Maximum Abduction Research Articles

Hip Manipulation Increases Electromyography Amplitude and Hip Joint Performance: A Double-Blind Randomized Controlled Study

(1) Background: Activation of the gluteus medius (GM) muscle while minimizing the involvement of the tensor fascia latae (TFL) is crucial in treating many lower limb and lumbar spine injuries. Previous studies have demonstrated the effectiveness of joint manipulations in regulating muscle activity. The main objective of this study was to evaluate the effects of hip joint manipulation (HJM) on the muscle strength and activity (GM and TFL) of hip abductors in asymptomatic young participants. (2) Methods: The study followed a double-blind randomized controlled design. Thirty healthy, physically active women and men, free from spinal and lower limb injuries, voluntarily participated. The participants were allocated to two groups: those allocated to the HJM intervention and those in the control group receiving a sham intervention. They were assessed before and after the intervention using surface electromyography to measure muscle activation (EMGRMS) of the GM and TFL during maximal voluntary isometric hip abduction. (3) Results: HJM resulted in a significant increase in EMGRMS amplitude solely within the GM muscle (p < 0.01); (4) Conclusions: This study suggests that HJM may increase EMGRMS amplitude in the GM muscle; however, the effects are neither statistically nor clinically significant when compared to the control group for most of the muscles analyzed.

A Single Bout of On-Ice Training Leads to Increased Interlimb Asymmetry in Competitive Youth Hockey Athletes.

Interlimb asymmetry (ILA) refers to an anatomical or physiological imbalance between contralateral limbs, which can influence neuromuscular function. Investigating the influence of neuromuscular fatigue on ILA may be critical for optimizing training programs, injury rehabilitation, and sport-specific performance. The purpose of this study was to determine if a single bout of ice hockey-specific exercise creates or exacerbates lower-limb ILA. Before and after an on-ice training session, 33 youth ice-hockey athletes (14.9 [1.7]y; 11 females) performed 3 repetitions of a maximal vertical countermovement jump (CMJ), an eccentric hamstring contraction, and maximal isometric hip adduction and abduction contractions. Force- and power-related variables were analyzed to determine limb-specific neuromuscular function. The on-ice session reduced maximal isometric hip adduction (left: 7.3% [10.3%]; right: 9.5% [9.6%]) and abduction (left: 4.9% [6.9%]; right: 5.0% [8.1%]) force, but did not impair (P ≥ .10) CMJ performance (jump height, relative peak power, braking duration, and total duration). After the on-ice session, ILA was greater for CMJ propulsive impulse (6.3% [2.9%] vs 5.1% [2.6%]), CMJ braking rate of force development (19.3% [7.6%] vs 15.2% [6.4%]), and peak isometric hip adduction force (6.7% [5.5%] vs 6.1% [4.1%]). In conclusion, hockey-specific exercise leads to increased ILA for multiple force-related metrics, which may be a compensatory mechanism to maintain bilateral task performance when fatigued.

Effect of Glenohumeral Abduction on Supraspinatus Tendon Strain: A Cadaveric Study

Objectives Rotator cuff tears are among the most common causes of shoulder pain and loss of function in adults. The supraspinatus tendon plays a crucial role in shoulder abduction, where a better understanding of the mechanical environment could lead to more informed clinical decisions. This study aimed to examine the heterogeneous nature of the supraspinatus tendon to understand the differences in regional strain patterns. Methods Five fresh frozen cadaveric shoulders were abducted from 60° to 90°. The supraspinatus tendon was loaded at 30 newtons to simulate motion in a subject operating at roughly 26% of the maximum glenohumeral abduction force. The surface strain at the supraspinatus tendon insertion, where tears most commonly occur, was evaluated in the tendon’s anterior, middle, and posterior regions to identify the heterogeneous deformation during abduction. Results Surface strain increased with increasing abduction angle (R2 = 0.697, P < 0.001). The posterior regions exhibited larger strains compared to the anterior regions at 70° (P = 0.037), 75° (P = 0.028), and 90° (P = 0.011) of abduction. Conclusion During abduction, the strain on the bursal surface of the supraspinatus tendon insertion increases with increasing abduction angle, and the posterior region experiences the largest strains.

