Effects of Repetitive Shoulder Activity on the Subacromial Space in Manual Wheelchair Users
Jun 17, Individuals with increased years of disability had greater AHD [1–3] The intrinsic factors include rotator cuff degeneration, aging, arthritis, acromial shape, and abnormalities including subacromial and acromioclavicular joint spurs. A secondary goal of this study was to examine the relationship between. Shoulder injuries are common in both young, athletic people and the aging population. are the result of impingement syndrome and age related changes within the rotator With age and the onset of arthritis, the acromion may develop bone spurs .. with a rotator cuff tear and continue to function without pain or disability. Nov 17, Unlabelled: Acromial spurs reportedly relate to the impingement spurs in of the patients (68%), and their incidence increased with age. The acromial spur was more common in the cuff tear group. Examining changes in acromial morphology in relation to spurs at the anterior edge of acromion.
Due to the limited size of the subacromial space, WR positioning is most likely to impinge the subacromial structures [ 7 ]. There is limited information on the impact of holding the WR position and isolated repetitive WR maneuvers on the subacromial space. Shoulder external rotation ER is a commonly prescribed training among MWUs to strengthen the shoulder external rotators to act against potentially injurious forces during wheelchair activities [ 8 ].
Shoulder external rotators, including infraspinatus, supraspinatus, posterior deltoid, and teres minor, are important for maintaining glenohumeral joint positioning [ 9 ]. Previous studies have found MWUs with paraplegia have comparative weakness of shoulder external rotators compared to shoulder internal rotators, resulting in shoulder muscle imbalances [ 10 ].
Shoulder muscle imbalances can lead to functional instability of the glenohumeral joint, resulting in the subacromial space narrowing and placing the individual at a higher risk of developing SIS [ 11 ]. Previous studies have implied the narrowing of the subacromial space after isolated repetitive ER in subjects with SIS or rotator cuff tear.
However, there is a knowledge gap regarding how the isolated repetitive ER contributes to subacromial space narrowing in the MWU population. We recently described a reliable method to quantify the subacromial space by using ultrasound while holding a WR position [ 12 ].
Ultrasound has the advantage of enabling the shoulder to be scanned in a functional posture. The primary purpose of this study was to investigate the subacromial space with the shoulder in an unloaded neutral position e. We hypothesized that the acromiohumeral distance AHDlinear measurement of the subacromial space, in the WR position, would be narrower than the baseline AHD. We also hypothesized that the AHD would be narrower after subjects completed each protocol compared to before the protocol.
A secondary goal of this study was to examine the relationship between shoulder pain, subject characteristics, and AHD. For a power of 0. The effect size was calculated based on ultrasound data collected from wheelchair users in previous reliability study [ 12 ].
Inclusion criteria included using a manual wheelchair as primary means of mobility, able to perform at least 10 WR in a row without assistance, and between 18 and 65 years of age.
The exclusion criteria included history of fractures or dislocations in the shoulder from which the subject had not fully recovered, upper limb dysesthetic pain as a result of a syrinx or complex regional pain syndrome, and history of cardiovascular or cardiopulmonary disease. Informed consent was obtained from all the subjects before participation in this study. The WUSPI is a reliable and validated item self-report instrument that measures shoulder pain intensity in wheelchair users in the last seven days during various functional activities of daily living including transfers, wheelchair mobility, dressing, overhead lifting, and sleeping [ 14 ].
The OMNI pain scale is a numerical rating scale ranging from 0 to 10 [ 16 — 18 ]. The OMNI pain scale has been previously validated for walking, running, and cycle ergometer exercise and for use by male and female adults during upper and lower body resistance exercise.
The OMNI scale was administered prior to the beginning of testing, to establish a baseline measure of pain, and after each activity, to determine the intensity of activity-induced pain experienced during the testing. Procedure Shoulder circumference and upper arm length were obtained from all subjects at the beginning of testing. The shoulder circumference and upper arm length were measured while the subjects were in the seated anatomical position.
The shoulder circumference was measured from the superior portion of the acromion to the axilla. The upper arm length was measured from the most lateral and superior portion of the acromion to the tip of the olecranon. A single investigator conducted all of the measurements using a standard tape measure. Using this method to record similar anthropometrical measures has been found to be reliable [ 19 ].
Armrests were fitted to each subject to allow pushing straight up with full elbow extension to off load the buttock tissue. The seat height was fixed during the entire testing. The WR entailed lifting and holding the buttocks off the seat with an elbow locked position [ 45 ]. The WR task was repeated at a rate of 30 repetitions per minute to the auditory cue of a metronome. Subjects were instructed to stop when they were no longer able to continue or until they completed two minutes of activity.
The total number of WR raises 60 is similar to the number that would be performed each day in case of following the recommended frequency of pressure relief one time every 15 to 30 minutes [ 20 ].
The ER task followed a similar protocol to a previous study involving neurologically intact individuals without shoulder disorders and was designed to overuse the shoulder external rotators [ 21 ].
