Shoulder Abduction Angle Research Articles

Application of the Coupling Angle to Investigate Upper Limb Interjoint Coordination After Stroke

ObjectiveInterjoint coordination after stroke is affected, which limits the use of the upper limb. Current methods to determine interjoint coordination lack the ability to visualize and quantify the movement. Therefore we investigated if the coupling angle can be used to visualize and interpret upper limb interjoint coordination following a stroke. MethodsSeven chronic stroke patients trained six weeks with an assistive home-training system (MERLIN). Kinematic outcomes, i.e. elbow and shoulder range of motion, movement duration, and angle-angle plots were determined in a retrieving task. Interjoint coordination between elbow flexion and shoulder abduction angles was expressed as the coupling angle phases and the number of phase transitions: proximal/distal joint leading phase, in-phase and anti-phase. Comparisons were made within sides: pre-test versus post-test, and between sides: most-affected (MA) versus least-affected (LA). ResultsSmaller elbow flexion angles were found PreMA versus PreLA, and smaller shoulder abduction angles in PostMA versus PostLA. A general coordination pattern was revealed on the LA side, but not on the MA side. A trend showed less phase transitions at the MA side after training, suggesting a smoother movement. Quantification of the movement phases indicated more involvement of the shoulder joint involvement in the MA side during pre-test. After training, these differences were not apparent, which might reveal an increased independent control of the elbow joint. ConclusionsThe coupling angle and the movement phases provide a promising tool to investigate post-stroke interjoint coordination patterns. SignificanceA new visualisation of the interjoint coordination may benefit rehabilitation of stroke survivors. RegistrationThis trial was registered at the Netherlands Trial Register (NL7535) https://www.trialregister.nl/trial/7535.

Post Hoc Subgroup Analysis of the BCause Study Assessing the Effect of AbobotulinumtoxinA on Post-Stroke Shoulder Pain in Adults.

Botulinum toxin type A is approved for the focal treatment of spasticity; however, the effectiveness of abobotulinumtoxinA (aboBoNT-A) in patients with shoulder pain who have set reduced pain as a treatment goal is understudied. In addition, some patients encounter delays in accessing treatment programs; therefore, the suitability of aboBoNT-A for pain reduction in this population requires investigation. These factors were assessed in aboBoNT-A-naive Brazilian patients in a post hoc analysis of data from BCause, an observational, multicenter, prospective study (NCT02390206). Patients (N = 49, n = 25 female; mean (standard deviation) age of 60.3 (9.1) years; median (range) time since onset of spasticity of 16.1 (0-193) months) received aboBoNT-A injections to shoulder muscles in one or two treatment cycles (n = 47). Using goal attainment scaling (GAS), most patients achieved their goal of shoulder pain reduction after one treatment cycle (72.1%; 95% confidence interval: 57.2-83.4%). Improvements in GAS T-score from baseline, clinically meaningful reductions in pain score at movement, and clinically meaningful increases in passive shoulder abduction angle further improved with repeated treatment more than 4 months later, despite treatment starting at a median of 16.1 months after the onset of spasticity. These findings support the further investigation of aboBoNT-A injections in chronic post-stroke shoulder pain.

The effect of bench press technique variations in grip width, shoulder abduction angle and scapula pose on musculoskeletal shoulder loads and injury risk

Introduction: Shoulder injuries as result of the bench press exercise are commonly reported, including rotator cuff impingement, osteolysis of the distal clavicle, glenohumeral instability and pectoralis major rupture. While a large body of research has investigated bench press techniques in relation to optimal performance, no biomechanical evidence regarding the bench press technique with the lowest injury risk is available. Therefore, the aim of the present study was to compare musculoskeletal shoulder loads during several variations of the bench press exercise.