Adolescent Shoulder Reconstruction Techniques in Brachial Plexus Birth Injury

Brachial plexus birth injury (BPBI) is common and while most recover, 8-36% of patients experience permanent impairment. Typically, adolescents with untreated BPBI lack active and passive external shoulder rotation (ER) and overhead shoulder function. Limited shoulder function is due to 1) nonoperative BPBI 2) untreated BPBI or 3) unrecognized glenohumeral joint dysplasia. We describe a technique for achieving reanimation in adolescents who did not receive timely/effective BPBI care, a postoperative rehabilitation protocol, and results from a series of eight patients who underwent shoulder reanimation. A comprehensive shoulder reanimation approach is performed. Anteriorly, the pectoralis minor, major, and anterior capsule necessitate release. In severe dysplasia, a coracoidectomy, posterior glenoid osteotomy, and/or subscapularis slide may be necessary. Acromial dysplasia is also common, frequently necessitating osteoplasty. The deltoid is usually nonfunctional, and we use a bipolar latissimus muscle transfer for reanimating abduction and forward flexion. To assist with ease of rehabilitation we will often transfer the tendon of the teres major. Levator scapulae transfer to the supraspinatus is often performed to assist with the initiation of abduction. For external rotation, the ipsilateral lower trapezius is used. Finally, ipsilateral rhomboid advancement and contralateral lower trapezius muscle transfer is performed for dynamic scapular stabilization. After surgery, all patients participated in our rigorous postoperative rehabilitation protocol. Eight patients (13.8±5.6 years, 35±24 weeks follow-up) were included. All patients participated in our rehabilitation protocol. Preoperatively, patients generally achieved 0° ER from neutral and in maximum abduction. Postoperatively, patients achieved an average of 71° (30-90°) ER from neutral and an average of 82° (65-90°) ER in maximum abduction. Preoperatively, patients generally had 0-20° of abduction, which they achieved through scapulothoracic motion. Postoperatively, patients could achieve an average of 115° (90-180°) of abduction. Preoperatively, patients had 0-20° of FF that was mediated through scapulothoracic motion. Postoperatively, patients' FF increased to an average of 91° (20-170°). This technique is intended to restore a congruent glenohumeral joint and reanimate structures allowing for abduction, FF, and ER. While we advocate for early treatment of BPBI, applying this technique to undertreated/untreated adolescent patients paired with our rehabilitation protocol results in significant functional improvement, allowing for an improved quality of life.

The relationship of hip strength to walking and balance performance in unilateral lower limb prosthesis users differs by amputation level.

Safe and efficient locomotion is a frequently stated goal of lower limb prosthesis users, for which hip strength may play a central yet poorly understood role. Additional research to identify associations between hip strength, balance, and mobility among transtibial and transfemoral prosthesis users is required. To test whether residual and/or intact limb isometric hip strength was associated with lower limb prosthesis users' walking speed, endurance, and balance. Cross-sectional study. Research laboratory. Convivence sample of 14 transtibial and 14 transfemoral prosthesis users. Multiple linear regression was used to evaluate the relationship between isometric measures of residual and intact limb hip strength and walking and balance performance. Measures of isometric hip muscle strength, including peak torque, average torque, torque impulse, and torque steadiness (i.e. consistency with which an isometric torque can be sustained) were derived from maximum voluntary hip flexion, extension, abduction and adduction torque signals collected with a motor-driven dynamometer. Walking speed, endurance, and balance were assessed by administering the 10-meter walk test, 2-minute walk test, Four Square Step Test, and Narrowing Beam Walking Test, respectively. Residual limb hip extensor max torque and abductor torque steadiness explained between 51% and 69% of the variance in transtibial prosthesis users' walking speed, endurance, and balance. In contrast, intact limb hip abductor torque impulse explained between 33% and 48% of the variance in transfemoral prosthesis users' walking speed, endurance, and balance. Our results suggest that unilateral transtibial and transfemoral prosthesis users' walking and balance performance may depend on different hip muscles, and different facets of hip strength. Amputation level-specific hip strength interventions may therefore be required to improve walking and balance performance in unilateral transtibial and transfemoral prosthesis users. The "intact leg strategy" adopted by transfemoral prosthesis users may be due to a variety of prosthesis and biomechanical factors that limit the efficiency with which transfemoral prosthesis users can exploit the strength of their residual limb hip muscles while walking.

