Scapular-focused exercise treatment protocol for shoulder impingement symptoms: Three-dimensional scapular kinematics analysis

BackgroundThe present study aimed to describe the effects of a periscapular strengthening and neuromuscular training protocol in three-dimensional scapular kinematics and resting positioning in participants with shoulder impingement symptoms. Self-reported function was also evaluated.MethodThe study group comprised 50 subjects with shoulder impingement syndrome (control group, n = 25; treatment group, n = 25). The treatment group underwent 8 weeks of neuromuscular training and periscapular strengthening. Scapular kinematics was measured using an electromagnetic tracking device, and the Brazilian version of the Shoulder Pain and Disability Index (SPADI-Br) questionnaire was carried out before and after the treatment.FindingsIn the resting position, treated subjects had lower (p < 0.01) internal rotation of the scapula compared to the control group, with a large effect size (2.4). On the coronal plane, the treated group had less scapular upward rotation (p < 0.01) and less internal rotation (p < 0.05), with a medium effect size. On the sagittal plane, the treated group had less internal rotation (p < 0.01), less upward rotation (p < 0.05), and less scapular anterior tilt (p < 0.01), with a medium effect size. On the scapular plane, a reduction in upward rotation (p < 0.01) after the intervention was observed, with a large effect size. Moreover, a reduction in the total SPADI-Br score was found, with a mean difference of 32.4 [24.4; 40.4] points (p < 0.01) after the implementation of the protocol and a large effect size (2.0).InterpretationThe results provide biomechanical support for the clinical rationale for indicating therapeutic exercises focused on the periscapular muscles to improve scapular dynamics.     

Comparison of shoulder strength in males with and without myofascial trigger points in the upper trapezius

BackgroundThis study was conducted in order to compare the strength of scapular elevator and shoulder abductor with and without restricted scapular elevation between male subjects with and without myofascial trigger points in the upper trapezius.MethodsIn total, 15 male subjects with myofascial trigger points, and 15age- and weight-matched male subjects without myofascial trigger points in the upper trapezius. Each subject was measured in the strength of maximum isometric scapular elevation and shoulder abduction with and without restricted scapular elevation. Maximum isometric contractions were measured using the Smart KEMA strength measurement system. Independent t-tests were used to compare shoulder strength values between the myofascial trigger points and non- myofascial trigger points groups.FindingThe results showed that shoulder abductor strength in the group with myofascial trigger points (5.64 kgf) was significantly lower than in the group without myofascial trigger points (11.96 kgf) when scapular elevation was restricted (p < 0.05). However, there was no significant difference in the strength of the scapular elevator or shoulder abductor between groups (p > 0.05).InterpretationThese findings suggest that decreased strength in the shoulder abductor with restricted scapular elevation should be considered in evaluating and treating individuals with myofascial trigger points of the upper trapezius.     

