Aims: To evaluate the extent to which publication of high-quality randomised controlled trials(RCTs) in 2018 was associated with a change in volume or trend of subacromial decompression(SAD)... Show moreAims: To evaluate the extent to which publication of high-quality randomised controlled trials(RCTs) in 2018 was associated with a change in volume or trend of subacromial decompression(SAD) surgery in patients with subacromial pain syndrome(SAPS) treated in hospitals across various countries. Methods: Routinely collected administrative data of the Global Health Data@work collaborative were used to identify SAPS patients who underwent SAD surgery in six hospitals from five countries (Australia, Belgium, Netherlands, United Kingdom, United States) between 01/2016 and 02/2020. Following a controlled interrupted time series design, segmented Poisson regression was used to compare trends in monthly SAD surgeries before(01/2016-01/2018) and after(02/2018-02/2020) publication of the RCTs. The control group consisted of musculoskeletal patients undergoing other procedures. Results: A total of 3.046 SAD surgeries were performed among SAPS patients treated in five hospitals; one hospital did not perform any SAD surgeries. Overall, publication of trial results was associated with a significant reduction in the trend to use SAD surgery of 2% per month (Incidence rate ratio (IRR) 0.984[0.971-0.998]; P = 0.021), but with large variation between hospitals. No changes in the control group were observed. However, publication of trial results was also associated with a 2% monthly increased trend (IRR 1.019[1.004-1.034]; P = 0.014) towards other procedures performed in SAPS patients. Conclusion: Publication of RCT results was associated with a significantly decreased trend in SAD surgery for SAPS patients, although large variation between participating hospitals existed and a possible shift in coding practices cannot be ruled out. This highlights the complexities of implementing recommendations to change routine clinical practice even if based on high-quality evidence. Show less
Geurkink, T.H.; Overbeek, C.L.; Marang-van de Mheen, P.J.; Nagels, J.; Nelissen, R.G.H.H.; Groot, J.H. de 2023
Purpose: This study aimed to quantify the extent to which age was associated with joint position sense (JPS) of the asymptomatic shoulder as measured by joint position reproduction (JPR) tasks and... Show morePurpose: This study aimed to quantify the extent to which age was associated with joint position sense (JPS) of the asymptomatic shoulder as measured by joint position reproduction (JPR) tasks and assess the reproducibility of these tasks. Methods: 120 Asymptomatic participants aged 18-70 years each performed 10 JPR-tasks. Both contralateral and ipsilateral JPR-tasks were evaluated on accuracy of JPR under active-and passive conditions at two levels within the shoulder forward flexion trajectory. Each task was performed three times. In a subgroup of 40 participants, the reproducibility of JPR-tasks was assessed one week after initial measurement. Reproducibility of JPR-tasks was evaluated by both reliability (intra-class correlation coefficients (ICC's)) and agreement (standard error of measurement (SEM)) measures. Results: Age was not associated with increased JPR-errors for any of the contralateral or ipsilateral JPR-tasks. ICC's ranged between 0.63 and 0.80 for contralateral JPR-tasks, and from 0.32 to 0.48 for ipsilateral tasks, except for one ipsilateral task where the reliability was similar to contralateral tasks (0.79). The SEM was comparable and small for all JPR-tasks, ranging between 1.1 and 2.1. Conclusion: No age-related decline in JPS of the asymptomatic shoulder was found, and good agreement between test and re-test measurements for all JPR-tasks as indicated by the small SEM. Show less
Geurkink, T.H.; Overbeek, C.L.; Marang-van de Mheen, P.J.; Nagels, J.; Nelissen, R.G.H.H.; Groot, J.H. de 2023
PurposeThis study aimed to quantify the extent to which age was associated with joint position sense (JPS) of the asymptomatic shoulder as measured by joint position reproduction (JPR) tasks and... Show morePurposeThis study aimed to quantify the extent to which age was associated with joint position sense (JPS) of the asymptomatic shoulder as measured by joint position reproduction (JPR) tasks and assess the reproducibility of these tasks.Methods120 Asymptomatic participants aged 18–70 years each performed 10 JPR-tasks. Both contralateral and ipsilateral JPR-tasks were evaluated on accuracy of JPR under active- and passive conditions at two levels within the shoulder forward flexion trajectory. Each