Measurement and observation of the first web space based on morphology and clinical applications

PurposeTo describe and evaluate the anatomical skin shape of the first web space in cadavers, and to guide flap design for this area. Methods12 cadavers (24 hands on both sides) were selected. Marker points were chosen based on the characteristics of the first web for morphological measurement and observation. The morphological characteristics of the first web under the radial or palmar abduction position of the thumb were measured and compared. The best morphologic feature and parameters of the first web repairing flap were obtained. ResultsWhen the thumb is in the palmar abduction position, the maximum distance a(p) is 6.78±0.72cm, and the skin area s(p) is 20.09±2.63cm2, both of which are significantly greater than the distance a(r) of 5.86±0.74cm and the skin area s(r) of 17.39±2.15cm2 when the thumb is in the radial abduction position (P<0.05). There was no significant difference in the length b(r) and b(p) of the long axis of the flap between two different abduction positions (P>0.05). It is found that the shape of the first web area is not a symmetrical spindle, but an irregular quadrilateral inclined to the index finger side. ConclusionThe flap design and measurement for the first web space covering should take the maximum palmar abduction position of the thumb as a reference. The asymmetric quadrilateral flap design is more in line with the anatomical and morphological characteristics of the region.

Relationship between hip contact force during gait and patient-reported outcome measures 6 months after total hip arthroplasty

PurposeEvaluating the hip contact force (HCF) during gait is important for assessing treatment outcomes after total hip arthroplasty (THA). This study investigated the relationship between patient-reported outcome measures (PROMs) and HCF during gait after THA as well as gait biomechanical factors affecting HCF during gait in relation to PROMs. MethodsIn total, 29 female patients who underwent THA with a 6-month follow-up were included in this study. Musculoskeletal model analysis was performed to obtain the first and second peak values of the HCF during gait and the minimum value between both peaks. PROMs were evaluated using the Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ). The relationship between JHEQ and selected HCFs and between the HCF and gait biomechanical factors was examined. ResultsThe second peak value of HCF was positively related to the total JHEQ, movement, and mental health scores (r ​= ​−0.551, 0.410, and 0.495, respectively). A positive relationship was found between the second peak value of the HCF and hip flexion–extension range of motion (r ​= ​0.518), maximum hip abduction moment (r ​= ​0.432), and maximum knee extension moment (r ​= ​0.417). A negative relationship was found between the second peak value of the HCF and the maximum knee abduction moment (r ​= ​−0.458). ConclusionsThe second peak value of HCF during gait after THA was related to PROMs. The second peak value was related to the hip flexion–extension range of motion, maximum hip abduction moment, and maximum knee extension and abduction moment.

Greater distance from the glenosphere center to the acromion reduces risk of acromial impingement in semi-inlay reverse shoulder arthroplasty

BackgroundRecently, the issue of subacromial notching, caused by acromial impingement has been reported. The purpose of this study was to assess the impact of differences in the distance between the glenosphere center and the greater tuberosity (DGT) and the distance between the glenosphere center and the acromion (DA) on the closest distance between the greater tuberosity and the acromion during active abduction in shoulders with reverse total shoulder arthroplasty (RSA). MethodsEleven shoulders with semi-inlay RSA were analyzed. Subjects underwent fluoroscopy during active scapular plane abduction. Computed tomography of their shoulders was performed to create 3-dimensional implant models at a mean of 16 months after surgery. Using model-image registration techniques, poses of 3-dimensional implant models were iteratively adjusted to match their silhouettes with the silhouettes in the fluoroscopic images (shape matching), and 3-dimensional kinematics of implants were computed. The closest distance between the acromion and greater tuberosity was computed at maximum abduction. DA and DGT were measured from 3-dimensional surface models. Shoulders were divided into two groups based on DA and DGT measurements and their closest distance data were compared between the groups. ResultsThere were 7 shoulders with DA ≥ DGT, and 4 shoulders with DA < DGT. Shoulders with DA ≥ DGT showed a significantly wider distance between the greater tuberosity and acromion at maximum abduction compared to those with DA < DGT (5.9 ± 2.4 mm vs. 0.6 ± 0.7 mm, respectively, P = 0.0021). There were no significant differences in maximum glenohumeral abduction angle and humeral abduction angle between the two groups. Although DA was significantly greater in shoulders with DA ≥ DGT than in those with DA < DGT (43.7 ± 4.4 mm vs. 35.1 ± 6.7 mm, respectively, P = 0.0275), there was no significant difference in DGT between the two groups. ConclusionsWhen DGT is less than DA in shoulders with RSA, the closest distance between the greater tuberosity and the acromion at maximum abduction is significantly wider compared to cases where DGT is greater than DA by 3-dimensional measurement. Therefore, acromial impingement is less likely to occur in shoulders with RSA when DA is greater than DGT. To avoid acromial impingement, it might be important to make DA greater than DGT.