Reliability of Upper Limb Neurodynamic Tests: Median, Radial, and Ulnar Nerves

Objective Upper limb neurodynamic tests are used to evaluate the mechanical sensitivity of the peripheral nerves. However, very little is known about the reliability of upper limb neurodynamic tests, especially for the radial and ulnar nerves. This study aimed to evaluate the reliability of neurodynamic tests of the upper extremities to test median, radial, and ulnar nerves. Materials & Methods In this observational cross-sectional study, 25 asymptomatic subjects aged 19-45 years participated. They were selected using simple non-random sampling. Then two examiners performed the neurodynamic tests on them on two successive days. The goal was to assess the reliability of median, radial, and ulnar neurodynamic tests. During the neurodynamic tests, the participants reported the initial stretching pain and the moment of submaximal pain (substantially obvious pain) in related areas of the nerve distribution, including the anterior side of the elbow and forearm for the median nerve, posterolateral aspect of the elbow and forearm for radial nerve, and medial side of elbow and forearm for the ulnar nerve. At the starting point of painful stretching and the submaximal pain, the angle of elbow extension (for median and radial nerve tests) and shoulder abduction angle (for ulnar nerve test) were measured using a mechanical goniometer. The range between these two points was used to analyze the reliability. The intraclass correlation coefficient (ICC) and the standard error of measurement (SEM) were calculated to examine the relative and absolute reliability, respectively. Using t-test, the difference in the mean of the measurements was calculated. Results No significant difference was found between the mean measurements of the two testers in intra-session and inter-session reliability. For examiners 1 and 2, was obtained 0.94 (SEM:2ο) and 0.89 (SEM:2.85ο) for the median nerve, 0.56 (SEM:6.36˚ ) and 0.93 (SEM:1.82ο) for radial nerve, and 0.42 (SEM:3.27ο) and 0.79 (SEM:1.42ο) for the ulnar nerve. Inter-tester intra-session reliability was obtained at 0.84 (SEM: 3.44ο), 0.54 (SEM: 6.1ο), and 0.55 (SEM: 2.75ο), respectively, for median, radial, and ulnar nerves. Inter-tester inter-session reliability was obtained at 0.97 (SEM:1.43ο), 0.69 (SEM:5.06ο), and 0.51 (SEM: 2.8˚ο), respectively, for median, radial, and ulnar nerves. Conclusion The upper limb neurodynamic tests and measurement of the range between the onset of stretching pain and the point of submaximal pain have moderate to excellent reliability. Therefore, these clinical tests can be used in diagnostic evaluations and treatment interventions. Also, the median nerve neurodynamic test has higher relative reliability than radial and ulnar nerve neurodynamic tests.

Providing safe and effective rehabilitation by assessing supraspinatus muscle elasticity using ultrasound real-time tissue elastography after rotator cuff repair: A case series

ABSTRACT Introduction Although surgical techniques have advanced to avoid a postoperative re-tear after rotator cuff surgery, it remains unclear how to directly evaluate the risk of a re-tear. Objective To describe how muscle elasticity with real-time tissue elastography could be used to avoid re-tear in individual cases after rotator cuff repair. Case Description This case series included four patients, two per tear size (small and large/massive), with contrasting changes in muscle elasticity of the supraspinatus muscle. All patients underwent primary arthroscopic or open rotator cuff repair. The elasticity of the supraspinatus muscle was evaluated at relaxed and elongated positions of 0° and 60° shoulder abduction angles, respectively. The change in muscle elasticity at 1 month after surgery was characteristically different, and we predicted that a greater elasticity in the elongated position indicated a higher risk of re-tear. The cases with high risk underwent careful rehabilitation to avoid re-tear, and no re-tears were recorded in this report. Conclusion Our findings suggested that evaluation of muscle elasticity using real-time tissue elastography, which provides an indication of the risk of re-tear, in the clinical setting might be useful for therapists, who could adjust the intensity of rehabilitation, and for patients.

Reliability and Validity of the Athletic Shoulder (ASH) Test Performed Using Portable Isometric-Based Strength Training Device.