task was performed three times. In a subgroup of 40 participants, the reproducibility of JPR-tasks was assessed one week after initial measurement. Reproducibility of JPR-tasks was evaluated by both reliability (intra-class correlation coefficients (ICC’s)) and agreement (standard error of measurement (SEM)) measures.ResultsAge was not associated with increased JPR-errors for any of the contralateral or ipsilateral JPR-tasks. ICC’s ranged between 0.63 and 0.80 for contralateral JPR-tasks, and from 0.32 to 0.48 for ipsilateral tasks, except for one ipsilateral task where the reliability was similar to contralateral tasks (0.79). The SEM was comparable and small for all JPR-tasks, ranging between 1.1 and 2.1.ConclusionNo age-related decline in JPS of the asymptomatic shoulder was found, and good agreement between test and re-test measurements for all JPR-tasks as indicated by the small SEM. Show less
Geurkink, T.H.; Overbeek, C.L.; Marang-van de Mheen, P.J.; Nagels, J.; Nelissen, R.G.H.H.; Groot, J.H. de 2023
Purpose: This study aimed to quantify the extent to which age was associated with joint position sense (JPS) of the asymptomatic shoulder as measured by joint position reproduction (JPR) tasks and... Show morePurpose: This study aimed to quantify the extent to which age was associated with joint position sense (JPS) of the asymptomatic shoulder as measured by joint position reproduction (JPR) tasks and assess the reproducibility of these tasks.Methods: 120 Asymptomatic participants aged 18-70 years each performed 10 JPR-tasks. Both contralateral and ipsilateral JPR-tasks were evaluated on accuracy of JPR under active-and passive conditions at two levels within the shoulder forward flexion trajectory. Each task was performed three times. In a subgroup of 40 participants, the reproducibility of JPR-tasks was assessed one week after initial measurement. Reproducibility of JPR-tasks was evaluated by both reliability (intra-class correlation coefficients (ICC's)) and agreement (standard error of measurement (SEM)) measures. Results: Age was not associated with increased JPR-errors for any of the contralateral or ipsilateral JPR-tasks. ICC's ranged between 0.63 and 0.80 for contralateral JPR-tasks, and from 0.32 to 0.48 for ipsilateral tasks, except for one ipsilateral task where the reliability was similar to contralateral tasks (0.79). The SEM was comparable and small for all JPR-tasks, ranging between 1.1 and 2.1.onclusion: No age-related decline in JPS of the asymptomatic shoulder was found, and good agreement between test and re-test measurements for all JPR-tasks as indicated by the small SEM. Show less
Background: Scapular winging is a rare condition of the shoulder girdle that presents challenging treatment decisions for clinicians. To inform clinical practice, clinicians need guidance on what... Show moreBackground: Scapular winging is a rare condition of the shoulder girdle that presents challenging treatment decisions for clinicians. To inform clinical practice, clinicians need guidance on what the best treatment decision is for their patients, and such recommendations should be based on the total evidence available. Therefore, the purpose of this review was to systematically review the evidence regarding nonsurgical management and tendon transfer surgery of patients with neurologic scapular winging due to serratus anterior (SA) or trapezius (TP) palsy.Methods: PubMed, Embase, Web of Science, Cochrane Library, Emcare, and Academic Search Premier were searched up to April 5, 2022, for studies reporting on clinical outcomes after nonsurgical management and tendon transfer surgery of scapular winging due to weakness of the SA or TP muscle. The Integrated quality Criteria for Review Of Multiple Study (ICROMS) tool was used to classify the quality of the studies. Primary outcomes were the fraction of patients with spontaneous recovery after nonsurgical management and improvement in shoulder function, pain scores, and shoulder scores after tendon transfer surgery. Data were pooled if data on the same outcome were available for at least 3 studies, using random-effects meta-analysis.Results: Twenty-three (10 moderate-quality [MQ] and 13 low-quality) studies were included. Six studies (3 MQ; 234 shoulders) re-ported on outcomes after nonsurgical management of SA palsy, whereas 12 (6 MQ; 221 shoulders) and 6 studies (1 MQ; 80 shoulders) evaluated the outcomes of tendon transfer for SA or TP palsy (1 study addressed both). Spontaneous recovery of scapular winging with nonsurgical management varied between 21% and 78% across studies after a median follow-up of 72 months. For surgical management of SA palsy, pooling data in a meta-analysis showed that patients on average improved by 47 degrees (95% confidence interval [CI]: 34-61, P < .001) in active forward flexion, had lower visual analog scale scores for pain (mean difference [MD]: -3.0, 95% CI: -4.9 to -1.0, P = .003), and had substantial improvements in American Shoulder and Elbow Surgeons (MD: 24, 95% CI: 9-39, P = .002) and Constant Show less