Kinematic Effects of Derotational Osteotomy of the Humerus in Patients with Internal Shoulder Contracture Secondary to Erb's Palsy-A Retrospective Cohort Study.

Background: Internal rotation contractures of the shoulder are common sequelae of conservatively treated obstetric brachial plexus palsy (OBPP) with incomplete spontaneous neurological recovery. Humerus derotation osteotomy has been suggested as a possible treatment option to improve arm positioning. However, consensus as to whether humerus derotation osteotomy can successfully restore limb function is missing. Methods: In the present controlled cohort study, we aimed at analyzing global upper extremity kinematics with a 3D-video analysis system in children with shoulder internal rotation contractures secondary to OBPP before, and one year after, humerus derotation osteotomy. Patients under 18 years of age that presented to our center with conservatively treated internal rotation contractures of the shoulder and subsequently underwent humerus derotation osteotomy were included. The unimpaired arm served as a respective control. Results: Pre-operatively, all patients showed severe internal rotation contractures of the shoulder of almost 60° at rest. At the follow-up, the position of the shoulder at rest was greatly shifted to 9° of internal rotation. The patients showed statistically significant improvement in maximum external rotation and abduction of the shoulder, as well as in maximum flexion of the elbow, and the range of motion of pro/supination. The maximum internal rotation of the shoulder, however, was diminished after the osteotomy. Conclusions: Our data indicated that derotational osteotomy is a promising procedure which can be used to correct for internal rotation contractures secondary to OBPP. Moreover, 3D-video analysis proved to be a useful tool that supplies the surgeon with both precise information about the degree of distortion pre-operatively, thus helping to decide on the amount of correction, and secondly, a measurement of the post-operative gain in upper extremity function.

Unilateral laser ventriculocordectomy results in increased arytenoid stability in horses with severe left sided recurrent laryngeal neuropathy.

There is no objective information reporting the effect of unilateral laser ventriculocordectomy (VeC) on arytenoid abduction or stability. To evaluate arytenoid stability and abduction in horses with severe recurrent laryngeal neuropathy (RLN) before and after unilateral laser VeC. Prospective cohort. Eight horses with grade C or D exercising laryngeal function that underwent unilateral laser VeC were included. Exercising endoscopy was performed before and ≥6 weeks after left-sided laser VeC. Arytenoid stability at maximal exercise was calculated by measuring the left-to-right quotient angle ratio (LRQ) of the corniculate processes at the points of maximal arytenoid abduction (expiration) and maximal arytenoid collapse (inspiration). For each horse, means of measurements obtained for four breaths pre- and post-operatively were used for statistical analysis. The difference in LRQ between inspiration and expiration was lower post-operatively (median 0.039; interquartile range [IQR] 0.032-0.047) compared with pre-operatively (median 0.158; IQR 0.083-0.249; p = 0.01) confirming the left arytenoid was more stable following unilateral laser VeC. The degree of improvement was significantly greater for grade D horses compared with grade C horses (p = 0.04). The LRQ measured on maximal abduction was also lower post-operatively (median 0.467; IQR 0.444-0.506) compared with pre-operatively (median 0.578; IQR 0.554-0.655; p = 0.02) indicating the left arytenoid was less abducted following surgery. The sample size was small, no racehorses were included and post-operative assessment was conducted at a variable time after surgery. Unilateral laser VeC in grade C and D RLN-affected horses results in slightly reduced left arytenoid abduction but increased arytenoid stability.