Simple SummaryThe Athletic Shoulder (ASH) test was developed to quantify force across the shoulder girdle in athletes for diagnosis and monitoring. Initially, this test was performed using force plates. The question remains whether force plates may be replaced with a more feasible tool for field testing, such as an isometric-based strength training device. Hence, the present study determined whether Active5™ may be an alternative to force plates for ASH test purposes. Consequently, the ASH test was performed on different days by the same rater and different raters using Active5™ and K-Force plates. It was also checked whether the test results obtained using various tools correlated with each other. The study indicated that both devices were reliable tools, and the ASH test results obtained with the use of the two devices were largely correlated with each other.The Athletic Shoulder (ASH) test was introduced as a tool for quantifying the ability to produce and transfer force across the shoulder girdle. Whether using the portable isometric-based strength training device Active5™ is a reliable alternative to a gold standard force plate for ASH testing purposes remains unknown; therefore, the present study determined the reliability and validity of Active5™ usage in the ASH test compared to force plates. Fifty-one healthy participants performed the ASH test using Active5™ and K-Force plates in three separate sessions. The maximal force was measured bilaterally in a prone position at three shoulder abduction angles, precisely at 180°, 135°, and 90°. The first rater carried out the first and third sessions, spaced at a one-week interval. A second rater performed the second session. The reliability was assessed using the intraclass correlation coefficient (ICC). The linear Pearson’s correlation coefficient (r) calculation was used to determine the relationship between ASH test results using the two devices. The ICC = 0.77–0.99 result indicated good to excellent reliability for Active5™ usage. A high to a very high correlation between the two devices at 180° and 90° was noted (r = 0.75–0.95). This data supports the isometric-based strength training device Active5™ as a reliable and valid tool for ASH test performance.

Acromiohumeral distance quantification during a variety of shoulder external and internal rotational exercises in recreationally overhead athletes

ABSTRACT To determine whether shoulder external (ER) and internal rotational (IR) exercises at five different shoulder abduction angles affect the acromiohumeral distance (AHD). Twenty recreational overhead athletes were included. AHD was measured using real-time ultrasound for each of the five shoulder conditions as follows: neutral shoulder rotation (active-hold) and during ER and IR exercises (isometric and concentric) at five different shoulder-abduction angles (0°, 30°, 45°, 60°, and 90° of abduction). A two-way ANOVA was used to analyze AHD values. Shoulder abduction angle × exercise interaction for AHD was found (F16,304 = 10.92; p < .001; η2 = 0.37). For both isometric and concentric conditions, AHD increased during IR exercises (p < .05) yet decreased during ER exercises (p < .05) when compared with each active-hold positions. Shoulder ER and IR exercises influence the AHD in recreational overhead athletes. A larger AHD was observed during shoulder IR exercises, whereas ER exercises failed to maintain the AHD.

Treatment of Medial Shoulder Joint Instability by Stabilization with an Arthroscopically Guided Prosthetic Ligament: A Cadaveric Feasibility Study in Dogs.

The aim of this study was to assess the feasibility and efficiency of an arthroscopically guided ligamentoplasty of the medial glenohumeral ligament to treat medial shoulder joint instability. Six Beagle cadavers were used (12 limbs). Both arms of the medial glenohumeral ligament were severed using arthroscopic guidance. Arthroscopically guided reconstruction of the ligament was performed. Threaded sutures were fixed with a bone anchor on the medial aspect of the glenoidal cavity of the scapula, passed through a humeral tunnel and finally tensioned with a suture button on lateral aspect of the humerus. Shoulder abduction angles were measured before and after the section of the medial glenohumeral ligament, and following the surgery. Two orthogonal radiographic projections and dissections were performed after each procedure to grade the placement of the implants. Surgical repairs were achieved in 10 out of 12 limbs. The abduction angles after repair with ligamentoplasty were not significantly different from the abduction angles measured before the section of the medial glenohumeral ligament. Arthroscopically guided ligamentoplasty with a scapular bone anchor and a humeral drilling tunnel is feasible in cadavers, and efficient to restore acutely shoulder abduction angle in a minimally invasive manner. Further clinical studies are required to assess in vivo results.

