Electromyographic activities of the subscapularis, supraspinatus and infraspinatus muscles during passive shoulder and active elbow exercises

Regaining motion among patients with shoulder pathology - are all exercises equal?

Background

Little information exists to guide the choice of exercise for regaining shoulder range of motion (ROM). The purpose of this study was to compare the maximal ROM reached, pain and difficulty associated with 4 commonly prescribed exercises.

Methods

Forty (9 females) patients with various shoulder disorders and a limited flexion ROM performed 4 exercises for regaining shoulder flexion ROM in a randomized order. Exercises included the self-assisted flexion, forward bow, table slide and rope-and-pulley. Participants were videotaped while performing all exercises and the maximal flexion angle reached during each exercise was recorded using Kinovea motion analysis freeware (Kinovea 0.8.15). Pain intensity and the perceived level of difficulty associated with each exercise were also recorded.

Results

The forward bow and table slide generated significantly greater ROM compared with the self-assisted flexion and rope-and-pulley (P ≤ 0.005). The self-assisted flexion was associated with a greater pain intensity compared with the table slide and rope-and-pulley (P = 0.002) and a greater perceived level of difficulty compared with the table slide (P = 0.006).

Conclusions

Due to the greater ROM allowed, and similar or even lower level of pain or difficulty, clinicians may wish to initially recommend the forward bow and table slide for regaining shoulder flexion ROM.

Comparison of Knotless and Knotted Single-Anchor Repair for Ruptures of the Upper Subscapularis Tendon: Outcomes at 2-Year Follow-up

Background:

Both knotted and knotless single-anchor repair techniques are used to repair transmural ruptures of the upper subscapularis (SSC) tendon. However, it is still unclear which technique provides better clinical and radiological results.

Purpose/Hypothesis:

To compare the clinical and magnetic resonance imaging (MRI) outcomes of knotless and knotted single-anchor repair techniques in patients with a transmural rupture of the upper SSC tendon at 2-year follow-up. It was hypothesized that the 2 techniques would not differ significantly in outcomes.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Forty patients with a transmural tear of the upper SSC tendon (grade 2 or 3 according to Fox and Romeo) were retrospectively enrolled. Depending on the repair technique, patients were assigned to either the knotless single-anchor or knotted single-anchor group. After a mean follow-up of 2.33 ± 0.43 years, patients were assessed by the ASES, WORC, OSS, CS, and SSV. A clinical examination that included the bear-hug, the lift-off, and the belly-press tests was performed, in which the force exerted by the subjects was measured. In addition, all patients underwent MRI of the affected shoulder to assess repair integrity, tendon width, fatty infiltration, signal-to-signal ratio of the upper and lower SSC muscle, and atrophy of the SSC muscle.

Results:

No significant difference was found between the 2 groups on any of the clinical scores [ASES (P = .272), WORC (P = .523), OSS (P = .401), CS (P = .328), SSV (P = .540)] or on the range-of-motion or force measurements. Apart from a higher signal-to-signal ratio of the lower SSC muscle in the knotless group (P = .017), no significant difference on imaging outcomes was found between the 2 groups.

Conclusion:

Both techniques can be used in surgical practice, as neither was found to be superior to the other in terms of clinical or imaging outcomes at 2-year follow-up.

Electromyographic Evaluation of Early-Stage Shoulder Rehabilitation Exercises Following Rotator Cuff Repair

BACKGROUND

Electromyography (EMG) is frequently used as a guide for exercise rehabilitation progression following rotator cuff repair. Knowledge of EMG activity during passive and active-assisted exercises may help guide clinicians when considering exercise prescription in the early post-operative period.

PURPOSE

The purpose of this study was to investigate EMG activity of the rotator cuff and deltoid musculature during passive and active-assisted shoulder range of motion (ROM) exercises commonly performed in post-operative rehabilitation.

STUDY DESIGN

Descriptive cohort laboratory study using healthy subjects.

METHODS

In sixteen active healthy volunteers, surface and fine-wire EMG activity was measured in the supraspinatus, infraspinatus, subscapularis, and anterior, middle and posterior deltoid muscles during eight common ROM exercises. Mean %MVIC values and 95% confidence intervals were used to rank exercises from the least to the most amount of muscular activity generated during the exercises.

