The effects of scapular taping on electromyographic muscle activity and proprioception feedback in healthy shoulders

We investigated the effects of scapular tape on the electromyographic (EMG) activity of the upper trapezius (UT), lower trapezius (LT), serratus anterior (SA), anterior deltoid (AD), and shoulder proprioception in 12 healthy shoulders. Participants were blindfolded and required to complete a target end/mid range position with the hand. They performed six trials under two experimental conditions; no tape and therapeutic tape. EMG activity was measured by surface electrodes, and proprioception was measured by the FASTRAK electromagnetic motion tracking system. Two‐way repeated measures ANOVA showed that UT and AD activities decreased 2.65% (p = 0.001), and SA muscular activities increased 1.9% (p = 0.015) in the taping condition. The proprioceptive feedback magnitude was significantly lower in the taping condition than in the no taping condition (11.9°, p < 0.005). Additionally, correlation coefficients were higher than 0.5 between muscle activity and proprioceptive feedback with the taping condition; UT and magnitude in the mid range task (R = 0.516); LT and magnitude in the end range task (R = ?0.524); and SA and magnitude in the mid range task (R = ?0.576). The results suggest that scapular tape affects the muscle activity of UT, AD, and SA, and that the effects are related to proprioception feedback. These results implicate that the mechanisms by which scapular taping induces effects can be explained by neuromuscular control and proprioceptive feedback factors. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29:53–57, 2011     

Adaptive patterns of movement during arm elevation test in patients with shoulder impingement syndrome

The purpose of this study was to determine if a distinctive characteristic exists in the pattern of movement (scapular elevation and upward rotation to reduce impingement) and associated muscular activities during arm elevation in subjects with shoulder impingement (SI) that is associated with the severity of the disease. Fourteen subjects (7 amateur athletes and 7 student athletes) with SI and 7 controls performed arm elevation in the scapular plane. Scapular kinematics (upward rotation, elevation, tipping, and scapulohumeral rhythm) and muscular activity [upper trapezius (UT), lower trapezius (LT), serratus anterior (SA), and deltoid] were measured by an electromagnetic motion tracking system and surface electromyography, respectively. Subjects with SI had greater elevation of the scapula (11.9 mm, p < 0.005) and less peak scapular posterior tipping (10.6°, p < 0.02) than controls. In more severe subjects (amateur athletes), the elevation and posterior tipping of the scapula were correlated with an increase in the UT (R = ?0.818, p = 0.025) and a decrease in SA (R = 0.772, p = 0.040) activity, respectively. Our results identified a characteristic compensatory scapular elevation to reduce impingement during arm elevation in subjects with SI. Assessing scapular elevation during arm elevation may be a useful functional marker for evaluating impingement status and associated muscle function. Additionally, SA and LT muscle strengthening may improve SI. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29:653–657, 2011     

A three-dimensional scapular motion analysis in patients with arthroscopic anterior capsulolabral repair of the shoulder: The effect of scapular stabilization taping

BackgroundThe aim of this study was to investigate the scapular kinematics during dynamic humeral movements in patients with arthroscopic anterior capsulolabral repair of the shoulder along with the potential biomechanical corrective effects of scapular stabilization taping.MethodsTwenty patients with unilateral traumatic anterior shoulder instability and arthroscopic anterior capsulolabral repair participated in the study. Dynamic shoulder kinematics were assessed during the scapular plane shoulder elevation for both the operated and non operated shoulders and also under two conditions: no-taping and taping. Statistical analysis to compare sides and conditions was performed with analysis of variance models.ResultsThe scapula was more internally rotated position in operated shoulders than in non operated shoulders. Furthermore, the scapula was less internally rotated and more downwardly rotated at 120° of elevation in the taping condition.ConclusionsOperated shoulders demonstrated kinematics alterations when compared to non operated shoulders underwent arthroscopic anterior capsulolabral repair. Additionally, changes in the scapular orientation with the taping was very small but followed a pattern, which would be suggested to be an orientation that potentially produce more scapular stability and to increase stress on the inferior glenohumeral ligament.     