Comparative accuracy of a shoulder range motion measurement sensor and Vicon 3D motion capture for shoulder abduction in frozen shoulder

BACKGROUND: Although patients with frozen shoulders have the range of motion (ROM) of their shoulder’s abduction movements measured at hospital and the physical therapy visits, multiple visits to check for progress is often difficult. Thus, we developed an artificial intelligence-based image recognition detectable sensor (AIRDS) intended for easy use at home.OBJECTIVE: The purpose of this study was to determine the accuracy of a sensor (AIRDS) measuring shoulder abduction angle, thus offering a valid and feasible system for monitoring patients with frozen shoulder.METHODS: Ten patients with frozen shoulder (5 males, 5 females) performed shoulder joint movements while being measured with the AIRDS system and the 3-dimensional Vicon system. The measure of the outcome included the linear regression of the shoulder abduction joint kinematics.RESULTS: Linear regression analysis of the AIRDS system and the Vicon system demonstrated a significant correlation coefficient of 0.9979 ( 0.05).CONCLUSIONS: Our results provide novel, promising evidence that AIRDS can accurately measure the timing and total spatial characteristics of clinical movements. AIRDS is designed to provide real-time ROM measurements for joint mobility using artificial intelligence instead of the judgement of the physical therapist.

Functional outcome of contralateral C7 nerve transfer combined with free functional gracilis transplantation to repair total brachial plexus avulsion: a report of thirty-nine cases

PurposeTreatment of total brachial plexus avulsion (TBPA) is a challenge in the clinic, especially the restoration of hand function. The current main surgical order is from proximal to distal joints. The purpose of this study was to demonstrate the outcomes of “distal to proximal” surgical method.MethodsThirty-nine patients underwent contralateral C7 (CC7) nerve transfer to directly repair the lower trunk (CC7-LT) and phrenic nerve transfer to the suprascapular nerve (PN-SSN) during the first stage, followed by free functional gracilis transplantation (FFGT) for elbow flexion and finger extension. Muscle strength of upper limb, degree of shoulder abduction and elbow flexion, and Semmes–Weinstein monofilament test and static two-point discrimination of the hand were examined according to the modified British Medical Research Council (mBMRC) scoring system.ResultsThe results showed that motor recovery reached a level of M3 + or greater in 66.7% of patients for shoulder abduction, 87.2% of patients for elbow flexion, 48.7% of patients for finger extension, and 25.6% of patients for finger flexion. The mean shoulder abduction angle was 45.5° (range 0–90°), and the average elbow flexion angle was 107.2° (range 0–142°), with 2.5 kg average flexion strength (range 0.5–5 kg). In addition, protective sensibility (≥ S2) was found to be achieved in 71.8% of patients.ConclusionIn reconstruction of TBPA, CC7 transfer combined with free functional gracilis transplantation is an available treatment method. It could help patients regain shoulder joint stability and the function of elbow flexion and finger extension and, more importantly, provide finger sensation and partial finger flexion function. However, the pick-up function was unsatisfied, which needed additional surgery.

Evaluation of supraspinatus muscle changes in the shoulder joint of stroke patients with hemiplegic and shoulder subluxation using ultrasonography: comparison between affected and unaffected sides.