RESULTS

Standard pendulum exercises generated low levels of EMG activity in the supraspinatus and infraspinatus (≤15% MVIC), while active-assisted table slides, and the upright wall slide generated low levels of EMG activity in only the supraspinatus. No exercises were found to generate low levels of muscular activation (≤15% MVIC) in the subscapularis.

CONCLUSION

This study found no clear distinctions between the EMG activity of the supraspinatus or the infraspinatus occurring during common passive and active-assisted ROM exercises. Subdividing ROM exercises based on muscle activity, may not be necessary to guide progression of exercises prior to commencing active motion after rotator cuff repair.

LEVEL OF EVIDENCE

Level 3b.

Electromyography of the Shoulder Musculature during Passive Rehabilitation Exercises

Background

Medical professionals remain conflicted about the best rehabilitation protocol a patient should perform after rotator cuff repair surgery. Exercises deemed passive may be activating the shoulder muscles to a moderate level, thus putting the surgical repair construct at risk for re-injury. The purpose of this study was to measure the activation of the rotator cuff and surrounding musculature during exercises used in physical therapy following rotator cuff repair surgery using electromyography (EMG).

Methods

Muscle activation was recorded in fourteen participants performing sixteen exercises. Four fine wire electrodes (supraspinatus, infraspinatus, subscapularis, teres minor) and six surface electrodes (upper and middle division of the trapezius, anterior, medial and posterior head of the deltoid, biceps brachii) were utilized. EMG activity values for each muscle were normalized to the maximum voluntary isometric contraction and activation levels were assessed.

Results

Twelve of the sixteen exercises tested were moderately active in the subscapularis muscle. The results show the subscapularis muscle was activated in all three planes of motion.

Discussion

Most exercises were found to have low activation levels for the supraspinatus, infraspinatus and teres minor muscles. While the exercises examined in this study appear to be safe for the more commonly repaired supraspinatus, caution should be used when administering exercises to individuals with repairs involving the subscapularis.

Effectiveness of supervised early exercise program in patients with arthroscopic rotator cuff repair: Study protocol clinical trial

BACKGROUND

Based on the available evidence, it is difficult to make a clinical decision about the best exercise program and to establish the most favorable time to start postoperative treatment after rotator cuff (RC) repair. The aim of this trial is to evaluate the effects of adding a supervised early exercise program to standard treatment for functional improvement and pain relief compared with standard treatment alone in patients with arthroscopic RC repair.

METHOD/DESIGN

A total of 118 patients between the ages of 18 and 50 years with arthroscopic RC repair will be randomized to 2 treatment arms. The control group will receive a standard exercise program based on a consensus statement on shoulder rehabilitation developed by the American Society of Shoulder and Elbow Therapists. The intervention group will receive a supervised early exercise program in combination with standard treatment. This supervised exercise program will be based on electromyographic evidence. Three evaluations will be performed: before surgery, at 6 weeks, and at 12 weeks. The primary outcome measure will be the shoulder function by the Constant-Murley questionnaire, and the secondary outcome measures will be the upper limb function by the disabilities of the arm, shoulder, and hand questionnaire; pain by the visual analog scale; and the shoulder range of motion by a goniometer.

DISCUSSION

We hypothesize that patients who receive a supervised early exercise program in combination with standard treatment will benefit more in respect to shoulder function, pain reduction, and range of motion than those who receive a standard exercise program. If this is confirmed, our study can be used clinically to enhance the recovery of patients with arthroscopic RC repair.

TRIAL REGISTRATION

Brazilian registry of clinical trials UTN number U1111-1224-4143. Registered December 18, 2018.

Clinical and Neurophysiological Changes after Targeted Intrathecal Injections of Bone Marrow Stem Cells in a C3 Tetraplegic Subject