Postural abnormalities in phenotypes of chronic obstructive pulmonary disease

BackgroundFew studies have demonstrated postural abnormalities in patients with chronic obstructive pulmonary disease - when compared with healthy individuals. However, none of these studies have compared postural abnormalities in different phenotypes of chronic obstructive pulmonary disease.ObjectiveTo compare the thoracic posture between two phenotypes of chronic obstructive pulmonary disease (emphysema and chronic bronchitis) with healthy individuals.MethodsForty individuals with chronic obstructive pulmonary disease (20 with chronic bronchitis, 67 ± 3.5 years, 20 with emphysema, 67.7 ± 4 years) and 20 age-matched healthy individuals (67.3 ± 3.9 years) underwent postural assessment which was performed using photogrammetric measurements of head protraction, shoulder protraction, thoracic kyphosis angle, coronal shoulder angle, and scapular elevation.ResultsSignificant differences were found amongst the groups in protraction of head (emphysema vs. chronic bronchitis, mean difference = 7.63°, 95% confidence interval [CI] = 2.10, 13.15°; emphysema vs. healthy, 7.91°, 95% CI = 2.38, 13.43°), protraction of shoulder (emphysema vs. healthy, 13.69°, 95% CI = 6.96, 20.43°; chronic bronchitis vs. healthy, 8.11°, 95% CI = 1.38, 14.85°), thoracic kyphosis (emphysema vs. healthy, −11.59°, 95% CI = −17.26, −5.92°; chronic bronchitis vs. healthy, −6.75°, 95% CI = −12.41, −1.08°), coronal shoulder angle (emphysema vs. chronic bronchitis, 1.01°, 95% CI = .22, 1.80°; emphysema vs. healthy, 1.59°, 95% CI = .80, 2.38°) and scapular elevation (emphysema vs. chronic bronchitis, =.74 cm, 95% CI = .34, 1.15 cm; emphysema vs. healthy, .99 cm, 95% CI = .59, 1.40 cm).ConclusionPeople with emphysema show greater degree of postural malalignments in terms of head and shoulder protraction, thoracic kyphosis, symmetry of shoulders and scapular elevation than patients with chronic bronchitis and age-matched healthy individuals. These observations emphasize the importance of postural assessment in individuals with chronic obstructive pulmonary disease, particularly if they are emphysematous.     

The effect of a scapular postural correction strategy on trapezius activity in patients with neck pain

Extensive computer use amongst office workers has lead to an increase in work-related neck pain. Aberrant activity within the three portions of the trapezius muscle and associated changes in scapular posture have been identified as potential contributing factors. This study compared the activity (surface electromyography) of the three portions of the trapezius in healthy controls (n = 20) to a neck pain group with poor scapular posture (n = 18) during the performance of a functional typing task. A scapular postural correction strategy was used to correct scapular orientation in the neck pain group and electromyographic recordings were repeated. During the typing task, the neck pain group generated greater activity in the middle trapezius (MT) (p = 0.02) and less activity in the lower trapezius (LT) (p = 0.03) than the control group. Following correction of the scapula, activity recorded by the neck pain group was similar to the control group for the middle and lower portions (p = 0.09; p = 0.91). These findings indicate that a scapular postural correction exercise may be effective in altering the distribution of activity in the trapezius to better reflect that displayed by healthy individuals.     

The effect of a rotator cuff tear and its size on three-dimensional shoulder motion

BackgroundRotator cuff-disease is associated with changes in kinematics, but the effect of a rotator cuff-tear and its size on shoulder kinematics is still unknown in-vivo.MethodsIn this cross-sectional study, glenohumeral and scapulothoracic kinematics of the affected shoulder were evaluated using electromagnetic motion analysis in 109 patients with 1) subacromial pain syndrome (n = 34), 2) an isolated supraspinatus tear (n = 21), and 3) a massive rotator cuff tear involving the supraspinatus and infraspinatus (n = 54). Mixed models were applied for the comparisons of shoulder kinematics between the three groups during abduction and forward flexion.FindingsIn the massive rotator cuff-tear group, we found reduced glenohumeral elevation compared to the subacromial pain syndrome (16°, 95% CI [10.5, 21.2], p < 0.001) and the isolated supraspinatus tear group (10°, 95% CI [4.0, 16.7], p = 0.002) at 110° abduction. Reduced glenohumeral elevation in massive rotator cuff tears coincides with an increase in scapulothoracic lateral rotation compared to subacromial pain syndrome (11°, 95% CI [6.5, 15.2], p < 0.001) and supraspinatus tears (7°, 95% CI [1.8, 12.1], p = 0.012). Comparable differences were observed for forward flexion. No differences in glenohumeral elevation were found between the subacromial pain syndrome and isolated supraspinatus tear group during arm elevation.InterpretationThe massive posterosuperior rotator cuff-tear group had substantially less glenohumeral elevation and more scapulothoracic lateral rotation compared to the other groups. These observations suggest that the infraspinatus is essential to preserve glenohumeral elevation in the presence of a supraspinatus tear. Shoulder kinematics are associated with rotator cuff-tear size and may have diagnostic potential.     