[Purpose] The shoulder joint has a very unstable structure yet a significantly wide range of motion. Weakness of the muscles around the shoulder joint may cause shoulder joint subluxation. This study aimed to determine changes in supraspinatus muscle thickness between different shoulder abduction angles using ultrasonography and to compare differences in supraspinatus muscle thickness changes between the affected and unaffected sides depending on shoulder joint subluxation. [Participants and Methods] Forty hemiplegic patients with stroke were recruited (20 patients with and 20 without shoulder subluxation). Using ultrasonography, we measured supraspinatus muscle thickness at three shoulder joint abduction angles and calculated the differences in supraspinatus muscle thickness. Depending on subluxation, we separately analyzed the thickness and variations in the supraspinatus muscle on both the affected and unaffected sides. [Results] In stroke patients with shoulder subluxation, the difference in supraspinatus muscle thickness was significantly less in the affected side than in the unaffected side. [Conclusion] The thickness and rate of supraspinatus muscle thickness change was significantly less in the affected side than in the unaffected side in stroke patients with shoulder subluxation.

Measurement of Stiffness of Supraspinatus Tendon Using Ultrasound Elastography

The supraspinatus tendon (SSPT) is a tendon connected the supraspinatus muscle to the greater tuberosity of the glenohumeral joint and acts during shoulder abduction. The SSPT is known to be the most frequently injured tendon in the rotator cuff, and repetitive movements and age-related muscle weakness are the most common causes of injury. The mechanical properties of the SSPT are important not only for the diagnosis of damaged tendons, but also for the evaluation after rotator cuff repair. The aim of this study was to evaluate the stiffness of the SSPT in vivo by shoulder abduction and muscle contraction using ultrasound elastography. This study showed that the stiffness of each part of the SSPT decreased as the shoulder abduction angle increased.

Outcome comparison between thoracodorsal artery perforator flap and muscle-sparing latissimus dorsi flap in axillary reconstruction after hidradenitis suppurativa excision.

Thoracodorsal artery perforator (TDAP) flap and muscle-sparing latissimus dorsi (MSLD) flap have been frequently used for axillary coverage after hidradenitis suppurativa (HS) excision. However, none showed superiority to others. This study compared both flaps to define the ideal option, highlighting flap outcomes and functional and aesthetic results. A retrospective study was conducted to compare both flaps that were used for axillary reconstruction in nine patients with bilateral HS Hurley stage III between 2017 and 2020. Eight TDAP and 10 MSLD flaps underwent functional evaluation using shoulder abduction angle (SA); the Disabilities of the Arm, Shoulder, and Hand (DASH) score; visual analog scale (VAS) for pain; and the Dermatology Life Quality Index (DLQI) questionnaires. Aesthetic assessment included the Scar Cosmesis Assessment and Rating (SCAR) scale and arm-chest interval. The mean operating time was 194.4 ± 51.58 and 128.5 ± 31.45 min for TDAP and MSLD (p =.009), respectively. Flap complications were significantly higher in the TDAP group (p =.034). There was no significant difference between both groups regarding SA; DASH, DLQI, VAS, and SCAR scale (p > .05). The mean arm-chest interval was significantly longer in the MSLD than in the TDAP group by 6.9 mm (p =.001). TDAP and MSLD are comparable versatile flaps to eradicate axillary HS with higher TDAP flap complications. Although the TDAP flap is less bulky than the MSLD flap, the MSLD flap shortens the harvesting time without a significant difference in functional outcomes and scar results.

The Effect of Shoulder Abduction Angle on Trapezius Muscle Activity During Scapular Retraction Exercise.