Does scapular corrective taping alter periscapular muscle activity and 3-dimensional scapular kinematics? A systematic review

Study DesignThis is a systematic review.IntroductionScapular taping is widely used in the management of scapular dysfunction. However, its effects on the scapular kinematics and the electromyography (EMG) activity of the periscapular muscles are not clear.Purpose of the StudyThe purpose of the study was to systematically review the current literature to examine whether scapular corrective taping alters the EMG activity of the periscapular muscles and the 3-dimensional scapular kinematics.MethodMEDLINE and Web of Science databases were searched using specific mesh terms up to April 2018. A hand search was also conducted on the reference list of the included articles. A total of 157 studies were identified, and they were further analyzed for the eligibility to the systematic review. Studies that investigated the effects of scapular corrective taping on the EMG activity of the periscapular muscles and on the 3-dimensional scapular kinematics on patients with shoulder problems or asymptomatic subjects were eligible for the systematic review. The Cochrane Effective Practice and Organization of Care criteria were modified and used for the risk-of-bias assessment.ResultsEleven articles met the inclusion criteria and were included in the systematic review. Five studies investigated the effects of corrective taping on the scapular kinematics and 8 studies reported the effects of corrective taping on the EMG activity of the periscapular muscles. There was an agreement among the studies that scapular upward rotation is increased with the corrective taping, while there are inconsistent results concerning the scapular external rotation and posterior tilt. In addition, studies mostly reported that corrective taping decreases the activity of the upper trapezius, while it has conflicting effects on the activity patterns of other periscapular muscles.DiscussionScapular corrective taping was found to increase the scapular upward rotation; however, its effects on scapular external rotation and posterior tilt are controversial. It was also found that corrective taping might decrease the EMG activity of the upper trapezius, while it had no effects on the activity of lower trapezius, and its effects on other periscapular muscles were controversial.ConclusionThe results of the studies indicated that scapular corrective taping might alter the 3-dimensional scapular kinematics, while there are controversies about the effects of corrective taping on the EMG activity of the periscapular muscles. Further studies are needed to clarify the conflicts.     

The effects of scapular taping on the surface electromyographic signal amplitude of shoulder girdle muscles during upper extremity elevation in individuals with suspected shoulder impingement syndrome

STUDY DESIGN: Multifactorial, repeated-measures, within-subjects design. OBJECTIVES: To investigate the immediate effects of scapular taping on surface electromyographic (EMG) signal amplitude of shoulder girdle muscles during upper extremity elevation in individuals with suspected shoulder impingement syndrome. BACKGROUND: Individuals with shoulder impingement syndrome may present with increased activity of the upper trapezius and inhibition of other shoulder muscles active during upper extremity elevation. Scapular taping is theorized to normalize shoulder girdle function during scapular upward rotation by decreasing upper trapezius activity and increasing the activity of the lower trapezius and other muscles. assessed for each muscle. RESULTS: Upper trapezius activity was significantly lower with tape during shelf task elevation (P = .002), especially above 90 degrees (P<.002). Lower trapezius activity was significantly higher with tape (P = .043). No significant differences were found between the tape and no tape for other muscles for the shelf task. During shoulder abduction in the scapular plane, the main effect for upper trapezius showed a significant decrease of EMG signal amplitude (P = .047) for tape versus no tape, but no significant interactions were found among components of this activity, or for other muscles. CONCLUSION: Scapular taping decreased upper trapezius and increased lower trapezius activity in people with suspected shoulder impingement during a functional overhead-reaching task, and decreased upper trapezius activity during shoulder abduction in the scapular plane. Taping did not affect the other muscles under the loads tested, but it is possible that the activity of these muscles was not deficient at the time of testing.     