Transfer of Motor Fascicle From the Ulnar Nerve to the Axillary Nerve by Posterior Access. New Approach.

We describe a new technique of transferring the motor branch ulnar nerve (UN) to the axillary nerve (AN) by posterior approach. Three patients with C5, C6, and C7 brachial plexus injury were operated. By supraclavicular approach, the spinal accessory was transferred to the suprascapular nerve. By posterior approach in the arm, the AN was identified within the quadrilateral space, and the UN was identified medially with intrafascicular dissection of a motor fascicle, which is lifted to 4 cm in length and transferred to AN. By medial approach, a motor branch from the median nerve is transferred to the biceps nerve. At a follow-up minimum of 10 months, the maximum abduction was 160 and the minimum 90 degrees. This technique, neurotization of the AN with fascicles of the UN, spinal accessory to suprascapular nerve, and median nerve branch to biceps nerve are indicated in C5-C7 avulsion when there is no radial nerve available. Level IV.

Biometric analysis hand parameters in young adults for prosthetic hand and ergonomic product applications.

This study aimed to evaluate the superficial anatomy, kinesiology, and functions of the hand to reveal its morphometry and apply the findings in various fields such as prosthetic hand and protective hand support product design. We examined 51 young adults (32 females, 19 males) aged between 18-30. Hand photographs were taken, and measurements were conducted using ImageJ software. Pearson correlation analysis was performed to determine the relationship between personal information and the parameters. The results of the measurements showed the average lengths of finger segments: thumb (49.5±5.5 mm), index finger (63.9±4.1 mm), middle finger (70.7±5.2 mm), ring finger (65.5±4.8 mm), and little finger (53.3±4.3 mm). Both females and males, the left index finger was measured longer than the right index finger. The right ring finger was found to be longer than the left in both sexes. Additionally, length differences between fingers in extended and maximally adducted positions were determined: thumb-index finger (56.1±6.2 mm), index-middle finger (10.7±4.1 mm), middle-ring finger (10.8±1.4 mm), and ring-little finger (25.6±2.7 mm). Other findings included the average radial natural angle (56.4°±10.5°), ulnar natural angle (23.4°±7.1°), radial deviation angle (65.2°±8.2°), ulnar deviation angle (51.2°±9.6°), and grasping/gripping angle (49.1°±5.8°). The average angles between fingers in maximum abduction positions were also measured: thumb-index finger (53.4°±6.5°), index-middle finger (17.2°±2.6°), middle-ring finger (14.3°±2.3°), and ring-little finger (32.1°±7.0°). The study examined the variability in the positioning of proximal interphalangeal joints during maximum metacarpophalangeal and proximal interphalangeal flexion, coinciding with maximum distal interphalangeal extension movements. The focal points of our observations were the asymmetrical and symmetrical arches formed by these joints. This study provides valuable hand parameters in young adults, which can be utilized in various applications such as prosthetic design, ergonomic product development, and hand-related research. The results highlight the significance of considering individual factors when assessing hand morphology and function.

Role of Ultrasound in the Diagnosis of Non-Alcoholic Fatty Liver Disease (NAFLD)

Background: The most prevalent liver illness, nonalcoholic fatty liver disease (NAFLD), is characterized by abnormal fat buildup in the hepatocytes without a substantial alcohol consumption history or secondary causes of fatty liver disease. Aim: This study aims to assess ultrasound's diagnostic utility in NAFLD. Material and Method: In the Hayatabad Medical Complex (HMC) in Peshawar, Pakistan, a cross sectional study with convenient sampling technique was conducted over six-month. This study received permission from the Institutional Research and Ethical Review Board (IREB) of HMC Hospital, and Open-Epi determined the sample size of 250 patients with a 95% confidence interval and a 5% margin of error. A certified sinologist conducted the abdominal ultrasound. The right arm was extended to its maximum abduction while the participants were positioned in the dorsal decubitus position. Using a right intercostal technique, the right liver lobe was seen, and a representative parenchymal region was identified without compromising the main vascular. The data were gathered through Questionnaire and analyzed using SPSS version 26. Results: There were 250 participants, with 55.4% men and 44.2% women. Patients between 40 and 49 accounted for 38.4% of the affected population. The most common conditions among patients with NAFLD were mild severity (49%) and abdominal discomfort (47.4%). Only (8%) of participants had liver cirrhosis before NAFLD while (91.6%) of patients lacked liver cirrhosis before NAFLD. When treating suspected NAFLD, 83.3 percent of patients preferred the Ultrasound modality initially, and more patients received a primary ultrasound diagnosis. Practical Implication: Ultrasound is the most commonly used modality because of their availability and low cost but its role in NAFLD is not fully diagnosed and evaluated. This study aims to evaluate the proper use of the Ultrasound modality in NAFLD for the benefits of patients to be diagnosed initially with Ultrasound so that it may not lead to a serious problem. Conclusion: A valuable non-invasive imaging technique for the diagnosis of non-alcoholic fatty liver disease (NAFLD) is ultrasound. Most patients first favor ultrasound, which is considered the leading imaging modality for NAFLD suspicion. The majority of NAFLD patients were middle-aged and male. Keywords: Abdominal pain, Fatigue, Liver cirrhosis, Non- Alcoholic Fatty Liver Disease, Ultrasound