Muscle activation patterns in the scapular positioning muscles during loaded scapular plane elevation: The effects of Latent Myofascial Trigger Points

BackgroundLatent Myofascial Trigger Points are pain-free neuromuscular lesions that have been found to affect muscle activation patterns in the unloaded state. The aim was to extend these observations to loaded motion by investigating muscle activation patterns in upward scapular rotator muscles (upper and lower trapezius and serratus anterior) hosting Latent Myofascial Trigger Points simultaneously with lesion-free synergists for shoulder abduction (infraspinatus and middle deltoid). This approach allowed examination of the effects of these lesions on both their hosts and their lesion-free synergists in order to understand their effects on the performance of shoulder abduction.MethodsSurface electromyography was employed to measure the timing of onset of muscle activation of the upper and lower trapezius and serratus anterior (upward scapular rotators), infraspinatus (rotator cuff) and middle deltoid (abductor of the arm) initially without load and then with light (1–4 kg) dumbbells. Comparisons were made between control (no Latent Trigger Points; n = 14) and Latent Trigger Point (n = 28) groups.FindingsThe control group displayed a relatively stable sequence of muscle activation that was significantly different in timing and variability to that of the Latent Trigger Point group in all muscles except middle deltoid (all P < 0.05). The Latent Trigger Point group muscle activation pattern under load was inconsistent, with the only common feature being the early activation of the infraspinatus.InterpretationThe presence of Latent Trigger Points in upward scapular rotators alters the muscle activation pattern during scapular plane elevation, potentially predisposing to overuse conditions including impingement syndrome, rotator cuff pathology and myofascial pain.     

Implant impingement during internal rotation after reverse shoulder arthroplasty. The effect of implant configuration and scapula anatomy: A biomechanical study

BackgroundInternal rotation after reverse shoulder arthroplasty is essential to perform fundamental daily living activities. The purpose of this study was to examine the impact of anatomical and implant related factors on impingement-free internal rotation of the glenohumeral joint.MethodsCT-scans of 13 human shoulder specimens with implanted reverse shoulder prostheses were carried out and scapula neck length, lateral pillar angle, and implantation height of the metaglene were measured. Internal rotation testing of all specimens was performed by the use of a robot assisted shoulder simulator. Biomechanical variables were analyzed using a three-way ANOVA. Spearman's rank correlations were performed to determine the relationship between biomechanical and anatomical data.FindingsThe maximum internal rotation angle for a 38 mm centric glenosphere and a standard onlay was 93.4(SD 34.9°). The change of the diameter of the glenosphere resulted in no significant increase of the maximum rotation angle (P = 0.16), while change of the glenosphere type from concentric to eccentric (P = 0.005) as well as the change of the onlay type from standard to a more shallow one (P = 0.002) both had a significant effect on the internal rotation.The distance between the inferior rim of the metaglene and the inferior aspect of the glenoid (P = 0.21), scapula pillar angle (P = 0.13) as well as the scapula neck length (P = 0.81) showed no significant correlation with the maximum internal rotation angle.InterpretationImplant component selection shows strong influence on the impingement-free internal rotation. The use of an eccentric glenosphere and a shallow humeral cup may improve internal rotation after reverse shoulder arthroplasty.     

Quantifying acromiohumeral distance in elite male field hockey players compared to a non-athletic population