Hoogervorst, L.A.; Schie, P. van; Nagels, J.; Nelissen, R.G.H.H.; Marang-van de Mheen, P.J. 2022
Background: To assess the extent of between-hospital variation in revision following primary shoulder arthroplasty (SA), both overall and for specific revision indications to guide quality... Show moreBackground: To assess the extent of between-hospital variation in revision following primary shoulder arthroplasty (SA), both overall and for specific revision indications to guide quality improvement initiatives, and to assess whether revision rates are suitable as quality indicators to reliably rank hospital performance. Methods: All primary SAs performed between 2014 and 2018 were included from the Dutch Arthroplasty Register to examine 1-year revision and all primary SAs performed between 2014 and 2016 for 1-and 3-year revisions. For each hospital, the observed number (O) of revisions was compared with that expected (E) based on case-mix and depicted in funnel plots with 95% control limits to identify outlier hospitals. The rankability (ie, the reliability of ranking hospitals) was calculated as the percentage of total hospital variation due to true between-hospital differences rather than chance and categorized as low (< 50%), moderate (50%-75%), and high (> 75%). Results: A total of 13,104 primary SAs (87 hospitals) in 2014-2018 were included, of which 7213 were performed between 2014 and 2016. Considerable between-hospital variation was found in 1-year revision in 2014-2016 (median 1.6%, interquartile range 0.0%-3.1%), identifying 3 outlier hospitals having overall significantly more revisions than expected (O/E range 1.9-2.3) and for specific in-dications (cuff pathology and infection). Results for 2014-2018 were similar. For 3-year revision, 3 outlier hospitals were identified (O/E range 1.7-3.3). Rankabilities for all outcomes were low. Conclusions: Considerable between-hospital variation was observed for 1-and 3-year revision rates following primary SA, where outlier hospitals could be identified based on large differences in revision for specific indications to direct quality improvement initiatives. However, rankabilities were low, meaning that much of the other (smaller) variation in performance could not be detected, rendering revisions unsuitable to rank hospital performances following primary SA.(C) 2022 The Author(s). Show less
Ulmann, E.T.E.; Malessy, M.J.A.; Nagels, J.; Pondaag, W. 2022
Background:A typical feature in infants with severe C5-C6 brachial plexus birth injury (BPBI) requiring nerve repair is the formation of shoulder internal rotation contracture (IRC). The underlying... Show moreBackground:A typical feature in infants with severe C5-C6 brachial plexus birth injury (BPBI) requiring nerve repair is the formation of shoulder internal rotation contracture (IRC). The underlying pathophysiological mechanism is unknown, and the sequelae can be difficult to treat. The severity of the IRC differs among children. C5-C6 lesions are heterogeneous at the root level. Our null hypothesis was that the type of root-level lesion (axonotmesis or neurotmesis versus avulsion) was not associated with the extent of IRC formation over time in children with upper-trunk BPBI.Methods:We performed a retrospective analysis of all patients with upper-trunk BPBI who underwent primary surgery of the C5 and/or C6 spinal nerves between 1990 and 2020 and had follow-up of at least 2 years. The primary outcome was passive shoulder external rotation (ER) in adduction at 1, 3, 5, 7, and 15 years of age. The secondary outcome was whether additional shoulder surgery was performed. The relationship between the nature of the C5-C6 lesion and IRC formation was analyzed using linear mixed models. The Kaplan-Meier method was used to estimate the cumulative risk of secondary shoulder procedures.Results:In total, 322 patients were analyzed; mean follow-up was 7.2 +/- 4.6 years. The C5-C6 root lesion type was significantly related to the passive range of ER (overall test in linear mixed model, p = 0.007). Children with avulsion of C5 and C6 (n = 21) had, on average, 18 degrees (95% confidence interval [CI], 6.3 degrees to 30 degrees) less IRC formation than those with neurotmesis of C5 and C6 (n = 175) and 17 degrees (2.9 degrees to 31 degrees) less than those with neurotmesis of C5 and avulsion of C6 (n = 34). IRC formation did not differ between the neurotmesis C5-C6 and neurotmesis C5-avulsion C6 groups. Secondary shoulder procedures were performed in 77 patients (10-year risk, 28% [95%CI, 23% to 34%]).Conclusions:Shoulder IRC formation in infants with BPBI with surgically treated C5-C6 lesions occurs to a lesser degree if the C5 root is avulsed than when C5 is neurotmetic. This finding provides insight into the possible causative pathoanatomy and may ultimately lead to strategies to mitigate IRC. Show less
