Quantified measurement of subacromial impingement

Clinical effectiveness of high induction electromagnetic stimulation in patients with subacromial impingement syndrome: A single-blinded randomized controlled trial

BackgroundHigh Induction Electromagnetic Stimulation (HIES) is a new treatment modality. The clinical effectiveness of HIES applied in addition to conservative treatment in patients with Subacromial Impingement Syndrome (SIS) is unclear.ObjectiveTo examine the effects of HIES, applied in addition to conservative treatment on symptoms, functions, and activities of daily life in patients with SIS.MethodsA total of 36 participants diagnosed with SIS were included in the single- blinded randomized controlled study. The Visual Analog Scale (VAS) for pain intensity, the Disabilities of the Arm, Shoulder, and Hand Questionnaire (DASH) for upper extremity physical function, and the Constant-Murley Score (CMS) for the level of disability were used. The range of motion (ROM) measurements of the shoulder joint were performed using a goniometer. In the four-week rehabilitation program, one group (n = 19) received conservative treatment for 45 min, five days a week. The other group (n = 17) received HIES in addition to conservative treatment, applied in 10-min sessions with a one-day interval between sessions, for a total of 10 sessions.ResultsPost-treatment DASH score was found to be lower in the HIES group than in the conservative treatment group (p < 0.01). When the delta values obtained by subtracting the pre-treatment measurements from the post-treatment measurements were examined, the ΔVAS (p = 0.037) and ΔDASH (p < 0.01) values were significantly different between the two groups.ConclusionsHIES applied in addition to conservative treatment in patients diagnosed with SIS is more effective than conservative treatment alone in improving clinical outcomes and reducing pain.

Investigating the reliability and validity of subacromial space measurements using ultrasound and MRI

BACKGROUND

While ultrasound (US) measures of the subacromial space (SAS) have demonstrated excellent reliability, measurements are typically captured by experts with extensive ultrasound experience. Further, the agreement between US measured SAS width and other imaging modalities has not been explored. This research evaluated the agreement between SAS measures captured by novice and expert raters and between US and magnetic resonance imaging (MRI). This study also evaluated the effect of US transducer tilt on measured SAS.

METHODS

Nine men and nine women participated in this study. US images were captured by a novice and expert with the participant in both seated and supine positions. An inclinometer was fixed to the US probe to measure transducer tilt. SAS width was measured in real time from freeze framed images. MRI images were captured, and the humerus and acromion manually segmented. The SAS width was measured using a custom algorithm.

RESULTS

Intraclass correlation coefficients (ICCs) between novice and expert raters were 0.74 and 0.63 for seated and supine positions, respectively. Intra-rater agreement was high for both novice (ICC = 0.83-0.84) and expert (ICC ≥ 0.94) raters. Agreement between US and MRI was poor (ICC = 0.21-0.49) but linearly related.

CONCLUSIONS

Moderate agreement between novice and expert raters was demonstrated, while the agreement between US and MRI was poor. High intra-rater reliability within each rater suggests that US measures of the SAS may be completed by a novice with introductory training.

Comparison of acromiohumeral distance and glenohumeral internal rotation angle between the empty can test and modified empty can test: "thumb pointing down" versus "elbow pointing laterally"

BACKGROUND

During the empty can test, the direction of the thumb (downward) has been widely used as an instruction for producing glenohumeral internal rotation. However, the combination of forearm pronation and thumb motion as a compensatory movement could contribute to the lack of glenohumeral internal rotation during the empty can test. This study aimed to compare the glenohumeral internal rotation angle between the conventional empty can (with thumb direction) and modified empty can tests (with elbow direction), as well as the acromiohumeral distance between the full can, conventional empty can, and modified empty can tests.

METHODS

In this laboratory study, we measured the glenohumeral internal rotation angle using a motion sensor and the acromiohumeral distance using ultrasonography during the following tests: full can test (thumb pointing up), conventional empty can test (thumb pointing down), and modified empty can test (elbow pointing laterally) in 20 healthy subjects.