Scapular retraction exercises are often prescribed to enhance scapular stabilization. To investigate the upper trapezius (UT), middle trapezius (MT), lower trapezius (LT) activities, and UT/MT and UT/LT ratios during scapular retraction exercise with elastic resistance at different shoulder abduction angles. Descriptive laboratory study. Biomechanical analysis laboratory. Thirty-five asymptomatic individuals. Surface electromyography was used to evaluate UT, MT, and LT activities during the scapular retraction exercise at 0º, 45º, 90º, and 120º shoulder abductions. The mean muscle activity ranged from 15.8%-54.7% maximum voluntary isometric contraction (MVIC) for UT, 30.5%-51.6% MVIC for MT, 21.4%-25.5% MVIC for LT. A significant "muscle×angle" interaction was found (p<0.001). Post hoc analysis revealed that the MT was significantly more activated than UT and LT during both retraction at 0º (p<0.001; p=0.01, respectively) and 120º (p=0.03; p=0.002, respectively). During retraction at 45º and 90º, the LT generated significantly lower activity than the UT (p=0.02; p=0.03, respectively) and MT (p<0.001; p=0.002, respectively). Besides, UT/MT and UT/LT ratios during retraction at 0º were significantly lower than 45º (p=0.03; p=0.001, respectively) and 90º (p<0.001; p<0.001, respectively). Retraction at 90º resulted significantly higher UT/LT ratio than 45º (p=0.004) and 120º (p=0.004). Due to lower UT activity relative to MT, retraction at 0º, 45º, and 120º can be preferred in early shoulder training or rehabilitation. Additionally, retraction at 90º was the most effective exercise in activating entire trapezius muscle parts.

Adjustment effect during shoulder abduction training with the Hybrid Assistive Limb in a patient with postoperative C5 palsy

Standard shoulder rehabilitation procedures for patients with postoperative C5 palsy have not yet been established. We applied a wearable robot suit hybrid assistive limb (HAL) for a patient with postoperative C5 palsy and conducted shoulder abduction training with HAL. A 65-year-old woman was diagnosed with postoperative C5 palsy after undergoing cervical spine surgery. Five days after surgery, shoulder abduction training with HAL was initiated. The shoulder abduction angle and power and trapezius and deltoid activities were evaluated. Ten rehabilitation sessions were conducted until 82 days after surgery. Shoulder abduction training was safely and effectively performed from the first session. Her shoulder abduction angle and power improved at every session, and she could fully elevate her arm without any compensatory motion after the 10th session. Shoulder HAL training suppressed the muscular activity of the trapezius and activated that of the deltoid, especially in the earlier stages of rehabilitation. Moreover, it had an adjustment effect for obtaining normal shoulder motion, which might have promoted smoother arm elevation using errorless motor learning. These findings suggest that HAL is a useful tool for shoulder rehabilitation in patients with postoperative C5 palsy.

Design and clinical application of a combined shoulder abduction orthosis for post-burn treatment

Cicatricial contracture is likely to occur at the deep burn wound under the armpits after healing, which results in limitation of shoulder abduction and seriously affects the function of upper limbs of patients. Wearing shoulder abduction orthosis is an effective intervention method for cicatricial contracture under the armpits, but the adjustable shoulder abduction orthosis commonly used clinically at present is limited in the adjustable range, and the customized static orthosis can only maintain the corresponding angle of shoulder abduction. Besides, the above two orthosis can only have the function of unilateral extention, and they are time-consuming for patients with need of bilateral extension. Aiming at the problems mentioned above, a combined shoulder abduction orthosis was designed by the Tongren Hospital of Wuhan University & Wuhan Third Hospital. The low temperature thermoplastic sheet was cut, shaped, and assembled according to the patient's measurement data of abdomen, upper arm, and lumbar to prepare the combined shoulder abduction orthosis. This abduction orthosis can not only extend the cicatrix contracture under the armpits progressively and extensively, so as to effectively prevent the cicatricial contracture under the armpits, but also can select unilateral or bilateral extension based on the contracture limits for shoulder abduction, thus saving time for both medical workers and patients in relevant treatment.