BackgroundShoulders of elite field hockey players are loaded continuously during play. Frequent high shoulder loading is known to influence certain shoulder variables, such as acromiohumeral distance. However, the influence of elite field hockey play on acromiohumeral distance is not examined yet.ObjectiveTo examine the acromiohumeral distance in elite male field hockey players compared to a non-athletic control group.DesignCross-sectional study.MethodsFifty male participants were included; 25 elite field hockey players (age: 24.0 ± 2.72 years; weight: 77.2 ± 5.29 kg; height; 180.5 ± 5.37 cm) and 25 age- and gender matched non-athletes (23.0 ± 2.29 years; weight: 75.7 ± 9.53 kg; height: 181.8 ± 5.52 cm). A Telemed-Colormaster-128 EXT-IZ device was used to bilaterally obtain ultrasound acromiohumeral distance images at 3 different angles of shoulder abduction in the frontal plane.ResultsField hockey players showed a bilateral larger acromiohumeral distance at 45° (mean difference: 1.46 mm [95% CI 0.46; 2.46]; p = 0.005) and 60° (mean difference: 1.07 mm [95% CI 0.21; 1.93]; p = 0.016) compared to controls. In both groups, a significant but clinically less relevant, side difference was established for the acromiohumeral distance at 60° (mean difference: 0.79 mm [95% CI 0.21; 1.34]; p = 0.009).ConclusionWith active shoulder abduction, elite field hockey players show a larger acromiohumeral distance in comparison to non-athletic participants. This may be a protective sport-specific adaptation, to better guard the shoulder from injury. Thus, acromiohumeral distance measurement may help physical therapists/coaches decide which athletes could benefit from specific, additional exercises aimed at enlarging the subacromial space.     

Acupuncture treatment of shoulder impingement syndrome: A randomized controlled trial

BackgroundShoulder pain or omalgia is one of the main types of osteoarticular pain that can be observed in every-day clinical practice, frequently causing significant functional impairment. The most common cause of shoulder pain is impingement syndrome.ObjectiveTo decrease the intensity of short- and mid-term pain in the injured shoulder by means of acupuncture.MethodRandomized controlled trial with two groups of participants: one group received true acupuncture (TA) and the other received acupuncture at sham points (SA). The treatment was carried out over 4 weeks, with the participants receiving a session every week. The results were measured immediately after the treatment (T1) and 3 months later (T2). To evaluate the results, we used the 100 mm Visual Analogue Scale (VAS), and to assess the functionality of the shoulder we employed the UCLA questionnaire (0–35 points).ResultsA total of 68 participants were included in the analysis (TA, n = 35; SA, n = 33), with a mean age of 33.4 years (SD 12.53). We found significant differences in the analyzed results between the two groups, as we observed a decrease on the intensity of pain for the TA group of 44.13 mm at T1 (CI 95% 36.7; 51.5) and 87.58 mm at T2 (CI 95% 28.32; 46.81), while the decrease in the FA group was of 19.84 mm at T1 (CI 95% 12.2; 27.4) and 20 mm at T2 (CI 95% 10.9; 29.09). When the UCLA scores were analyzed, the results were clinically meaningful in support of TA in terms of functional assessment of the shoulder. No adverse effects were reported.ConclusionsThe use of acupuncture to treat impingement syndrome seems to be a safe and reliable technique to achieve clinically significant results and could be implemented in the therapy options offered by the health services.     

Scapular kinematics and impairment features for classifying patients with subacromial impingement syndrome

Subacromial impingement syndrome (SAIS), which is associated with pain and a loss of function, has a high occurrence in the physically active population. Not all patients respond positively to treatment. Classifying patients can improve decision-making. The scapular kinematic and clinical impairments can aid in classifying the patients who are more likely to respond to physical therapy treatment. Thirty-three subjects (males, 20–33 years) presenting SAIS were studied to determine altered scapular kinematics and clinical impairments. Three measurements were collected: (1) three-dimensional scapular kinematics during performing functional tasks; (2) impairment outcomes of range of motion and muscle force; and (3) self-reported measurements of pain, satisfaction, and function. All patients received 6-week (2 times per week) physical therapy treatment. Improvement with treatment was determined using the Global Rating of Change Scale. Scapular kinematics and clinical impairments were first identified by t-test in predicting improvement and then combined into a multivariate prediction method. A prediction method with three variables (Flexilevel Scale of Shoulder Function score < 41, muscle power of serratus anterior < 27.4% body weight, degree of scapular internal rotation at 30° shoulder elevation during descending arm phase in unloaded condition < 0.7°) were identified. It appears that scapular kinematics and impairment features can be used to classify subjects with SAIS in addition to self-report. Prospective validation of the proposed prediction method requires further investigation.     