RESULTS

Compared with the conventional empty can test, the glenohumeral internal rotation angle was significantly greater during the modified empty can test (p < 0.05). Furthermore, the acromiohumeral distance measured in the modified empty can test was significantly less than that in the full can test (p < 0.001) and conventional empty can test (p < 0.001). However, there was no difference in the acromiohumeral distance between the full can test and the conventional empty can test (p > 0.017).

CONCLUSIONS

During the empty can test, the instructions should be given to patients based on the elbow direction (elbow pointing laterally). The modified empty can test can produce full glenohumeral internal rotation, compared with instructions based on the thumb direction (thumb pointing down). Consequently, the modified empty can test can produce a more decreased subacromial space.

Movement System Dysfunction Applied to Youth and Young Adult Throwing Athletes

Shoulder and elbow injuries in overhead athletes, especially baseball pitchers, have become more common and result in limited participation. Upper extremity injuries in baseball can occur secondary to high velocity repetitive loading at extreme ranges of motion causing microtrauma to the musculoskeletal structures. With the vast number of youth and young adult baseball players in the United States and the increasing number of throwing related injuries, it is crucial that clinicians can perform a movement system evaluation of the throwing motion. An adequate evaluation of the movement system as it relates to the throwing motion can provide insight into abnormal throwing mechanics and provide rationale for selecting appropriate interventions to address identified impairments that may lead to injury. The purpose of this clinical commentary is to present a recommended movement system evaluation that can be utilized during both pre-season and in-season to assess for modifiable injury risk factors in youth and young adult baseball players.

LEVEL OF EVIDENCE

5.

Evolution of nonoperative treatment of atraumatic sternoclavicular dislocation

BACKGROUND

Atraumatic sternoclavicular dislocation (ASCD) is an uncommon pathology that is mainly diagnosed in young adults. The aim of this study is to better describe the clinical picture of ASCD and to describe the results of a "wait-and-see" policy in these patients.

METHODS

All patients with ASCD who visited our department between 2011 and 2016 were retrospectively analyzed. A standardized clinical examination was used to evaluate the clinical picture. All patients were treated nonoperatively, and at latest follow-up, several parameters and standardized questionnaires (Nottingham Clavicle Score, Oxford Shoulder Score, Constant-Murley Score) were used to evaluate the outcome.

RESULTS

In total, 23 patients (12 male, 11 female) were evaluated. The average age at diagnosis was 18.6 years. There was a significant difference (P < .001) in angle of dislocation during forward flexion (mean = 141°) compared with abduction (mean = 101°). At latest follow-up (average 46 months, range 14-113 months; standard deviation [SD] = 27), subluxations still occurred but were less frequent and less prominent relative to presentation at initial diagnosis in 19 of 23 patients. The chance of subjective improvement increased by 27% for each year of follow-up. High outcome scores of Nottingham Clavicle Score (mean score = 80, SD = 11), Oxford Shoulder Score (mean score = 44, SD = 4), and Constant-Murley Score (mean score = 83, SD = 11) were reported.

CONCLUSION

In patients with ASCD, the clavicle subluxates earlier in abduction than in forward flexion. After a midterm follow-up, a "wait-and-see" policy does not resolve the subluxations. However, most patients displayed reduced frequency and severity of subluxations over their recovery period and showed excellent scores on shoulder questionnaires.

Shoulder Injuries in the Overhead Throwing Athlete

The overhead pitching motion is a coordinated sequence of movements that subjects the shoulder to extreme forces. The ultimate goal of this complex, dynamic activity is to generate high ball velocity and accuracy. In doing so, repetitive throwing can cause adaptive and pathologic changes in the thrower's shoulder. This article reviews the relevant shoulder anatomy, the kinetic chain, and throwing mechanics, as well as common shoulder injuries and surgical options for the treating orthopedic surgeon.

Ultrasound evaluation of the subacromial space in healthy subjects performing three different positions of shoulder abduction in both loaded and unloaded conditions

BACKGROUND

Subacromial space (SS) narrowing may result in unsafe contact of rotator cuff tendons and bursa with the acromion, possibly promoting rotator cuff pathologies and pain. We measured SS in asymptomatic subjects after three movements employed for shoulder muscles' training.