High-level quadriplegia is a devastating condition with limited treatment options. Bone marrow derived stem cells (BMSCs) are reported to have immunomodulatory and neurotrophic effects in spinal cord injury (SCI). We report a subject with complete C2 SCI who received three anatomically targeted intrathecal infusions of BMSCs under a single-patient expanded access investigational new drug (IND). She underwent intensive physical therapy and was followed for >2 years. At end-point, her American Spinal Injury Association Impairment Scale (AIS) grade improved from A to B, and she recovered focal pressure touch sensation over several body areas. We conducted serial neurophysiological testing to monitor changes in residual connectivity. Motor, sensory, and autonomic system testing included motor evoked potentials (MEPs), somatosensory evoked potentials (SSEPs), electromyography (EMG) recordings, F waves, galvanic skin responses, and tilt-table responses. The quality and magnitude of voluntary EMG activations increased over time, but remained below the threshold of clinically obvious movement. Unexpectedly, at 14 months post-injury, deep inspiratory maneuvers triggered respiratory-like EMG bursting in the biceps and several other muscles. This finding means that connections between respiratory neurons and motor neurons were newly established, or unmasked. We also report serial analysis of MRI, International Standards for Neurological Classification of SCI (ISNCSCI), pulmonary function, pain scores, cerebrospinal fluid (CSF) cytokines, and bladder assessment. As a single case, the linkage of the clinical and neurophysiological changes to either natural history or to the BMSC infusions cannot be resolved. Nevertheless, such detailed neurophysiological assessment of high cervical SCI patients is rarely performed. Our findings indicate that electrophysiology studies are sensitive to define both residual connectivity and new plasticity.

[Treatment after anatomical and inverse shoulder TEP]

Shoulder arthroplasties in specialized centers are routine procedures with an increasing number of operations in the developed countries. Restoration of pain free shoulder function requires an intensive, specific and individual rehabilitation program for each patient. There is a phase-like course with different specific demands and measures that extends over a period of several weeks. Return to sport and a pain free function for activities of daily living resulting in a high patient satisfaction can routinely be expected. This excellent perspective, extent and intensity of the rehabilitation program shall be part of the preoperative decision making.

A Systematic Review of Electromyography Studies in Normal Shoulders to Inform Postoperative Rehabilitation Following Rotator Cuff Repair

Study Design Systematic review. Background Electromyography (EMG) has previously been used to guide postoperative rehabilitation progression following rotator cuff repair to prevent deleterious loading of early surgical repair. Objective To review the current literature investigating EMG during rehabilitation exercises in normal shoulders, and to identify exercises that meet a cut point of 15% maximal voluntary isometric contraction (MVIC) or less and are unlikely to result in excessive loading in the early postoperative stages. Methods An electronic search of MEDLINE via Ovid, Embase, CINAHL, SPORTDiscus, PubMed, and the Cochrane Library for all years up to June 2016 was performed. Studies were selected in relation to predefined selection criteria. Pooled mean MVICs were reported and classified as low (0%-15% MVIC), low to moderate (16%-20% MVIC), moderate (21%-40% MVIC), high (41%-60% MVIC), and very high (greater than 60% MVIC). Results A search identified 2159 studies. After applying the selection criteria, 20 studies were included for quality assessment, data extraction, and data synthesis. In total, 43 exercises spanning passive range of motion, active-assisted range of motion, and strengthening exercises were evaluated. Out of 13 active-assisted exercises, 9 were identified as suitable (15% MVIC or less) to load the supraspinatus and 10 as suitable to load the infraspinatus early after surgery. All exercises were placed in a theoretical-continuum model, by which general recommendations could be made for prescription in patients post rotator cuff repair. Conclusion This review identified passive and active-assisted exercises that may be appropriate in the early stages after rotator cuff repair. J Orthop Sports Phys Ther 2017;47(12):931-944. Epub 13 Jul 2017. doi:10.2519/jospt.2017.7271.

Changes in the electromyographic activities of the infraspinatus and posterior deltoid according to abduction angles of the shoulder joint during shoulder external rotation in closed kinetic chain exercise

[Purpose] This study's purpose was to identify abduction angles of the shoulder joint that can provide effective infraspinatus muscle exercises while minimizing the muscle activity of the posterior deltoid muscle. [Subjects and Methods] The subjects of this study were 15 healthy young students in their 20s. Subjects adopted a standing position and performed shoulder external abduction while pushing their hands against the wall. The current research was undertaken to compare the activity of the infraspinatus muscle and the posterior deltoid muscle at abduction angles of 45, 90 and 135° of the shoulder joint during closed kinetic chain exercises. [Results] A activity of the infraspinatus muscle showed no statistically significant differences. The activities of posterior deltoid muscle were greater at the angle of 45° than at 90 and 135°. [Conclusion] These results indicate that to strengthen the infraspinatus, shoulder external rotation exercises at abduction angles of the shoulder joint greater than 45° are more effective.