The Effect of a Corrective Exercise Program Based on Scapula Stability on Scapular Upward Rotation and Scapulohumeral Rhythm in Wheelchair Basketball Athletes With Bilateral Scapula Rotational Syndrome

Objective The present study aimed to investigate the effect of scapular stability-based corrective exercise program on scapular upward rotation and scapulohumeral rhythm in Wheelchair Basketball (WB) players with bilateral scapular downward rotation syndrome. Materials &amp; Methods: According to the research conditions, 24 wheelchair basketball athletes with spinal cord injury voluntarily participated in this study. Initially, eight players were selected from each sport class (1 to 1.5 class, 2 to 2.5 class, and 3 to 4.5 class). Then, four subjects in each group were randomly assigned to each group (12 control subjects with Mean±SD age of 43.23±11.0 years and 12 experimental subjects with Mean±SD age of 39.08±5.08 years). Thus, the control and experimental groups were present in an equal number of three sport classes. WB athletes were professional players in Mashhad City league, Iran. The participants were classified according to the Classification Committee of the IWBF, as well as the corresponding national classification from the Islamic Republic of Iran Sports Federation for the Disabled (IRISFD). Two digital inclinometers were used to measure the humeral range of motion and scapular upward rotation and scapulohumeral rhythm in resting position, 45°, 90°, and 135° shoulder abduction in scaption plane. The exercise group performed scapular stability-based corrective exercises based on the Gym training principles and following ACSM guidelines for eight weeks. The independent t-test, analysis of variance, and analysis of covariance were used for statistical analysis at the significant level of less or equal to 0.05. Results: The results showed no significant asymmetry between dominant and non-dominant shoulders in the scapula’s upward rotation at different angles of shoulder abduction. Contrary to the non-dominant shoulder, the dominant shoulder’s scapula had a less downward rotation at the resting position and a higher upward rotation at 45° of shoulder abduction. Also, in 45° humeral abduction, the dominant shoulder has a less scapulohumeral rhythm ratio than the non-dominant shoulder. WB athletes’ dominant shoulders in lower classes (2-2.5 and 3-4.5) have less scapular downward rotation in scapular resting position and more scapular upward rotation in 45°, 90° 135° humeral abduction. There was no significant difference in scapulohumeral rhythm ratio between WB players with different classes. Scapular upward rotation increased significantly after eight weeks of scapular stability-based corrective exercise program (P≤0.05). Also, a significant decrease in the scapular upward rotation was observed at post-program in resting position (P=0.001) and significantly increased in 45° (P=0.01), 90° (P=0.001), and 135° (P=0.001) humeral abduction compared with pre-program in dominant and non-dominant shoulders. However, the ratio of scapulohumeral rhythm in the dominant shoulder did not improve significantly, and the ratio of scapulohumeral rhythm in the non-dominant shoulder improved at 90° and 135°. Conclusion: Scapular stability-based corrective exercises can be used as one of the training methods to restore muscle balance, prevent and correct scapular upward rotation and scapulohumeral rhythm in wheelchair basketball athletes. Therapists should know that some degrees of scapular upward rotation and scapulohumeral rhythm asymmetry may be common in WB players. This asymmetry should not always be considered a pathological symptom but may be an adaptation to exercise training and frequent use of the upper extremity.

Evaluation of Hologram Distances in Reducing Shoulder Stress During Augmented Reality Interactions

This study investigated the effect of different hologram distances on the shoulder postures, muscle activities, and the task performance (speed) during Augmented Reality (AR) interactions. With a repeated- measures design, 20 participants (10 males) performed the 3-D cube task involving gaze, pinching, and dragging gestures by different hologram distances: near (30 cm), middle (60 cm), and far (90 cm) relative to the participant. Meanwhile, muscle activities (upper trapezius, anterior and middle deltoid) and the right shoulder postures were measured. The results showed that hologram distances significantly affected middle deltoid muscle activities and shoulder flexion and abduction angles, and task performance during 3-D cube task ( p’s &lt; 0.001). The far hologram distance resulted in higher middle deltoid muscle activity and shoulder angles compared to the near and middle distances. Task performance was higher when the hologram was displayed in the middle compared to the near and far distances ( p’s &lt; 0.001). These results indicate that a hologram distance may be an important design factor affecting users’ shoulder stress and task performance during AR interactions.