PARTICIPANTS AND MAIN OUTCOME MEASURES

Twenty-five males (age 24±5years; stature 175±8 cm; body mass 74±12 kg) underwent SS ultrasound evaluation while executing with (WL) and without (NL) 4-kg load: 90° shoulder abduction (SA) without humerus rotation (90°_neutral); 90° SA maximal humeral external rotation (90°_er); maximum SA (above 90°) during upright row (UR). For inter-operator reliability analysis, a subset of 12 subjects was assessed by two operators.

RESULTS

Intra/inter-operator reliability coefficients were high (ICC>0.87; standard error of measurement range: 0.23-0.51 mm; minimum detectable change range: 0.61-1.79 mm). ANOVA revealed significant differences between loads (p = 0.003, η² = 0.37) and angles (p < 0.001, η² = 0.72), and interaction (p = 0.004, η² = 0.45). Normalized SS values WL were higher at 90°_er vs. 90°_neutral and UR (p < 0.001 for both). Differences in NL were found between 90°_neutral and both 90°_er (p = 0.002) and UR (p = 0.009).

CONCLUSIONS

When holding a 4-kg load, SS is larger at 90°_er than at 90°_neutral and UR shoulder abduction positions. In unloaded condition, SS at 90°_neutral is reduced compared to 90°_er and UR.

The effects of plane and arc of elevation on electromyography of shoulder musculature in patients with rotator cuff tears

BACKGROUND

Arm elevations in different planes are commonly assessed in clinics and are included in rehabilitation protocols for patients with rotator cuff pathology. The aim of this study was to quantify the effect of plane and angle of elevation on shoulder muscles activity in patients with symptomatic rotator cuff tear to be used for rehabilitation purposes.

METHODS

Eight symptomatic patients with rotator cuff tears were assessed by using EMG (11 surface and 2 fine wire electrodes) synchronized with a motion analysis. The subjects completed five elevations in full can position (arm externally rotated and thumb up) in frontal, scapular and sagittal planes. Muscle activity in three elevation arcs of 20° (from 0° to 60°) was presented as the percentage of mean activity. Data were analyzed by mixed linear models (α=0.003), and Tuckey Post-hoc comparisons for significant effects (α=0.05).

FINDINGS

The effect of plane was significant for supraspinatus, middle trapezius, anterior, middle, and posterior deltoid, triceps, and pectoralis major (P<0.001). Supraspinatus was more active during abduction than scaption and flexion (P<0.05), and its activity did not increase significantly after 40° of elevation (P>0.05). Infraspinatus had similar activity pattern in the three planes of elevation (P>0.003) with increasing trend in accordance with the elevation angle.

INTERPRETATION

In any rehabilitation protocol, if less activity of supraspinatus is desired, active arm elevation should be directed toward flexion and scaption and postponed abduction to prevent high level of activity in this muscle.

Shoulder Coordination During Full-Can and Empty-Can Rehabilitation Exercises

CONTEXT

Supraspinatus tear is a common rotator cuff injury. During rehabilitation, debate persists regarding the most appropriate exercises. Whereas shoulder coordination is part of normal arm function, it has been infrequently considered in the context of exercise selection.

OBJECTIVE

To assess shoulder-motion coordination during 2 common supraspinatus rehabilitation exercises and to characterize load and motion-direction influences on shoulder coordination.

DESIGN

Descriptive laboratory study.

SETTING

Motion-analysis laboratory. Patient or Other Participants :  Fifteen asymptomatic right-hand-dominant men (age = 26 ± 4 years, height = 1.77 ± 0.06 m, mass = 74.3 ± 7.7 kg).

INTERVENTION(S)

Full-can and empty-can exercises with and without a 2.27-kg load.

MAIN OUTCOME MEASURE(S)

We recorded motion with an optoelectronic system. Scapulohumeral rhythm and complete shoulder joint kinematics were calculated to quantify shoulder coordination. The effects of exercise type, load, motion direction, and humerothoracic-elevation angle on the scapulohumeral rhythm and shoulder-joint angles were assessed.