Influence of reducing anterior pelvic tilt on shoulder posture and the electromyographic activity of scapular upward rotators

BackgroundModifications of posture in a segment may influence the posture of adjacent and nonadjacent segments and muscular activity. The spine–shoulder and spine–pelvis relationships suggest that the pelvis may influence shoulder posture.ObjectiveTo investigate the effect of the active reduction of the anterior pelvic tilt on shoulder and trunk posture during static standing posture and on the electromyographic activity of the scapular upward rotators during elevation and lowering of the arm.MethodsThirty-one young adults were assessed in a relaxed standing position and a standing position with 30% active reduction of the anterior pelvic tilt. The pelvic tilt, trunk posture, and forward shoulder posture during the static standing posture and the electromyographic activity during elevation and lowering of the arm were assessed.ResultsPaired t-tests indicated that the active reduction of the anterior pelvic tilt reduced the trunk extension (MD = 1.09; 95%CI = −2.79 to −1.03). There were no effects on the forward shoulder posture (MD = 0.09; 95%CI = −0.92 to 1.09). Repeated measures of analyses of variance indicated an increase in lower trapezius electromyographic activity (MD = 3.6; 95%CI = 1.28 to 5.92). There was a greater reduction in upper trapezius activity after pelvic tilt reduction during arm elevation (MD = 1.52%; 95%CI = −2.79 to −0.25) compared to that during the lowering phase. There were no effects of pelvic tilt reduction on the electromyographic activity of the serratus anterior (MD = 3.26; 95%CI = −3.36 to 9.87).ConclusionThe influence of pelvic posture on the trunk posture and lower trapezius activation should be considered when assessing or planning exercise for individuals with shoulder or trunk conditions.     

Hip kinematics and kinetics in persons with and without cam femoroacetabular impingement during a deep squat task

BackgroundPrevious studies have indicated that hip and pelvis kinematics may be altered during functional tasks in persons with femoroacetabular impingement. The purpose of this study was to compare hip and pelvis kinematics and kinetics during a deep squat task between persons with cam femoroacetabular impingement and pain-free controls.MethodsFifteen persons with cam femoroacetabular impingement and 15 persons without cam femoroacetabular impingement performed a deep squat task. Peak hip flexion, abduction, and internal rotation, and mean hip extensor, adductor, and external rotator moments were quantified. Independent t-tests (α < 0.05) were used to evaluate between group differences.FindingsCompared to the control group, persons with cam femoroacetabular impingement demonstrated decreased peak hip internal rotation (15.2° (SD 9.5°) vs. 9.4° (SD 7.8°); P = 0.041) and decreased mean hip extensor moments (0.56 (SD 0.12) Nm/kg vs. 0.45 (SD 0.15) Nm/kg; P = 0.018). In addition persons in the cam femoroacetabular impingement group demonstrated decreased posterior pelvis tilt during squat descent compared to the control group, resulting in a more anteriorly tilted pelvis at the time peak hip flexion (12.5° (SD 17.1°) vs. 23.0° (SD 12.4°); P = 0.024).InterpretationThe decreased hip internal rotation observed in persons with cam femoroacetabular impingement may be the result of bony impingement. Furthermore, the decrease in posterior pelvis tilt may contribute to impingement by further approximating the femoral head–neck junction with the acetabulum. Additionally, decreased hip extensor moments suggest that diminished hip extensor muscle activity may contribute to decreased posterior pelvis tilt.     