The trunk was secured to minimize compensatory movements using straps from the Biodex that crossed the chest and lap. The strap has been used in previous studies to support targeted joint movements among spinal cord injured and able-bodied subjects [ 2324 ].
The dynamometer was adjusted to match the level of their tested and nontested shoulders before the ER activity. To minimize the involvement of the shoulder internal rotators, the minimum resistance setting of 0. ER protocols were administered at the same pace and ended in the same manner as the WR task. The subjects rested in between the two protocols for a period of approximately 15 minutes.
AHD Ultrasound Examination The subacromial space was quantified by measuring the AHD using ultrasound techniques as described in a previous reliability study [ 12 ]. The intrarater reliability of the AHD measurement with the shoulder in a neutral and WR position resulted in a standard error of measurement of 0.
A single examiner conducted all scans for each subject using a Philips HD11 1. A water-based gel was applied on the skin to enhance conduction between the ultrasound probe and skin surface. The nondominant side was chosen for all the AHD measures in order to minimize the effects caused by performing other types of activities of daily living on the dominant shoulder.
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The muscular demand of the nondominant shoulders among manual wheelchair users was also examined in previous studies [ 27 ]. The nondominant shoulder was scanned from the anterior aspect of glenoid to the flat segment of posterior acromion to capture the bright reflection of the bony contour of the acromion and humeral head Figure 1. For diagnostic accuracy research or prognosis, etiology or side effects: A1-level study or at least 2 independently conducted A-2 level studies.
Results Clinical Question 1: What is known about the prognosis of SAPS? Scientific evidence level 1: There is an association between being middle-aged 45—54 years and worse outcome Kuijpers et al.
There are indications that a worse outcome is associated with a worse score at the start, longer duration of symptoms, and type II or III acromion morphology Taheriazam et al. There is evidence that psychosocial factors play a role in chronic complaints.
What measures are effective in preventing SAPS? Psychosocial factors associated with prolonged shoulder complaints are high psychological demands, low control, low social support, low job satisfaction, and high pressure to perform van Rijn et al. Considerations There were fewer modifiable factors found in studies on psychosocial risks than in studies on physical factors. In one study Kennedy et al.
However, there have been no studies on the effects of these interventions. Which physical diagnostic tests are most accurate, sensitive and specific for subacromial pain syndrome of the shoulder?
The inter-rater reliability of the most common tests varies greatly. Inter-rater reliability of active abduction and abduction trajectory pain is moderate May et al.
The combination of a number of tests increases the post-test probability of the diagnosis of SAPS. Murrell and WaltonPark et al. Considerations As one physical sign cannot sufficiently differentiate between the various shoulder disorders, or give a clear distinction regarding the status of the rotator cuff, a combination of multiple tests increases post-test probability of a diagnosis of SAPS.
Recommendations To determine SAPS, a combination of the Hawkins-Kennedy test, the painful arc test, and the infraspinatus muscle strength test should be used; and for a rotator cuff tear, the drop-arm test and the infraspinatus and supraspinatus muscle strength tests should be used.
What is the added value of imaging tests for diagnosis of SAPS? The sensitivity and specificity of ultrasound and conventional MRI are not significantly different in the detection of partial- or full-thickness rotator cuff tears Dinnes et al. MR arthrography is an accurate method to rule out partial rotator cuff injuries de Jesus et al.
It is likely that ultrasound is an accurate method for the detection or exclusion of rotator cuff tendinopathy, subacromial bursitis, biceps tendon rupture, and tendinosis calcarea Ottenheijm et al. The interobserver variability of ultrasound with respect to detection of rotator cuff injuries is low, as the results are very similar Rutten et al. There is evidence that ultrasound is not sufficiently reliable to differentiate between an intact rotator cuff and partial lesions Sipola et al.
Considerations Ultrasound of the shoulder is a sensitive and specific method. The diagnostic accuracy is good and comparable to that of conventional MRI for identification and quantification of complete full-thickness rotator cuff injuries. There are conflicting results about the value of ultrasonography in partial rotator cuff tears and tendinopathies.
For optimal sonographic analysis of the shoulder, standardized examination and expertise as well as high-quality equipment 7. When repair of a rotator cuff tear is intended, MRI provides useful information on size, retraction, and matching atrophy and fatty infiltration. For the detection of partial articular side cuff injuries PASTA lesionsMR arthrography may be considered because of its high sensitivity and specificity.
Although a correlation has been described between the shape of the acromion type III, angled and the presence of rotator cuff injuries Toivonen et al. Recommendations Ultrasound is advised as the most valuable and cost-effective diagnostic imaging if a first period of non-operative treatment fails. MRI of the shoulder is indicated when reliable ultrasound is not at hand or inconclusive, and should be used in patients who are eligible for surgical repair of a cuff tear to assess the degree of retraction and atrophied fatty infiltration.