Scapular muscles strengthening on pain,functional outcome and muscle activity in chronic lateral epicondylalgia

Aim

The aim of the study was to investigate the effect of lower trapezius (LT), middle trapezius (MT) and serratus anterior (SA) strengthening on pain, pain free grip strength, functional outcome, scapular muscles strength, scapular position and electromyographic (EMG) activity of lower trapezius, serratus anterior, extensor carpi radialis brevis (ECRB) and extensor digitorum communis (EDC) in individuals with chronic lateral epicondylalgia (LE).

Efficacy of 3 therapeutic taping configurations for children with brachial plexus birth palsy

Study Design

Cross-sectional clinical measurement study.

Supraspinatus and infraspinatus weakness in overhead athletes with scapular dyskinesis: strength assessment before and after restoration of scapular musculature balance

A disturbance in scapulohumeral rhythm may cause negative biomechanic effects on rotator cuff (RC). Alteration in scapular motion and shoulder pain can influence RC strength. Purpose of this study was to assess supraspinatus and infraspinatus strength in 29 overhead athletes with scapular dyskinesis, before and after 3 and 6 months of rehabilitation aimed to restore scapular musculature balance. A passive posterior soft tissues stretching was prescribed to balance shoulder mobility. Scapular dyskinesis patterns were evaluated according to Kibler et al. Clinical assessment was performed with the empty can (EC) test and infraspinatus strength test (IST). Strength values were recorded by a dynamometer; scores for pain were assessed with VAS scale. Changes of shoulder IR were measured. The force values increased at 3 months (P < 0.01) and at 6 months (P < 0.01). Changes of glenohumeral IR and decrease in pain scores were found at both follow-up. Outcomes registered on pain and strength confirm the role of a proper scapular position for an optimal length–tension relationship of the RC muscles. These data should encourage those caring for athletes to consider restoring of scapular musculature balance as essential part of the athletic training.     

The effect of long versus short pectoralis minor resting length on scapular kinematics in healthy individuals

STUDY DESIGN: Two-group comparison. OBJECTIVE: To compare scapular kinematics during arm elevation between groups distinguished by pectoralis minor resting length. BACKGROUND: Studies have demonstrated that individuals with subacromial impingement have altered scapular kinematics, such as loss of posterior tipping and increased internal rotation. One proposed mechanism for these alterations is an adaptively short pectoralis minor. This anterior scapulothoracic muscle may impact normal scapular kinematics if adaptively short. METHODS AND MEASURES: Fifty volunteers without shoulder pain were divided into long or short groups according to normalized pectoralis minor resting length. An electromagnetic motion capture system determined the angular orientation of the scapula, humerus, and trunk during arm elevation in 3 separate planes. Groups were compared for 3-dimensional scapular orientation relative to the trunk at arm elevation angles of 30 degrees, 60 degrees, 90 degrees, and 120 degrees, using a mixed-model analysis of variance (ANOVA). RESULTS: There were statistically significant interaction effects between group and arm elevation angle for scapular tipping in all planes of arm elevation, with the scapula for the short group staying anteriorly tipped at higher angles. There was also a significant interaction for scapular internal rotation at lower arm elevation angles in the coronal plane only, with individuals with a shorter pectoralis minor demonstrating a more internally rotated scapula. CONCLUSIONS: The group distinguished by a short pectoralis minor demonstrated scapular kinematics similar to the kinematics exhibited in earlier studies by subjects with shoulder impingement. These results support the theory that an adaptively short pectoralis minor may influence scapular kinematics and is therefore a potential mechanism for subacromial impingement.     

