range of motion (ROM). Objectives: To explore the association between PM resting length and GHJ ER ROM in individuals with and without shoulder pain. The influence of GHJ ER ROM measurement position on this association was also evaluated. Design: Cross-Sectional. Methods: Fifty individuals (25 asymptomatic and 25 with shoulder pain) participated. PM resting length was measured using a tape measure with subjects standing, while GHJ ER ROM was quantified using a digital inclinometer with participants in both supine and seated positions. The same blinded investigator took all measurements. Results/Findings: A significant negative correlation between PM resting length and GHJ ER ROM in the seated position was noted in the asymptomatic group (r = -0.41; p = 0.04), but not in the symptomatic group (r = -0.33; p = 0.11). A nonsignificant negative correlation was also demonstrated in the supine position for both groups (r ranged from -0.35 to -0.17; p > 0.05). There was a significant group x position interaction (F = 4.06; p = 0.04) with more GHJ ER ROM (6.80°) for asymptomatic group in the seated position. Conclusions: PM length is not strongly correlated with GHJ ER ROM in individuals with or without shoulder pain. However, the position in which GHJ ER ROM is measured influenced the motion in asymptomatic individuals.

Abnormal isokinetic time-to-peak torque of the medial rotators of the shoulder in subjects with impingement syndrome.

The time-to-peak torque (TPT) and the peak torque ratio of the lateral to medial rotators (LR/MR) during isokinetic lateral and medial rotation of the shoulder were evaluated in patients with shoulder impingement and in healthy subjects. Fifteen patients with shoulder impingement on the dominant side and 9 healthy subjects were evaluated. TPT and LR/MR were measured bilaterally during isokinetic concentric lateral and medial rotation at 60 degrees/s and 180 degrees/s. The impingement group showed a bilateral decrease in the TPT during medial rotation for both 60 degrees/s and 180 degrees/s. No differences were found in the LR/MR between the groups. It is proposed that decreased (TPT) of the medial rotators can be used as a tool for early detection of shoulder impingement. Notably, the decreased time-to-peak torque of the medial rotators may occur before the alteration in the peak torque ratio.

The influence of posterior glenohumeral joint capsule tightness and humeral retroversion on clinical measurements.

OBJECTIVES: To assess the influence of posterior capsule tightness and humeral retroversion on shoulder motion measurements. DESIGN: Cross-Sectional study. SETTING: Controlled university laboratory. PARTICIPANTS: 75 asymptomatic individuals were assigned to one of 4 groups: control (n = 28); posterior capsule tightness only (n = 17); humeral retroversion only (n = 15); and combined posterior capsule tightness and retroversion (n = 15). MAIN OUTCOME MEASURES: Six clinical measurements were compared across groups: bicipital forearm angle, low flexion, glenohumeral internal and external rotation, horizontal adduction and extension with internal rotation. RESULTS: The group with both adaptations had decreased internal rotation compared to the control and retroversion only groups, as well as increased external rotation compared to the control and posterior capsule only groups. There were no between group differences for the horizontal adduction or extension with internal rotation measurements. The retroversion only and combined groups showed decreased bicipital forearm angle compared with the control and posterior tightness groups. The posterior capsule tightness and combined groups demonstrated decreased low flexion compared to the other groups. CONCLUSION: The combination of osseous and soft tissue adaptions alter shoulder motion measures more than a single adaption, making a comprehensive clinical assessment vital when managing individuals with shoulder pain.

Swimming Practice and Scapular Kinematics, Scapulothoracic Muscle Activity, and the Pressure-Pain Threshold in Young Swimmers.

CONTEXT: Whereas alterations in scapular kinematics, scapulothoracic muscle activity, and pain sensitivity have been described in adult swimmers, no researchers have examined these outcomes in young swimmers. OBJECTIVES: To compare scapular kinematics, scapulothoracic muscle activation, and the pressure-pain threshold (PPT) of the shoulder muscles among young nonpractitioners (those who were not involved in sports involving the upper limbs), amateur swimmers, and competitive swimmers. DESIGN: Cross-sectional study. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: A total of 90 individuals (age = 11.63 ± 0.61 years) in 3 groups: nonpractitioners, amateur swimmers, and competitive swimmers. INTERVENTION(S): Scapular kinematics and activity of the upper trapezius, lower trapezius, and serratus anterior (SA) were measured during upper extremity elevation in the scapular plane. The PPT was assessed in the upper trapezius, infraspinatus, supraspinatus, middle deltoid, and tibialis anterior. MAIN OUTCOME MEASURE(S): Scapular kinematics, scapulothoracic muscle activation, and PPT. We conducted a 2-way mixed-model analysis of variance and a 1-way analysis of variance for scapular rotation and PPT, respectively. A Kruskal-Wallis test was used to assess muscle activity. The α level was set at .05. RESULTS: Competitive swimmers presented more internal rotation at 90° ( P = .03) and 120° ( P = .047) and more anterior tilt at 90° ( P = .03) than nonpractitioners. Amateur swimmers demonstrated more anterior tilt at 90° ( P = .004) and 120° ( P = .005) than nonpractitioners. Competitive swimmers had greater SA activation in the intervals from 60° to 90° ( P = .02) and 90° to 120° ( P = .01) than amateur swimmers. They also displayed more SA activation in the interval from 90° to 120° than nonpractitioners ( P = .04). No differences were found in any of the muscles for the PPT ( P > .05). CONCLUSIONS: Young competitive swimmers presented alterations in scapular kinematics and scapulothoracic muscle activation during upper extremity elevation that may be due to sport practice. Mechanical pain sensitivity was not altered in young swimmers.