An MRI study with intra-articular contrast can be considered if any intra-articular abnormality or a partial rotator cuff injury have to be ruled out. Which instruments are most suitable for measuring the outcome of treatment of SAPS? Scientific evidence level 2: Measurements of ROM using instruments in goniometry and inclinometry are more reliable than those based on visual assessment van de Pol et al. The internal consistency and test-retest reliability of the Dutch Simple Shoulder Test seem high and the construct validity moderate to good van Kampen et al.
There is insufficient inter-rater reliability of visual estimation of ROM Terwee et al. There are indications that the inter-rater reliability of ROM measured using a digital inclinometer for individual patients is poor, with differences in ROM of less than 20—25 degrees being indistinguishable from measurement error de Winter et al. The English Oxford Shoulder Score has a high test-retest reliability, high internal consistency, and a weak-to-moderate criterion validity Berendes et al.
Subacromial impingement syndrome
The Dutch Shoulder Rating Questionnaire has high internal consistency, high test-retest reliability, moderate-to-good criterion validity, and is an appropriate instrument to demonstrate clinical differences Vermeulen et al. This suggests that direct encroachment of the subacromial space by the coracoacromial arch soft tissue or bony changes is not the only mechanism of impingement.
Supporting this theory of a requisite overuse exposure, symptomatic RC disease is more often present in dominant than nondominant shoulders. These include shortening of the posterior-inferior glenohumeral joint capsule and decreased RC muscle performance. When posterior capsular tightness was surgically induced in cadavers, there was an in increase in superior and anterior humeral head translations during passive glenohumeral flexion. Excessive superior and anterior humeral head translations can decrease the size of the subacromial space, leading to increased mechanical compression of the subacromial structures.
Furthermore, stretching to address impairments of posterior shoulder tightness has been identified as an important component to rehabilitation for patients with RC tendinopathy. Excessive superior translation of the humeral head resulting from rotator cuff weakness can lead to a decrease in the subacromial space during elevation, and thus increased mechanical compression of the subacromial contents.
The pain is typically localized to the anterolateral acromion and frequently radiates to the lateral mid-humerus.
Patients usually complain of pain at night, exacerbated by lying on the involved shoulder, or sleeping with the arm overhead. Normal daily activities such as combing one's hair or reaching up into a cupboard become painful.
Weakness and stiffness may also be encountered, but they are usually secondary to pain. In their meta-analysis, Hegedus et al. Imaging Standard radiographs including internal and external rotation anteroposterior, scapular Y, axillary, and Supraspinatus outlet views are important for the thorough evaluation of shoulder pain.
These plain radiographs may show characteristic changes of rotator cuff disease, including subacromial osteophytes,subacromial sclerosis, cystic changes of the greater tuberosity, and narrowing of the acromiohumeral distance, they are not definitive. Ossification of the coracoacromial ligament CAL or presence of a subacromial spur can be best identified in the sagittal oblique plane; however, differentiation of a pathologic spur and the normal CAL can be difficult.
Typically, MRI is performed with the arm adducted; however, this position does not recreate the position of impingement. In the last decade, several systematic reviews on treatment for impingement syndrome were published.
Hence, the conclusion on effectiveness of various treatments was primarily based on the combination of these outcome measures. There is strong evidence that extracorporeal shock-wave therapy is no more effective than placebo, 3233 moderate evidence that ultrasound therapy is no more effective than placebo, 34 and limited evidence that laser is no more effective than placebo with regard to functional limitations.
On the short term, arthroscopic acromioplasty is more effective than open acromioplasty with regard to functional limitations and return to work. However, moderate evidence exists that on the long term open and arthroscopic acromioplasty are equally effective with regard to functional limitations.
Evidence suggests that extrinsic, intrinsic, and combinations of biomechanical mechanisms play a role.
There are no significant differences in outcome between conservatively and surgically treated patients with subacromial impingement syndrome. For most patients with SAIS, nonsurgical treatment is successful.
Surgical intervention is successful in patients who fail nonsurgical treatment. Surgeon experience and intraoperative assessment may guide the method of surgical treatment. Studies have shown that many surgical interventions, including debridement and open and arthroscopic acromioplasty, have been successful.
However, there remains a need for high-quality clinical research on the diagnosis and treatment of SAIS. Shoulder disorders in general practice: J Bone Joint Surg Am. Clin Orthop Relat Res. Anatomical and biomechanical mechanisms of subacromial impingement syndrome.
Clin Biomech Bristol, Avon ; Glenohumeral elevation studied in three dimensions. J Bone Joint Surg Br. Translations of the humerus in persons with shoulder impingement symptoms. J Orthop Sports Phys Ther. Translation of the glenohumeral joint with simulated active elevation. Excursion of the rotator cuff under the acromion.
Patterns of subacromial contact. Am J Sports Med. Three-dimensional recording and description of motions of the shoulder mechanism.