Overbeek, C.; Kolk, A.; Witte, P.B. de; Nagels, J.; Nelissen, R.G.H.; Groot, J. de 2022
Background: Patients with Subacromial Pain Syndrome show reduced co-contraction of the teres major during abduction. Consequent insufficient humeral depressor function may contribute to painful... Show moreBackground: Patients with Subacromial Pain Syndrome show reduced co-contraction of the teres major during abduction. Consequent insufficient humeral depressor function may contribute to painful irritation of subacromial tissues and offers a potential target for therapy. A crucial gap in knowledge is whether the degree of teres major co-contraction in these patients is influenced by pain itself. To gain insight into this matter, we assessed whether relief of subacromial pain with local analgesics leads to increased adductor co-contraction in 34 patients with subacromial pain. Methods: In a single-arm interventional study with 34 patients, electromyographic activity of the latissimus dorsi, pectoralis major, teres major and deltoid was assessed during isometric force tasks in 24 directions before and after subacromial Lidocaine injection. Co-contraction was quantified using the activation ratio; range [-1 (sole antagonistic activation, i.e. co-contraction) to 1 (sole agonistic activation)]. Findings: There were no changes in activation ratio of the teres major after the intervention (Z-score:-0.6, p = 0.569). The activation ratio of the latissimus dorsi increased to 0.38 (quartiles: 0.13-0.76), indicating decreased co-contraction (Z-score: -2.0, p = 0.045). Interpretation: Subacromial analgesics led to a decrease in co-contraction of the latissimus dorsi, whereas no change in the degree of teres major co-contraction was observed. This study shows that decreased teres major co contraction in patients with subacromial pain, likely is not the consequence of pain itself, opening a window for physical therapy with training of teres major co-contraction to reduce subacromial irritation and pain. Level of evidence: Level II treatment study. Show less
Kolk, A.; Overbeek, C.L.; Witte, P.B. de; Canete, A.N.; Reijnierse, M.; Nagels, J.; ... ; Groot, J.H. de 2021
Background: Conflicting theories exist about the underlying cause of chronic subacromial pain in the middle-aged population. We aim to improve our understanding of kinematics and muscle activation... Show moreBackground: Conflicting theories exist about the underlying cause of chronic subacromial pain in the middle-aged population. We aim to improve our understanding of kinematics and muscle activation in subacromial pain syndrome to provide insight in its pathophysiology. Methods: In a cross-sectional comparison of 40 patients with subacromial pain syndrome and 30 asymptomatic controls, three-dimensional shoulder kinematics and electromyography-based co-contraction in 10 shoulder muscles were independently recorded. Glenohumeral and scapulothoracic kinematics were evaluated during abduction and forward flexion. Co-contraction was expressed as an activation ratio, specifying the relative agonistic and antagonistic muscle activity in each muscle. Findings: During abduction and forward flexion, the contribution of glenohumeral motion to elevation and glenohumeral external rotation was lower in subacromial pain syndrome (at 1200 abduction: - 9 degrees, 95% CI -14 degrees- -3 degrees; and - 8 degrees, 95% CI -13 degrees -3 degrees, respectively), and was compensated by more scapulothoracic motion. The pectoralis major's activation ratio was significantly lower (Z-score: -2.657, P = 0.008) and teres major's activation ratio significantly higher (Z-score: -4.088, P < 0.001) in patients with subacromial pain syndrome compared to the control group. Interpretation: Reduced glenohumeral elevation and external rotation in subacromial pain syndrome coincided with less teres major antagonistic activity during elevation. These biomechanical findings provide a scientific basis for intervention studies directed at stretching exercises to reduce glenohumeral stiffness in the treatment of subacromial pain syndrome, and teres major strengthening to improve humeral head depressor function. Show less