Monitoring modifiable injury risk factors over an in-season mesocycle in semi-professional female field hockey players

ObjectiveThis study aimed to determine changes of modifiable injury risk factors and fatigue parameters during a mesocycle (4 months of the competitive season) in semi-professional female field hockey players (Spanish 2nd Division).MethodsFourteen female field hockey players (age: 22.6 ± 4.9 years) participated in the study over 4 months of the competitive season (September–December 2019). The players were tested each month for their: maximal isometric knee flexion, hip adduction, and abduction muscle strength; passive straight leg raise and ankle dorsiflexion range of motion (ROM); countermovement jump height; and perceptual fatigue (through a perceived well-being questionnaire).ResultsStatistical differences were reported in isometric knee flexion torque in the dominant and non-dominant limb (p = < 0.001, ηp2 = 0.629,0.786 respectively), non-dominant isometric hip abductors torque (p = 0.016, ηp2 = 0.266) and isometric hip adductors torque in dominant and non-dominant limbs (p = < 0.001, ηp2 = 0.441–546). Also, significant differences were reported in the straight leg raise test (p = < 0.001, ηp2 = 0–523, 0.556) and ankle dorsiflexion (p = 0.001, ηp2 = 0.376, 0.377) for the dominant and non-dominant limb respectively. Finally, the jump height measured showed significant differences (p = <.001, ηp2 = 0.490), while no differences were reported in perceived well-being parameters (p = 0.089–0.459).ConclusionIncrements in isometric muscle strength and fluctuations in ROM values and vertical jumping capacity are reported over an in-season mesocycle (i.e., 4 months of the competitive season). This information can be used to target recovery strategies to make them more efficient.

Varus-valgus alignment of humeral short stem in reverse total shoulder arthroplasty: does it really matter?

BackgroundThe utilization of short humeral stems in reverse total shoulder arthroplasty (RTSA) has gained attention in recent times. However, concerns regarding the risk of misalignment during implant insertion are associated with their use. MethodsEight fresh-frozen cadaveric shoulders were prepared for dissection and biomechanical testing. A bespoke humeral implant was fabricated to facilitate assessment of neutral, varus, and valgus alignments using a single stem, and 10° was established as the maximum permissible angle for misalignments. Shift in humerus position and changes in deltoid length attributable to misalignments relative to the neutral position were evaluated using a Microscribe 3DLx system. The impingement-free range of motion (IFROM), encompassing abduction, adduction, internal rotation (IR), and external rotation (ER), was gauged using a digital goniometer. The capacity for abduction was evaluated at maximal abduction angles under successive loading on the middle deltoid. A specialized traction system coupled with a force transducer was employed to measure anterior dislocation forces. ResultsRelative to the neutral alignment, valgus alignment resulted in a more distal (10.5 ± 2.4 mm) and medial (8.3 ± 2.2 mm) translation of the humeral component, whereas the varus alignment resulted in the humerus shifting more superiorly (11.2 ± 1.3 mm) and laterally (9.9 ± 0.9 mm) at 0° abduction. The valgus alignment exhibited the highest abduction angle than neutral alignment (86.2°, P<0.001). Conversely, the varus alignment demonstrated significantly higher adduction (18.4±7.4°, P<0.001), IR (68.9±15.0°, P=0.014), and ER (45.2±10.5°, P=0.002) at 0° abduction compared to the neutral alignments. Anterior dislocation forces were considerably lower (23.8N) in the varus group compared to the neutral group at 0°ER (P=0.047). Additionally, abduction capability was markedly higher in varus alignment at low deltoid loads than the neutral alignment (5N, P=0.009; 7.5N, P=0.007). ConclusionsThe varus position enhances rotational ROM but increases instability, while the valgus position does not significantly impact ROM or instability compared to the neutral position.