Concurrent validity of handheld dynamometer measurements for scapular protraction strength

BackgroundHandheld dynamometers (HHD) provide quick and low-cost assessments of muscle strength and their use has been increasing in clinical practice. There is no available data related to the validity of HHD for this measurement.ObjectiveTo verify the concurrent validity of scapular protraction measurements using an HHD.MethodsIndividuals with traumatic anterior glenohumeral instability were allocated in Instability Group (n = 20), healthy swimmers were allocated in Athletes Group (n = 19) and healthy subjects were allocated in Sedentary Group (n = 21). Concurrent validity was verified by the Pearson correlation test between HHD and isokinetic measurements. The agreement between instruments was verified by Bland–Altman plots, for each of the two HHD positions.ResultsA moderate correlation was observed between seated (r = 0.59) and lying supine HHD (r = 0.54) and isokinetic dynamometer measurements for the all groups. Separated group analysis exhibited a strong correlation between seated HHD and isokinetic dynamometer measurements in the Instability Group (r = 0.80), Sedentary Group (r = 0.79) and Athletes Group (r = 0.76). The Bland–Altman plot showed greater agreement in the seated position than the lying supine position when comparing measurements with the HHD and isokinetic in both the general sample and separated groups.ConclusionThe HHD may be considered a valid tool for assessing scapular protraction muscle strength among healthy athletes, non-athletes and subjects with shoulder instability. We recommend to assess subjects in the seated position and to be aware that the HHD tends to overestimate the peak force, compared with the gold-standard isokinetic dynamometer.     

Prevalence of gastric parietal cell antibodies and intrinsic factor antibodies in primary biliary cirrhosis

BackgroundWe investigated the prevalence of antibodies against gastric parietal cells (GPA), intrinsic factor antibodies (IFA) and the presence of pernicious anemia in a large cohort of primary biliary cirrhosis (PBC) patients as similar data is missing.Methods157 PBC patients and 357 controls (73 with autoimmune hepatitis (AIH), 35 primary sclerosing cholangitis (PSC), 45 HBV, 37 HCV, 36 alcoholic liver disease (ALD), 35 non-alcoholic fatty liver disease (NAFLD) and 96 healthy) were investigated for IgG-isotype-specific GPA and IFA by ELISAs and vitamin-B₁₂ levels by a microparticle enzyme immunoassay.ResultsThe detection of IgG-GPA was significantly higher in PBC (31.8%) compared to AIH (10.9%; p = 0.001), PSC (0%; p = 0.000), HCV (13.5%; p = 0.01), HBV (13.3%; p = 0.006), ALD (8.3%; p = 0.004), NAFLD (11.4%; p = 0.003) and healthy (10.4%; p = 0.001). IgG-IFA were detected in 12% of GPA-positive PBC patients and in none of the other liver diseases or in healthy (p = 0.001). This reactivity was significantly associated with lower vitamin-B₁₂ levels compared to those with an IFA-negative test (p = 0.025).ConclusionsA significant proportion of PBC patients had IgG-GPA and IFA compared to controls. IgG-IFA were detected only in GPA-positive PBC patients and associated with lower vitamin-B₁₂ levels compared to those with an IFA-negative test.     

Coupling between 3D displacements and rotations at the glenohumeral joint during dynamic tasks in healthy participants

BackgroundGlenohumeral displacements assessment would help to design shoulder prostheses with physiological arthrokinematics and to establish more biofidelic musculoskeletal models. Though displacements were documented during static tasks, there is little information on their 3D coupling with glenohumeral angle during dynamic tasks. Our objective was to characterize the 3D glenohumeral displacement–rotation couplings during dynamic arm elevations and rotations.MethodsGlenohumeral displacements were measured from trajectories of reflective markers fitted on intracortical pins inserted into the scapula and humerus. Bone geometry was recorded using CT-scan. Only four participants were recruited to the experiment due to its invasiveness. Participants performed dynamic arm abduction, flexion and axial rotations. Linear regressions were performed between glenohumeral displacements and rotations. The pin of the scapula of one participant moved, his data were removed from analysis, and results are based on three participants.FindingsThe measurement error of glenohumeral kinematics was less than 0.15 mm and 0.2°. Maximum glenohumeral displacements were measured along the longitudinal direction and reached up to + 12.4 mm for one participant. Significant couplings were reported especially between longitudinal displacement and rotation in abduction (adjusted R² up to 0.94).InterpretationThe proposed method provides the potential to investigate glenohumeral kinematics during all kinds of movements. A linear increase of upward displacement during dynamic arm elevation was measured, which contrasts with results based on a series of static poses. The systematic investigation of glenohumeral displacements under dynamic condition may help to provide relevant recommendation for the design of shoulder prosthetic components and musculoskeletal models.     