Overbeek, C.L.; Gademan, M.G.J.; Kolk, A.; Visser, C.P.J.; Zwaal, P. van der; Nagels, J.; Nelissen, R.G.H.H. 2021
Background: Patients with subacromial pain syndrome (SAPS) frequently present with coexisting psychosocial problems; however, whether this also associates with long-term outcome is currently... Show moreBackground: Patients with subacromial pain syndrome (SAPS) frequently present with coexisting psychosocial problems; however, whether this also associates with long-term outcome is currently unknown. We assessed whether psychosocial functioning in patients with SAPS is associated with persistence of complaints after 4 years of routine care.Methods: In a longitudinal study, 34 patients with SAPS were selected after clinical and radiologic evaluation and assessed at baseline and after 4 years. For the assessment of psychosocial functioning, the RAND-36 questionnaire domains of social functioning, role limitations due to emotional problems, mental health, vitality, and general health were evaluated. Complaint persistence at follow-up was assessed by (1) an anchor question (reduced, persistent, or increased symptoms), (2) change in pain (change in visual analog scale score), and (3) change in quality of life (change in Western Ontario Rotator Cuff index score).Results: Lower baseline mental health (odds ratio [OR], 0.92; 95% confidence interval [CI], 0.85-0.98; P = .013), vitality (OR, 0.90; 95% CI, 0.83-0.98; P = .011), and general health (OR, 0.93; 95% CI, 0.88-0.98; P = .009) were associated with persistent complaints as reported by the anchor question, change in visual analog scale score, and change in Western Ontario Rotator Cuff index score.Conclusions: Evaluating psychosocial functioning parallel to physical complaints is currently not standard procedure in the treatment of SAPS. In this study, we showed that factors related to psychosocial functioning are associated with long-term persistence of complaints in SAPS. Future studies may investigate whether a multimodal treatment with assessment of psychosocial functioning may facilitate pain relief and recovery in SAPS. (c) 2020 The Author(s). This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Show less
Healthy individuals perform a task such as hitting the head of a nail with an infinite coordination spectrum. This motor redundancy is healthy and allows for learning through exploration and... Show moreHealthy individuals perform a task such as hitting the head of a nail with an infinite coordination spectrum. This motor redundancy is healthy and allows for learning through exploration and uniform load distribution across muscles. Assessing movement complexity within repetitive movement trajectories may provide insight into the available motor redundancy during aging. We quantified complexity of repetitive arm elevation trajectories in the aging shoulder and assessed test-retest reliability of this quantification. In a cross-sectional study using 3D-electromagnetic tracking, 120 asymptomatic subjects, aged between 18 and 70 years performed repetitive abduction and forward/anteflexion movements. Movement complexity was calculated using the Approximate Entropy (ApEn-value): [0,2], where lower values indicate reduced complexity. Thirty-three participants performed the protocol twice, to determine reliability (intraclass correlation coefficient [ICC]). The association between age and ApEn was corrected for task characteristics (e.g., sample length) with multiple linear regression analysis. Reproducibility was determined using scatter plots and ICC's. Higher age was associated with lower ApEn-values during abduction (unstandardized estimate: -0.003/year; 95% confidence interval: [-0.005; -0.002]; p < .001). ICC's revealed poor to good reliability depending on differences in sample length between repeated measurements. The results may imply more stereotype movement during abduction in the ageing shoulder, making this movement prone to the development of shoulder complaints. Future studies may investigate the pathophysiology and clinical course of shoulder complaints by assessment of movement complexity. To this end, the ApEn-value calculated over repetitive movement trajectories may be used, although biasing factors such as sample length should be taken into account. Show less
