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.

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.

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.

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.

Reliability of measuring pectoralis minor muscle resting length in subjects with and without signs of shoulder impingement

Background: Pectoralis minor adaptive shortening may change scapula resting position and scapular kinematics during arm elevation. A reliable and clinically feasible method for measuring pectoralis minor length will be useful for clinical decision making when evaluating and treating individuals with shoulder pain and dysfunction. Objectives: To evaluate intrarater, interrater, and between-day reliability of a pectoralis minor (PM) muscle length measurement in subjects with and without signs of shoulder impingement. Method: A convenience sample of 100 individuals (50 asymptomatic and 50 symptomatic) participated in this study. Intra- and interrater reliability of the measurement was estimated in 50 individuals (25 asymptomatic and 25 symptomatic), and between-day reliability of the measurement repeated over an interval of 7 days was estimated in an independent sample of 50 additional participants. Pectoralis minor length was measured using a flexible tape measure with subjects standing. Results: Intraclass correlation coefficients (ICC3,k) for intrarater and interrater reliability ranged from 0.86-0.97 and 0.95 for between-day reliability in both groups. Standard error of measurements (SEM) ranged from 0.30-0.42 cm, 0.70-0.84 cm, and 0.40-0.41 cm for intrarater, interrater, and between-day reliability, respectively, across the sample. The minimal detectable change (MDC) for between-day measurements ranged from 1.13-1.14 cm for both groups. Conclusions: In asymptomatic individuals and in those with signs of shoulder impingement, a single rater or pair of raters can measure pectoralis minor muscle length using a tape measure with very good reliability. This measurement can also be reliably used by the same rater over a seven day interval.

Reliability of measuring pectoralis minor muscle resting length in subjects with and without signs of shoulder impingement.

BACKGROUND: Pectoralis minor adaptive shortening may change scapula resting position and scapular kinematics during arm elevation. A reliable and clinically feasible method for measuring pectoralis minor length will be useful for clinical decision making when evaluating and treating individuals with shoulder pain and dysfunction. OBJECTIVES: To evaluate intrarater, interrater, and between-day reliability of a pectoralis minor (PM) muscle length measurement in subjects with and without signs of shoulder impingement. METHOD: A convenience sample of 100 individuals (50 asymptomatic and 50 symptomatic) participated in this study. Intra- and interrater reliability of the measurement was estimated in 50 individuals (25 asymptomatic and 25 symptomatic), and between-day reliability of the measurement repeated over an interval of 7 days was estimated in an independent sample of 50 additional participants. Pectoralis minor length was measured using a flexible tape measure with subjects standing. RESULTS: Intraclass correlation coefficients (ICC3,k) for intrarater and interrater reliability ranged from 0.86-0.97 and 0.95 for between-day reliability in both groups. Standard error of measurements (SEM) ranged from 0.30-0.42 cm, 0.70-0.84 cm, and 0.40-0.41 cm for intrarater, interrater, and between-day reliability, respectively, across the sample. The minimal detectable change (MDC) for between-day measurements ranged from 1.13-1.14 cm for both groups. CONCLUSIONS: In asymptomatic individuals and in those with signs of shoulder impingement, a single rater or pair of raters can measure pectoralis minor muscle length using a tape measure with very good reliability. This measurement can also be reliably used by the same rater over a seven day interval.

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.