RESULTS

We observed multivariate interactions between exercise type and humerothoracic elevation and between load and humerothoracic elevation. Scapulohumeral rhythm increased by a mean ratio of 0.44 ± 0.22 during the full-can exercise, whereas the addition of load increased mean glenohumeral elevation by 4° ± 1°.

CONCLUSIONS

The full-can exercise increased the glenohumeral contribution, as hypothesized, and showed normal shoulder coordination. During the empty-can exercise, the increased scapulothoracic contribution was associated with a compensatory pattern that limits the glenohumeral contribution. Using loads during shoulder rehabilitation seems justified because the scapulohumeral rhythm is similar to that of unloaded arm elevation. Finally, motion direction showed a limited effect during the exercises in healthy individuals.

Differences in scapular orientation, subacromial space and shoulder pain between the full can and empty can tests

BACKGROUND

The empty and full can arm positions are used as diagnostic tests and in therapeutic exercise programs for patients with subacromial impingement syndrome. The adverse effects of these arm positions on the rotator cuff have not been fully described. The purpose of this investigation was to compare the acromio-humeral distance, three-dimensional scapular position, and shoulder pain during maximum isometric contractions in the empty and full can arm positions.

METHODS

Subjects with subacromial impingement syndrome (n=28) and a matched control group without shoulder pain (n=28) participated. Acromio-humeral distance, scapular/clavicular positions and shoulder pain were measured during maximal isometric contractions in each position.

FINDINGS

No difference was found in acromio-humeral distance (P=0.314) between the arm positions or between the groups (P=0.598). The empty can position resulted in greater scapular upward rotation (P<0.001, difference=4.9°), clavicular elevation (P<0.001, difference=2.7°), clavicular protraction (P=0.001, difference=2.5°) and less posterior tilt (P<0.001, difference=3.8°) than the full can position. No differences in the scapular positions were found between the groups. Positive correlations were seen between the scapular positions in the control and not in the subacromial impingement group.

INTERPRETATION

Our results did not show a difference in acromio-humeral distance between the arm positions or groups, indicating that the kinematic differences between the positions are not associated with altered acromio-humeral distance. The increased pain in the EC position might be due to the lack of an association amongst the scapular positions rather than the deficiency of a single scapular motion.

Dynamic visualization of the coracoacromial ligament by ultrasound

Subacromial impingement syndrome (SIS) is prevalent in athletes who make throwing motions over their heads, as well as in the normal population, but it is difficult to diagnose precisely using physical examination and traditional imaging modalities. Furthermore, the diagnostic testing protocols have not been strictly standardized. We used ultrasound to dynamically visualize coracoacromial ligament (CAL) morphology during shoulder impingement tests: the CAL is the key impinging structure in SIS. Fifty normal shoulders were examined. With the transducer placed on the CAL, the shoulders were examined with seven different testing protocols described in the literature. The degree of CAL bulge from the resting position was measured, and the degree of bulge in different testing protocols was compared. We found that the Hawkins-Kennedy impingement test caused more CAL bulge than the Neer's impingement test, and the most prominent morphological change in the CAL occurred with an internally rotated and horizontally abducted shoulder. We conclude that high-resolution ultrasound is an excellent tool for dynamically inspecting the impinging structures, is applicable in clinical settings, and allows more accurate diagnosis of SIS.

Current concepts in the scientific and clinical rationale behind exercises for glenohumeral and scapulothoracic musculature

SYNOPSIS

The biomechanical analysis of rehabilitation exercises has led to more scientifically based rehabilitation programs. Several investigators have sought to quantify the biomechanics and electromyographic data of common rehabilitation exercises in an attempt to fully understand their clinical indications and usefulness. Furthermore, the effect of pathology on normal shoulder biomechanics has been documented. It is important to consider the anatomical, biomechanical, and clinical implications when designing exercise programs. The purpose of this paper is to provide the clinician with a thorough overview of the availableliterature relevant to develop safe, effective, and appropriate exercise programs for injury rehabilitation and prevention of the glenohumeral and scapulothoracic joints.

LEVEL OF EVIDENCE

Level 5.