Background: Generating a force at the hand requires moments about multiple joints by a theoretically infinite number of arm and shoulder muscle force combinations. This allows for learning and... Show moreBackground: Generating a force at the hand requires moments about multiple joints by a theoretically infinite number of arm and shoulder muscle force combinations. This allows for learning and adaptation and can possibly be captured using the complexity (entropy) of an isometrically generated force curve. Patients with Subacromial Pain Syndrome have difficulty to explore alternative, pain-avoiding, motor strategies and we questioned whether loss of motor complexity may contribute to this. We assessed whether patients with Subacromial Pain Syndrome have reduced entropy of an isometrically generated abduction and adduction force curve.Methods: Forty patients and thirty controls generated submaximal isometric ab- and adduction force at the wrist. The force curve was characterized by the magnitude of force variability [standard deviation and coefficient of variation], and the entropy (complexity) of force variability [approximate entropy].Findings: Patients showed reduced entropy both during the abduction (-0.16, confidence interval: [-0.33; 0.00], p: 0.048) and adduction task (-0.20, confidence interval: [-0.37; 0.03], p: 0.024) and reduced force variability during abduction (standard deviation: 0.006, confidence interval: [-0.011; -0.001], p: 0.013 and coefficient of variation: -0.51, confidence interval: [-0.93; -0.10], p: 0.016).Interpretations: Isometric force curves of patients with Subacromial Pain Syndrome show reduced complexity compared to asymptomatic controls, which may indicate more narrow and stereotype use of motor options. In future studies, it should be investigated whether the finding of reduced force (motor) entropy indicates functional decline, contributing to decreased ability to acquire and optimize motor strategies in Subacromial Pain Syndrome. Show less
Background:Physical exercises targeting proprioception are part of conservative therapy for Subacromial Pain Syndrome (SAPS). However, the effect of such exercises on proprioception itself has not... Show moreBackground:Physical exercises targeting proprioception are part of conservative therapy for Subacromial Pain Syndrome (SAPS). However, the effect of such exercises on proprioception itself has not been orderly established, hampering the advancement of treatment protocols and implementation. We summarised the evidence for a loss of proprioception in SAPS and defined the type of interventions that target and improve proprioception in SAPS. Methods:Two reviewers independently analysed 12/761 articles that evaluated joint position, kinaesthetic or force sense in patients with SAPS. Results:Patients with SAPS had reduced joint position sense during abduction. There was no evidence for a loss of kinaesthetic sense or force sense. Stretching, strengthening and stabilisation exercises improved joint position and kinaesthetic sense in SAPS. Microcurrent electrical stimulation and kinesiotaping did not improve proprioception in SAPS. Conclusions:The lack of evidence on proprioception in SAPS is striking. We found limited evidence for a loss of joint position sense in the higher ranges of abduction in SAPS. Active training programmes including strengthening and stabilisation exercises showed superiority in terms of enhancing proprioception relative to passive methods like kinesiotaping. The results of this narrative synthesis should be used as a base for providing value-based and data-driven treatment solutions to SAPS. Show less
Background Obstetric brachial plexus injuries result from traction injuries during delivery, and 30% of these children have persisting functional limitations related to an external rotation deficit... Show moreBackground Obstetric brachial plexus injuries result from traction injuries during delivery, and 30% of these children have persisting functional limitations related to an external rotation deficit of the shoulder. Little is known about the long-term effect of soft-tissue procedures of the shoulder in patients with obstetric brachial plexus injuries. Questions/purposes (1) After soft-tissue release for patients with passive external rotation less than 20 degrees and age younger than 2 years and for patients older than 2 years with good external rotation strength, what are the improvements in passive external rotation and abduction arcs at 1 and 5 years? (2) For patients who underwent staged tendon transfer after soft-tissue release, what are the improvements in active external rotation and abduction arcs at 1 and 5 years? (3) For patients with passive external rotation less than 20 degrees and no active external rotation, what are the improvements