Effect of Kinesio taping on wrist kinematics and functional performance: A randomized controlled trial

BackgroundKinesio taping (KT) is a popular adjunct treatment modality for musculoskeletal injuries, hand and wrist injuries. The effectiveness of KT on wrist kinematics has been analyzed during single plane movements in general, and no study has investigated its effectiveness during dart throwing motion (DTM).PurposeTo compare the effects of different KT techniques on wrist kinematics during DTM and functional performance of hand in healthy participants.Study DesignRandomized, double-blind, placebo-controlled, crossover study.MethodsSeventy-two healthy participants were included. Dominant wrist kinematics during DTM was evaluated by a Leap motion controller and wrist functional performance was evaluated by Minnesota Manual Dexterity Test. In order to compare the effects of KT on different muscles and also the effects of KT and placebo taping (PT), wrists of participants were evaluated under 5 conditions: without any taping, KT on flexor carpi ulnaris (FCU), KT on extensor carpi radialis brevis and longus (ECRB/L), PT on FCU and PT on ECRB/L. Means of outcome measures without any taping and with different 4 tapings were compared by repeated measures analysis of variance. PT and KT effects were compared by Wilcoxon signed rank test.ResultsDTM range increased (P = .0) and Minnesota Manual Dexterity Test time decreased (P = .0) after KT and PT applications on FCU and ECRB/L muscles. Amount of change in wrist kinematics (P = .0; effect size = 0.2 and 0.3) and functional performance (P = .0; effect size = 0.6 and 0.8) were more obvious with KT applications, independent from the muscles they were applied on (P = .2 for wrist kinematics and P = .7 for functional performance).ConclusionsKT on either FCU or ECRB/L muscles improve wrist kinematics and functional performance, significantly. Further studies should investigate if these findings apply for the patients with different wrist injuries, for both immediate- and long-term effectiveness.     

Effective rehabilitation in patients with scapular dyskinesis

For a balanced scapulohumeral rhythm in arm elevation, it is necessary to have an optimal position, motion, stability and muscle performance of the scapula and scapular muscles. In the case of abnormal movements, so-called scapular dyskinesis, the tendons (e.g. biceps tendon, rotator cuff) can be irritated and may cause pain in overhead activity. There are various causes for scapular dyskinesis and, therefore, the treatment is a challenge for therapists. The aim of conservative treatment is to restore normal position and movement of the scapula and furthermore dynamic scapular stability during overhead activities. Rehabilitation based on effective exercises should be tailored individually and the complexity of the exercises should be increased slowly.     

Four‐week exercise program does not change rotator cuff muscle activation and scapular kinematics in healthy subjects

Rotator cuff and scapular muscle strengthening exercises are an essential part of shoulder rehabilitation and sports training. Although the effect of exercise training on pain and function have been widely investigated, few studies have focused on the changes in shoulder kinematics and muscle activity after exercise training. Therefore, the purpose of the present study was to investigate the effect of rotator cuff and scapular strengthening exercises on shoulder kinematics and the activation of rotator cuff and scapular muscles in healthy subjects. Thirty‐six healthy subjects were recruited and randomly assigned into either a training or control group. Subjects in the training group were trained with rotator cuff and scapular strengthening exercises for 4 weeks. Scapular kinematics and shoulder muscle activity during arm elevation were measured before and after exercise training. After the 4‐week training protocol, there was an increase in strength and a decrease in upper trapezius activation in the training group, which is consistent with previous studies. However, no difference was found in scapular kinematics and activation of rotator cuff muscles between the control and training groups after the training protocol. Although the exercise protocol resulted in strength gains for the rotator cuff, these gains did not transfer to an increase in muscle activation during motion. These results demonstrate the difficulty in changing activation patterns of the rotator cuff muscles. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:2079–2088, 2016.     