Electromyographic Activities of the Rotator Cuff Muscles During Walking, Eating, and Washing

OBJECTIVE

The aim of this study was to evaluate the activity of rotator cuff (RC) muscles during activities of daily living.

DESIGN

Motion analysis was conducted with 14 volunteers. Activation of RC (subscapularis, supraspinatus, and infraspinatus) was assessed using electromyography (EMG). Walking was performed with or without a shoulder immobilizer. Eating was conducted with or without the support of the elbow with the contralateral hand. Washing the hair was simulated while standing or leaning forward; washing the body was simulated while standing or holding the elbow; and washing the face was simulated using both hands while leaning forward.

RESULTS

During walking, RC's peak EMG activities remained below 7% maximum voluntary isometric contraction at all times, regardless of the use of immobilizers. Eating caused mild EMG activities (14%-32%), whereas eating with elbow support resulted in significantly lower EMG activities in the supraspinatus and infraspinatus. Washing the hair standing moderately activated RC (23%-57%), whereas leaning forward decreased it to 6% to 36%. Washing the body while holding the elbow decreased infraspinatus activation to 4% from 10% when standing. Washing the face with both hands and leaning forward resulted in high-peak EMG activities in the upper subscapularis (37%).

CONCLUSIONS

There was no difference in RC activity level between walking with or without immobilizers. From the point of muscle contraction, an immobilizer is not mandatory. Holding the elbow with the contralateral hand while eating or washing can help decrease the load in the supraspinatus and infraspinatus.

Are Pulley Exercises Initiated 6 Weeks After Rotator Cuff Repair a Safe and Effective Rehabilitative Treatment? A Randomized Controlled Trial

BACKGROUND

There are few level 1 or 2 evidence studies that examine rehabilitation after rotator cuff repair. Pulleys have been used in postoperative shoulder rehabilitation with the intention of improving range of motion and developing strength. There is a concern that the use of pulleys in rehabilitation of rotator cuff repairs may contribute to excessive scapular motion (scapular substitution) and potentially inferior outcomes.

HYPOTHESIS

Rotator cuff repair patients treated with pulley exercises would have increased scapular substitution and inferior patient-determined outcome scores, range of motion, and strength compared with patients treated with an alternative rehabilitation program without pulleys.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 27 patients who underwent rotator cuff repair were randomized to a rehabilitation group that used pulleys initiated 6 weeks postoperatively, and 26 patients followed a rehabilitation protocol without pulleys. Inclusion criteria were patients undergoing arthroscopic rotator cuff repair. Exclusion criteria were large to massive rotator cuff tears, revision rotator cuff repair, glenohumeral osteoarthritis, adhesive capsulitis, and a symptomatic contralateral shoulder. Outcomes of intervention were patient-determined outcome scores (Western Ontario Rotator Cuff Index [WORC], American Shoulder and Elbow Surgeons [ASES] Shoulder Score, Single Assessment Numeric Evaluation [SANE], Shoulder Activity Level, and Simple Shoulder Test [SST]), range of motion, scapular substitution, and strength. Outcomes were determined at 6, 12, 18, 26, and 52 weeks. A power analysis determined that 22 patients were needed per group to have a power of 0.80, α = 0.05, and effect size of f = 0.5.

RESULTS

Both groups had statistically significant improvements in WORC, ASES Shoulder Score, SST, and SANE scores over time after rotator cuff repair (P < .0001). There were no differences between the interventions for WORC (P = .18), ASES Shoulder Score (P = .73), SANE (P = .5), Shoulder Activity Level (P = .39), or SST (P = .36). Both interventions demonstrated improvements in shoulder flexion (P = .002), abduction (P = .0001), external rotation (P = .02), strength (P ≤ .0002), and scapular substitution (P ≤ .07) over time after rotator cuff repair. However, there was no difference in range of motion (P ≥ .26), strength (P ≥ .20), or scapular substitution (P ≥ .17) between interventions.

CONCLUSION

A rotator cuff repair rehabilitation program that uses pulleys does not result in inferior outcomes, as determined by patient-determined outcome scores, measurements of scapular substitution, range of motion, and scaption strength.

REGISTRATION

ClinicalTrials.gov NCT01819909.