Gender difference of shoulder-pelvic kinematic integration for trunk rotation directions in healthy older adults

BackgroundThe trunk coordination pattern has been extensively studied, and there is a higher pain prevalence and asymmetry in female older adults. However, there is a lack of investigation of different directions of trunk rotation and asymmetrical compensatory strategies of motor control between genders. The purpose of this study was to investigate shoulder and pelvic ranges of motion (ROM) as well as relative phases (RP) for the different directions of trunk rotation between genders in healthy older adults.MethodsThere were 62 right hand dominant older adults in this study (31 female subjects (68.4 [5.62] years) and 31 male subjects (68.7 [5.68] years)). The participants performed trunk axial rotation from the left to the right direction (RP1) and then returned to the left side (RP2), three times repeatedly in standing. The measurements included shoulder and pelvic ROM, RP1, and RP2. The RP was defined as the average absolute relative phase, which was the difference between the phase angle of the shoulder and the phase angle of the pelvis during trunk rotation.FindingsThe female group demonstrated significantly greater pelvic rotation compared to the male group (98.64 [24.67] vs. 86.96 [18.97]; t = 2.09, p = 0.04) during trunk rotation. The pelvic ROM demonstrated a significant positive correlation with shoulder ROM in both genders; however, the RP was negatively correlated with the pelvis. For pelvic rotation, the male group demonstrated a negative correlation with RP1 (r = − 0.68, p < 0.01) and RP2 (r = − 0.60, p < 0.01) while the female group demonstrated a negative correlation with RP2 (r = − 0.53, p < 0.01). The ageing factor demonstrated negative correlations with ROM for the shoulder and pelvis in both genders.InterpretationAlthough no gender difference was indicated on the direction of RP, the pelvic ROM was significantly lesser in the male group. The male group demonstrated lesser pelvic rotation in both directions of rotation; however, the female group showed lesser pelvic rotation in RP2. The male group demonstrated stiffened pelvic rotation and greater shoulder rotation in both directions while the female group demonstrated pelvic stiffness only in the direction from right to left rotation. Clinicians need to consider this directional asymmetry of trunk rotation to enhance integrated shoulder-pelvic coordination in female older adults.Mini abstractA coordinative pattern of different directions of trunk rotation was investigated in healthy older adults. The pelvic range of motion was lesser in the male group compared with the female group. The female group demonstrated pelvic stiffness only in the direction from right to left rotation, while the male group demonstrated pelvic stiffness in both directions. Clinicians need to understand the gender difference of directional coordination as integrated coordination in female older adults.     

Neuromuscular rate of force development deficit in Parkinson disease

BackgroundBradykinesia and reduced neuromuscular force exist in Parkinson disease. The interpolated twitch technique has been used to evaluate central versus peripheral manifestations of neuromuscular strength in healthy, aging, and athletic populations, as well as moderate to advanced Parkinson disease, but this method has not been used in mild Parkinson disease. This study aimed to evaluate quadriceps femoris rate of force development and quantify potential central and peripheral activation deficits in individuals with Parkinson disease.MethodsNine persons with mild Parkinson Disease (Hoehn & Yahr ≤ 2, Unified Parkinson Disease Rating Scale total score = mean 19.1 (SD 5.0)) and eight age-matched controls were recruited in a cross-sectional investigation. Quadriceps femoris voluntary and stimulated maximal force and rate of force development were evaluated using the interpolated twitch technique.FindingsThirteen participants satisfactorily completed the protocol. Individuals with early Parkinson disease (n = 7) had significantly slower voluntary rate of force development (p = 0.008; d = 1.97) and rate of force development ratio (p = 0.004; d = 2.18) than controls (n = 6). No significant differences were found between groups for all other variables.InterpretationsPersons with mild-to-moderate Parkinson disease display disparities in rate of force development, even without deficits in maximal force. The inability to produce force at a rate comparable to controls is likely a downstream effect of central dysfunction of the motor pathway in Parkinson disease.     