in active external rotation and abduction arcs at 1 and 5 years? Methods This was a retrospective analysis of a longitudinally maintained institutional database. Between 1996 and 2009, 149 children underwent a soft-tissue procedure of the shoulder for an internal rotation contracture. The inclusion criteria were treatment with an internal contracture release and/or tendon transfer, a maximum age of 18 years at the time of surgery, and a minimum follow-up period of 2 years. Six patients were older than 18 years at the time of surgery and 31 children were seen at our clinic until 1 year postoperatively, but because they had good clinical results and lived far away from our center, these children were discharged to physical therapists in their hometown for annual follow-up. Thus, 112 children (59 boys) were available for analysis. Patients with passive external rotation less than 20 degrees and age younger than 2 years and patients older than 2 years with good external rotation strength received soft-tissue release only (n = 37). Of these patients, 17 children did not have adequate active external rotation, and second-stage tendon transfer surgery was performed. For patients with passive external rotation less than 20 degrees with no active external rotation, single-stage contracture release with tendon transfer was performed (n = 68). When no contracture was present (greater than 20 degrees of external rotation) but the patient had an active deficit (n = 7), tendon transfer alone was performed; this group was not analyzed. A functional assessment of the shoulder was performed preoperatively and postoperatively at 6 weeks, 3 months, and annually thereafter and included abduction, external rotation in adduction and abduction, and the Mallet scale. Results Internal contracture release resulted in an improvement in passive external rotation in adduction and abduction of 29 degrees (95% confidence interval, 21 to 38; p < 0.001) and 17 degrees (95% CI, 10 to 24; p < 0.001) at 1 year of follow-up and 25 degrees (95% CI, 15-35; p < 0.001) and 15 degrees (95% CI, 7 to 24; p = 0.001) at 5 years. Because of insufficient strength of the external rotators after release, 46% of the children (17 of 37) underwent an additional tendon transfer for active external rotation, resulting in an improvement in active external rotation in adduction and abduction at each successive follow-up visit. Patients with staged transfers had improved active function; improvements in active external rotation in adduction and abduction were 49 degrees (95% CI, 28 to 69; p < 0.05) and 45 degrees (95% CI, 11 to 79; p < 0.001) at 1 year of follow-up and 38 degrees (95% CI, 19 to 58; p < 0.05) and 23 degrees (95% CI, -8 to 55; p < 0.001) at 5 years. In patients starting with less than 20 degrees of passive external rotation and no active external rotation, after single-stage contracture release and tendon transfer, active ROM was improved. Active external rotation in adduction and abduction were 75 degrees (95% CI, 66 to 84; p < 0.001) and 50 degrees (95% CI, 43 to 57; p < 0.001) at 1 year of follow-up and 65 degrees (95% CI, 50 to 79; p < 0.001) and 40 degrees (95% CI, 28 to 52; p < 0.001) at 5 years. Conclusion Young children with obstetric brachial plexus injuries who have internal rotation contractures may benefit from soft-tissue release. When active external rotation is lacking, soft-tissue release combined with tendon transfer improved active external rotation in this small series. Future studies on the degree of glenohumeral deformities and functional outcome might give more insight into the level of increase in external rotation. Show less
Overbeek, C.L.; Kolk, A.; Groot, J.H. de; Witte, P.B. de; Gademan, M.G.J.; Nelissen, R.G.H.H.; Nagels, J. 2019
Middle-aged individuals cocontract with adductor muscles during abduction. This may be crucial for counteracting deltoid forces, depressing the humerus and ensuring free passage of subacromial... Show moreMiddle-aged individuals cocontract with adductor muscles during abduction. This may be crucial for counteracting deltoid forces, depressing the humerus and ensuring free passage of subacromial tissues underneath the acromion during abduction. We questioned whether adductor co-contraction is always present, or develops during ageing, in which case it may explain the age-related character of common shoulder conditions such as Subacromial Pain Syndrome. In a cross-sectional analysis with electromyography (EMG), activation patterns of the latissimus dorsi, teres major, pectoralis major and deltoid muscle were assessed during isometric force tasks in 60 asymptomatic