Intra- and interexaminer reliability of four manual shoulder maneuvers used to identify subacromial pain

Shoulder pain is a diagnostic challenge and the physical clinical examination of the shoulder is crucial. It is important that the diagnostic tests used are valid as well as reliable. The objective of the study was to assess intra- and interexaminer reliability for four manual shoulder maneuvers; the Neer impingement sign, the Hawkins-Kennedy impingement test, the Patte maneuver, the Jobe supraspinatus test. These maneuvers are frequently used in clinical practice to examine patients with shoulder complaints in which subacromial pain is highly suspected. Thirty-three participants with shoulder pain were included consecutively. Within a week from inclusion, the four maneuvers were performed by a physiotherapist. The procedure was standardized in order to increase reproducibility. After a week, the maneuvers were performed again by the same physical therapist (test-retest) and by another physical therapist (test for interexaminer reliability). All four maneuvers have an almost perfect agreement (Kappa coefficients 0.91-1.00), if performed with suggested standardizations. Neer impingement sign, Hawkins-Kennedy impingement test, Patte maneuver as well as Jobe supraspinatus test, are highly reproducible and therefore reliable to use in clinical practice to identify patients with subacromial pain with an impingement phenomenon, but the maneuvers are limited as structural discriminators.

In vivo measurement of subacromial space width during shoulder elevation: technique and preliminary results in patients following unilateral rotator cuff repair

BACKGROUND

The shoulder's subacromial space is of significant clinical interest due to its association with rotator cuff disease. Previous studies have estimated the subacromial space width to be 2-17 mm, but no study has measured in vivo subacromial space width during shoulder motion. The purpose of this study was to measure the in vivo subacromial space width during shoulder elevation in patients following rotator cuff repair.

METHODS

Biplane X-ray images were collected during shoulder elevation of 11 patients who had undergone rotator cuff repair. Glenohumeral joint motion was measured from the biplane X-ray images for each subject's repaired and asymptomatic, contralateral shoulders. The joint motion data were combined with subject-specific CT models to measure the subacromial space width during shoulder motion.

FINDINGS

Subacromial space width decreased with shoulder elevation, ranging from 2.3 to 7.4 mm in the repaired shoulder and 1.2-7.1 mm in the contralateral shoulder. Subacromial space width in the repaired shoulder was only 0.5 mm less than the contralateral shoulder when averaged over 10-60 degrees of glenohumeral elevation.

INTERPRETATION

The results indicate that the humerus in the repaired shoulder is positioned more cranially on the glenoid than in the contralateral shoulder. It is unclear if these subtle differences in subacromial space width are due to the surgical procedure or post-operative stiffness, or if subacromial impingement contributed to the development of the rotator cuff tear. Future research will ascertain if these results represent a transient response to the surgery or a more fundamental difference in rotator cuff function between repaired and contralateral shoulders.

Scapular kinematics during supraspinatus rehabilitation exercise: a comparison of full-can versus empty-can techniques

BACKGROUND

Supraspinatus strengthening is an important component of shoulder rehabilitation. Previous work has determined that the full-can and empty-can exercises elicit the greatest amount of supraspinatus activity. However, scapular kinematics has not been considered when prescribing supraspinatus exercises.

HYPOTHESIS

Scapular downward rotation, internal rotation, and anterior tipping during the empty-can exercise are increased when compared with the full-can exercise.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Twenty participants performed full-can and empty-can exercises while an electromagnetic tracking system was used to collect three-dimensional scapular kinematic data. Scapular angles at 30 degrees, 60 degrees, and 90 degrees of the ascending and descending phases of humeral elevation were compared using 2-way repeated measures analysis of variance.

RESULTS

There was more scapular anterior tipping and internal rotation during the empty-can exercise at all sampled humeral elevation angles except at 30 degrees of the descending phase for anterior/posterior tipping (P < .05).

CONCLUSION

Scapular anterior tipping and internal rotation are increased during the empty-can exercise, whereas scapular upward rotation was not different between exercises.

CLINICAL RELEVANCE

Increased scapular internal rotation and anterior tipping decrease the volume of the supraspinatus outlet during the empty-can exercise. When maintenance of the subacromial space is important, use of the full-can exercise seems most appropriate for selective strengthening of the supraspinatus muscle.