Alterations in scapular kinematics in subjects with idiopathic loss of shoulder range of motion

STUDY DESIGN: Prospective cohort study. OBJECTIVE: To determine the effect of idiopathic loss of shoulder range of motion on scapular kinematics. BACKGROUND: Subjects with idiopathic loss of shoulder range of motion have difficulty performing activities of daily living. Previous investigations have focused on the glenohumeral component of shoulder complex motion. MATERIALS AND METHODS: Seventeen unilaterally impaired and 17 nonimpaired subjects. The 3-dimensional motion of the humerus, scapula, and trunk were measured withthe Fastrak electromagnetic motion-tracking system during humerus-to-trunk scapular plane elevation. An analysis of variance compared the impaired subjects noninvolved to the nonimpaired subjects' scapulae at 4 scapularplane elevation positions. A repeated-measures analysis of variance compared the impaired subjects' involved and noninvolved scapulae at 3 scapular plane elevation positions, and matched-pairs t test compared peak elevation values. RESULTS: The between-group ANOVAs demonstrated no difference in anterior tipping, internal rotation, or upward rotation. The repeated-measures ANOVAs demonstrated no difference in anterior tipping or internal rotation and a position-by-side interaction in upward rotation. The involved-side scapulae were more upwardly rotated (7.7 degrees) at peak humerus-to-trunk scapular plane elevation. DISCUSSION AND CONCLUSION: The impaired subjects' noninvolved scapular kinematics were not significantly different than the nonimpaired subjects, but were significantly different than their involved scapulae. The upward rotation differences may be a substitution pattern used to accomplish functional elevation.     

Risk of Hepatic Artery Complications After Liver Transplantation in Patients Who Received Pretransplant Transarterial Chemoembolization Therapy: A Single-Center Experience

BackgroundPretransplant transarterial chemoembolization (TACE) for patients with hepatocellular carcinoma (HCC) has been associated with an increased risk of hepatic artery thrombosis (HAT) after liver transplantation (LT). Innovative surgical LT and interventional vascular radiology TACE techniques may mitigate the risk of HAT. We sought to investigate the incidence of HAT after LT in patients who received pre-transplant TACE at our center.MethodsWe performed a single-center retrospective review of all LT patients, >18 years of age, from October 1, 2012, to May 31, 2018. Outcomes were compared between patients who received pre-LT TACE and those who did not. Median follow-up was 26 months.ResultsAmong the 162 LT recipients, 110 (67%) patients did not receive pre-LT TACE (Group I), while 52 (32%) received pre-LT TACE (Group II). The <30-day incidence rates of post-LT HAT were as follows: Group I = 1.8% and Group II = 1.9% (P = .9). Most hepatic arterial complications occurred >30 days after LT. Based on competing risks regression analysis, TACE was not associated with an increased risk of HAT. Patient or graft survivals were comparable between the 2 groups (P = .1 and .2, respectively).ConclusionsOur study shows a similar incidence of hepatic artery complications post-LT in patients who received TACE before LT compared with those who did not. In addition, we suggest that the surgical technique of early vascular control of the common hepatic artery during LT, in combination with a super-selective vascular intervention radiology approach, has clinical utility in reducing the risk of HAT in patients requiring pre-transplant TACE.     

Statistical shape modeling-based reconstruction eliminates the need for full scapular computed tomography scan data in preoperative total shoulder arthroplasty planning

BackgroundPreoperative total shoulder arthroplasty (TSA) planning tools use a three-dimensional (3D) model of the full scapula based on computed tomography (CT) images with a scan length covering the complete scapula with a given radiation exposure for patients. The aim of this study is to investigate whether full scapular models can be reconstructed from partial CT data.MethodsIn this retrospective cohort study, bone models representing 5 scan lengths with decreasing levels of scapular coverage (level 1-5) were created. All the models were reconstructed with a validated statistical shape model (SSM) allowing automatic 3D measurements of glenoid version, inclination, scapular offset, and center point position. Radiation exposure between 2 patient groups (group 1 = corresponding to L1, group 2 = complete scapula) was compared.ResultsIn terms of inclination and version, we found a mean absolute difference between the complete model and the different partial scan models of 0.5° (SD 0.4°). The maximum difference was 3° for inclination and 2° for version. For scapular offset and center point position, the mean difference was 0 mm (max 1 mm). The mean radiation exposure was 4 mSv (SD 2 mSv) for group 1 and 13 mSv (SD 6 mSv) for group 2 (P = .009).ConclusionAn SSM-based reconstruction technique can accurately reconstruct complete scapular bone models based on partial CT scan data. Incorporation of an SSM-based reconstruction technique in software tools for preoperative TSA planning would lead to decreased radiation exposure (9 mSv) for patients without influencing its accuracy.     