individuals between 21 and 60 years old. Cocontraction was expressed as the degree of antagonistic activation relative to the same muscle's degree of agonistic activation, resulting in an activation ratio between -1 and 1, where lower values indicate more cocontraction. Using linear regression analyses, we found age-related decreases in the activation ratio of the latissimus dorsi (regression estimate: -0.004, 95% CI: -0.007 to 0.0, p-value: 0.042) and teres major (regression estimate: -0.013, 95% CI: -0.019 to -0.008, p-value: < 0.001). In contrast to young individuals, middle-aged individuals showed a high degree of adductor cocontraction during abduction. This may indicate that during ageing, alterations in activation patterns are required for preserving pain-free shoulder function. Show less
Overbeek, C.L.; Kolk, A.; Groot, J.H. de; Visser, C.P.J.; Zwaal, P. van der; Jens, A.; ... ; Nelissen, R.G.H.H. 2019
Background In approximately 29% to 34% of all patients with subacromial pain syndrome (SAPS) there is no anatomic explanation for symptoms, and behavioral aspects and/or central pain mechanisms may... Show moreBackground In approximately 29% to 34% of all patients with subacromial pain syndrome (SAPS) there is no anatomic explanation for symptoms, and behavioral aspects and/or central pain mechanisms may play a more important role than previously assumed. A possible behavioral explanation for pain in patients with SAPS is insufficient active depression of the humerus during abduction by the adductor muscles. Although the adductor muscles, specifically the teres major, have the most important contribution to depression of the humerus during abduction, these muscles have not been well studied in patients with SAPS.Questions/purposes Do patients with SAPS have altered contraction patterns of the arm adductors during abduction compared with asymptomatic people?Methods SAPS was defined as nonspecific shoulder pain lasting for longer than 3 months that could not be explained by specific conditions such as calcific tendinitis, full-thickness rotator cuff tears, or symptomatic acromioclavicular arthritis, as assessed with clinical examination, radiographs, and magnetic resonance arthrography. Of 85 patients with SAPS who met the prespecified inclusion criteria, 40 were eligible and agreed to participate in this study. Thirty asymptomatic spouses of patients with musculoskeletal complaints, aged 35 to 60 years, were included; the SAPS and control groups were not different with respect to age, sex, and hand dominance. With electromyography, we assessed the contraction patterns of selected muscles that directly act on the position of the humerus relative to the scapula (the latissimus dorsi, teres major, pectoralis major, and deltoid muscles). Cocontraction was quantified through the activation ratio ([AR]; range, -1 to 1). The AR indicates the task-related degree of antagonist activation relative to the same muscle's degree of agonist activation, equaling 1 in case of sole agonist muscle activation and equaling -1 in case of sole antagonistic activation (cocontraction). We compared the AR between patients with SAPS and asymptomatic controls using linear mixed-model analyses. An effect size of 0.10 < AR < 0.20 was subjectively considered to be a modest effect size.Results Patients with SAPS had a 0.11 higher AR of the teres major (95% CI, 0.01-0.21; p = 0.038), a 0.11 lower AR of the pectoralis major (95% CI, -0.18 to -0.04; p = 0.003), and a 0.12 lower AR of the deltoid muscle (95% CI, -0.17 to -0.06; p < 0.001) than control participants did. These differences were considered to be modest. With the numbers available, we found no difference in the AR of the latissimus dorsi between patients with SAPS and controls (difference = 0.05; 95% CI, -0.01 to 0.12; p = 0.120).Conclusions Patients with SAPS showed an altered adductor cocontraction pattern with reduced teres major activation during abduction. The consequent reduction of caudally directed forces on the humerus may lead to repetitive overloading of the subacromial tissues and perpetuate symptoms in patients with SAPS. Physical therapy programs are frequently effective in patients with SAPS, but targeted approaches are lacking. Clinicians and scientists may use the findings of this study to assess if actively training adductor cocontraction in patients with SAPS to unload the subacromial tissues is clinically effective. The efficacy of training protocols may be enhanced by using electromyography monitoring. Show less
Overbeek, C.L.; Kolk, A.; Nagels, J.; Witte, P.B. de; Zwaal, P. van der; Visser, C.P.J.; ... ; Groot, J.H. de 2019