Effect of Shoulder Abduction Angles on EMG Activity of the Abdominal Muscles during Single Leg Holding on the Foam Roller

Purpose: This study examined the electromyography (EMG) activity of the abdominal muscles and the ratio of the oblique abdominal muscle activity to the rectus abdominis muscle during a single-leg holding position with isometric shoulder abduction (SLHISA) in the supine position on a foam roller. Methods: Nineteen healthy males were recruited to the study. Each subject was asked to lay on a round foam roller and perform single-leg (nondominant) holding with contralateral shoulder abduction to one of three angles (45°, 90°, or 135°) in random order. The surface EMG signals of the bilateral rectus abdominis (RA), external oblique abdominis (EO), and combined internal oblique abdominis (IO) and transverse abdominis (TrA) muscle were collected during the tasks. The EO/RA and (IO & TrA)/RA ratios were determined using surface EMG. One way repeated measure ANOVA with three SLHISAs was used to assess the significant abdominal muscle EMG activity and the ratio of the oblique abdominal muscles activity to the RA muscle. The statistical significance level was p<0.05. Results: The results were as follows. The SLHISA 135° showed significantly higher EMG activity of both RAs, left EO, and right IO & TrA muscles (p<0.05). The right EO and left IO and TrA muscles/RA were significantly different among the SLHISA angles. The SLHISA 45° showed a significantly greater ratio of right EO/RA and left IO & TrA/RA (p<0.05). Conclusion: SLHISA on a foam roller is useful for lumbopelvic stabilization exercise by increasing the activity and recruiting a specific pattern of the oblique abdominal muscle.

Shoulder function after neck dissection: Assessment via a shoulder-specific quality-of-life questionnaire and active shoulder abduction

ObjectiveNeck dissection results in a high probability of postoperative shoulder functional impairment, even when the spinal accessory nerve is preserved. Therefore, surgeons must inform patients about the expected functional and qualitative recovery of shoulder function after surgery. MethodsThe present study included a prospective cohort of 66 patients (85 neck dissection sides) who underwent neck dissection between December 2015 and July 2017 at a single institution. The active shoulder abduction angles of the affected side and the patient-reported shoulder-specific quality-of-life recovery score of the Western Ontario Rotator Cuff (WORC) questionnaire were examined at 1, 3, 6, 9, and 12 months postoperatively. Additionally, the association between these outcomes and risk factors for shoulder impairment were investigated. ResultsThe average active shoulder abduction angles were significantly improved at 3 and 6 months postoperatively compared with 1 month postoperatively (96.5 ± 4.3° at 1 month versus 110.1 ± 4.7° at 3 months, p = 0.035, and versus 142.0 ± 4.6° at 6 months, p < 0.0001). The proportion of patients who were unable to abduct their shoulders by 150° or more was significantly lower at 6 months postoperatively (41.5%) compared with 1 month postoperatively (82.4%, p < 0.0001). The WORC score significantly improved from 60.4 ± 2.4% at 1 month postoperatively to 67.9 ± 2.6% at 6 months postoperatively (p = 0.036). Multivariate analysis revealed that postoperative radiotherapy was a significant risk factor for shoulder impairment at 3 and 6 months postoperatively (p = 0.003 and p = 0.027, respectively), and that level V dissection and head and neck irradiation were significant risk factors for a worse shoulder outcome at 6 and 9 months postoperatively (respective p values for level V dissection and head and neck irradiation were p = 0.049 and p = 0.030 at 6 months postoperatively, and p = 0.016 and p = 0.013 at 9 months postoperatively). ConclusionSatisfactory functional and qualitative recovery of shoulder function was achieved at 6 months after neck dissection. Postoperative radiotherapy was a predictor of poor shoulder function in the early postoperative period; both level V dissection and head and neck irradiation were predictors of poor shoulder function at 6 and 9 months after neck dissection.