The influence of three-dimensional scapular kinematics on arm elevation angle in healthy subjects

BackgroundWe often clinically observe individual differences in arm elevation angles, but the motion producing these differences remains unclear, partly because of the difficulty of accurately measuring scapular motion. The aim of this study was to determine whether the scapular or glenohumeral (GH) motion has more influence on differences in the arm elevation angles by capturing not only the humerus and scapula but also the trunk using two- (2D) and three-dimensional (3D) shape-matching registration techniques.MethodsFifteen healthy subjects (13 male and 2 female; mean age: 27.7 years) were instructed to elevate their arms in the sagittal, scapular, and coronal planes. They were divided into high and low groups based on the average of arm elevation angle measured by a goniometer. The 3D scapular, thoracohumeral, and glenohumeral motions were evaluated using 2D/3D single-plane registration. To compare 3D motions between groups, we performed a two-way repeated measures analysis of variance.ResultsEight subjects were assigned to the high group, while seven subjects were assigned to the low groups based on an average elevation angle of 172°. The low group demonstrated a significant larger scapular protraction during elevation in all planes (P = 0.0002 for flexion; P = 0.0047 for scaption; P = 0.0314 for abduction), and smaller posterior tilting only during flexion (P = 0.0157). No significant differences occurred in scapular upward rotations or the glenohumeral positions and rotations.ConclusionsThis study revealed that insufficient scapular retraction and posterior tilting results in lower arm elevation angles, suggesting that improving the flexibility and activation of muscles surrounding the scapula may be important to achieve complete arm elevation.     

Evaluation of short-term and residual effects of Kinesio taping in chronic lateral epicondylitis: A randomized,double-blinded,controlled trial

BackgroundLateral epicondylitis is degenerative tendinosis of the extensor carpi radialis brevis muscle and is the most common work/sports-related chronic musculoskeletal problem affecting the elbow.PurposeThis study aimed to evaluate the short term and residual effectiveness of the Kinesio taping method on pain, grip force, quality of life, and functionality.Study DesignRandomized, double-blinded, controlled study.MethodsSubjects were 50 patients diagnosed with chronic unilateral lateral epicondylitis with a symptom duration of at least 12 weeks. During the first four weeks, the study group received a true inhibitor Kinesio taping while the control group received sham taping. In both groups, progressive stretching and strengthening exercises were given as a home program for six weeks. The primary outcome measure was the Numerical Rating Scale (NRS) for self-report of pain intensity; secondary outcome measures were Cyriax resistive muscle test evaluation, maximal grip strength, Patient- Rated Tennis Elbow Evaluation (PRTEE), and Short Form-36 (SF-36). After the treatment, patients were evaluated by the first assessor who was blinded to taping types.ResultsThere was a significant decrease in NRS scores overtime during the first four weeks in both groups (P < .001,) and effect sizes were large. There was no significant difference in Cyriax muscle resistance test maximal grip strength between groups (P > .05). However, there was a significant improvement in muscle strength of elbow extension and pronation in the study group detected in the intragroup analysis. Intragroup comparisons also showed a significant improvement in all subunits of the PRTEE and SF-36 except energy/vitality, social functioning, and pain in both groups (P < .05) with moderate to high effect sizes. PRTEE pain scores were significantly decreased in the study group compared to the placebo group (P < .05, d = 0.48).ConclusionThe effects of Kinesio taping on muscle strength, quality of life, and function in chronic lateral epicondylitis are not superior to placebo. However, NRS scores showed that in the two weeks after Kinesio taping treatment, pain reduction persisted as a residual effect which may improve the exercise adherence and functionality.     