Scapular kinematics in professional wheelchair tennis players

BackgroundParticipating in wheelchair tennis increases the demands placed on the shoulder and could increase the risk of developing shoulder pain and injury that might be associated with differences in scapular kinematics. The aim of the study was to examine the presence of shoulder pain and scapular kinematics in professional wheelchair tennis players.MethodScapular kinematics were obtained in 11 professional wheelchair tennis players, 16 people with shoulder impingement and 16 people without shoulder impingement during humeral elevation and lowering. Clinical examination of the wheelchair tennis players was undertaken using the Wheelchair Users Shoulder Disability Index (WUSPI) and clinical signs of shoulder impingement.FindingsThe WUSPI questionnaire (mean = 28 SD 13.8) demonstrated wheelchair tennis participants experienced little shoulder pain and clinical examination revealed negative impingement tests. Wheelchair tennis players had greater scapular posterior tilt during humeral elevation (3.9° SE 1.71; P = 0.048) and lowering (4.3° SE 1.8; P = 0.04) on the dominant compared to non-dominant side. The dominant scapulae of wheelchair tennis players were significantly (P = 0.014) more upwardly rotated (21° SD 6.7) than the scapulae of people with shoulder impingement (14.1° SD 7.0) during scapular plane humeral elevation.InterpretationThis first study of scapular kinematics in professional wheelchair tennis athletes demonstrated bilateral asymmetries and differences to able-bodied participants with shoulder impingement. Understanding the role of sport participation on shoulder function in wheelchair users would assist in the development of preventative and treatment exercise programmes for wheelchair users at risk of shoulder injury and pain.     

Shoulder and elbow kinematics during the Mallet score in obstetrical brachial plexus palsy

BackgroundThe physical signs of obstetrical brachial plexus palsy range from temporary upper-limb dysfunction to a lifelong impairment and deformity in one arm. The aim of this study was to analyze the kinematics of the upper limb and to evaluate the contribution of glenohumeral and scapulothoracic joints of obstetrical brachial plexus palsy children.MethodsSix children participated in this study: 2 males and 4 females with a mean age of 11.7 years. Three patients had a C5, C6 lesion and 3 had a C5, C6, C7 lesion. They were asked to perform five tasks based on the Mallet scale and the kinematic data were collected using the Fastrak electromagnetic tracking device.FindingsThe scapulothoracic protraction and posterior tilt were significantly increased in the involved limb during the hand to mouth task (p = 0.006 and p = 0.015 respectively). The scapulothoracic Protraction/glenohumeral Elevation ratio was significantly increased in the involved limb during the hand to neck task (p = 0.041) and the elevation task (p = 0.015). The ratios of scapulothoracic Tilt on the three glenohumeral excursion angles were significantly increased during the hand to mouth task (p ≤ 0.041). The scapulothoracic Mediolateral/glenohumeral Elevation ratio was significantly increased in the involved limb during the elevation task (p = 0.038). The glenohumeral elevation excursion was significantly decreased in the involved limb during the hand to neck task (p < 0.001) and the elevation task (p = 0.0003).InterpretationThis study gives us information about the greater contribution of the scapulothoracic joint to shoulder motion for affected arm of obstetrical brachial plexus palsy patients compared to their unaffected arm. Kinematic analysis could be useful in shoulder motion evaluation during the Mallet score and to evaluate outcomes after surgery.