不稳定性肩胛骨骨折的内固定治疗

目的:探讨不稳定性肩胛骨骨折的手术治疗方法及疗效。方法:自2008年10月至2011年8月收治不稳定性肩胛骨骨折14例,其中男12例,女2例;年龄21～55岁,平均38.7岁;伤后至就诊时间1h～10d,平均3d。肩胛体骨折3例,肩胛颈及肩胛体骨折4例,肩胛颈及肩峰端骨折4例,关节盂及喙突部骨折2例,肩胛冈及喙突部骨折1例。14例均采用手术治疗,术后采用Hardegger标准进行功能评定。结果:14例均获得随访,时间2～36个月,平均12.4个月。骨折临床愈合时间6～8周,无切口感染、内固定失败。根据Hardegger标准进行功能评定,优9例,良3例,可2例。结论:手术治疗不稳定性肩胛骨骨折可重建肩关节稳定,促进关节功能早期康复,最大限度地恢复肩关节功能。     

肩胛背神经卡压的应用解剖学研究

观察并分析腱性纤维束是否为造成肩胛背神经卡压的主要因素。方法：在３２侧成人尸体标本上，观测肩肿背神经的起源、走行、分支、分布及其与中斜角肌的解剖关系。结果：肩胛背神经７５％（２４／３２）从Ｃ５神经根发出；由前内侧向后外侧从中斜角肌穿过，其长度为１．２±０．３ｃｍ，在其内侧缘有大部分键性纤维组织存在。该神经除发出２～５支肌支外，另有２５％（８／３２）还发出细小分支走向肩背部。结论：中斜角肌内侧缘的限性结构特点是造成肩胛背神经卡压的形态学基础。     

Glenoid neck length in a healthy population and its association with scapular notching

BackgroundScapular notching is a radiographic finding associated with the use of a reverse shoulder prosthesis. The morphological characteristics of the glenoid neck have been scarcely explored as a relevant factor in relation to scapular notching. The objective of this study is to measure the length of the glenoid neck in a three-dimensional CT reconstruction of a healthy population and to simulate the scapular notching free range of motion for the “long neck” and for the “short neck” groups.MethodsCT scans of 214 shoulders were reviewed, excluding incomplete, poor quality, or altered studies. 100 CT scans were finally processed. The mean age was 51.7 years (SD 19.4; range, 15–84 years), with 49 female and 51 male patients. For each of the scapulae, four morphometric measurements were obtained: anterior glenoid neck (AGN), middle glenoid neck (MGN), posterior glenoid neck (PGN) and alternative posterior glenoid neck (aPGN). Using 3D software, we simulated a reverse shoulder prosthesis, and the scapular notching free range of motion was registered. Differences between measurements were evaluated with an unpaired t-test using StataIC16®. P-values < 0.05 were considered significant. The intraobserver and interobserver correlation was evaluated with the intraclass correlation coefficient.ResultsThe AGN measured 7.43 ± 2.52 mm (range, 1.72–13.3 mm); MGN measured 8.05 mm ± 1.93 (range, 2.92–13.2 mm); PGN measured 7.26 ± 2.6 mm (range, 2–13.4 mm); and aPGN measured 8.97 ± 2.3 mm (range, 4.08–15.4 mm). The scapular notching free range of motion for the “long neck” group was 74.98° ± 7.35 (range, 55–83°) and for the “short neck” group, it was 62.93° ± 6.84 (range, 45–70°) (p = 0.0004).ConclusionsMeasurement of posterior glenoid neck length exhibits excellent reliability and reproducibility, as well as being associated to the scapular notching free range of motion.Study designBasic, retrospective, CT images research.