Clinical and Anatomical Variation During Assessment of Maximum Glottic Angle.

Quantitative measurement and analysis of glottic abduction is used to assess laryngeal function and success of interventions; however, the consistency of measurement over time has not been established. This study assesses the consistency of glottic abduction measurements across visits in healthy patients and anatomic factors impacting these measurements. Review of patients with two sequential flexible stroboscopic exams over seven months from 2019-2022. Images of maximal glottic abduction were captured and uploaded into and measured with ImageJ. Cadaver heads were used to assess the impact of visualization angles on glottic measurements with a monofilament inserted into the supraglottis of each cadaver as a point of reference. Comparisons were done with a paired T-test, T-test, or Mann-Whitney U test as appropriate. Fifty-nine patients and twenty-six cadaveric exams were included. Absolute change in maximum glottic abduction angle (MGAA) was 6.90° (95% CI [5.36°, 8.42°]; p < 0.05). There were no significant differences in change in MGAA by gender or age. Twenty percent of patients had a change of at least 25% in their MGAA between visits. Absolute differences in glottic angle between nasal side for cadaveric measurements was 4.77 ± 4.59° (p < 0.005)-2.22° less than the change in MGAA seen over time (p = 0.185). Maximal glottic abduction angles varied significantly between visits. Factors considered to be contributing to the differences include different viewing windows between examinations due to the position and angulation of the laryngoscope and changes in patient positioning, intra- and inter-rater variations in measurement, and patient effort. N/a Laryngoscope, 134:2793-2798, 2024.

The effect of vibration-hinged ankle foot orthoses on gait and spasticity in children with cerebral palsy: A randomized clinical trial design.

Hinged ankle foot orthoses (HAFO) are commonly prescribed for children with cerebral palsy (CP) to improve their ambulatory function. The aim of this study was to compare the effect of vibration-HAFO with that of the same orthosis without vibration on gait, function, and spasticity in hemiplegic CP children. Randomized Control Trial Design (a pilot study). Twenty-three children with hemiplegic CP participated in this study. The control group (n = 12) used HAFO, and the intervention group (n = 11) used vibration-HAFO for four weeks. Pre-post three-dimensional gait analysis was done. Calf muscle spasticity and function were also measured. Results showed significant differences between the two groups in the one-minute walking test (p = 0.023) and spasticity (after intervention [p = 0.022], after follow-up [p = 0.020]). Also, significant differences were detected between the two groups in the step width (p = 0.042), maximum hip abduction (p = 0.008), stance maximum dorsiflexion (p = 0.036) and mean pelvic tilt (p = 0.004) in the barefoot condition. Gait cycle time (p = 0.005), maximum hip abduction (p = 0.042), and cadence (p = 0.001) were different between groups in the braced condition. We couldn't find any significant within and between groups differences in knee kinematic parameters. The mean time of using vibration was 16.83 minutes per day. The vibration-hinged AFO is feasible, safe, and acceptable for children with hemiplegic CP to be integrated into practice. Temporospatial and clinical parameters, especially spasticity, were improved. There were slight trends toward improvement in pelvic and knee kinematics. Vibration-HAFO is of benefit to ambulatory CP children with mild and moderate spasticity. It improved the walking capacity of the children.

Influence of motor imagery training on hip abductor muscle strength and bilateral transfer effect.

Motor imagery training could be an important treatment of reduced muscle function in patients and injured athletes. In this study, we investigated the efficacy of imagery training on maximal force production in a larger muscle group (hip abductors) and potential bilateral transfer effects. Healthy participants (n = 77) took part in two experimental studies using two imagery protocols (∼30min/day, 5days/week for 2 weeks) compared either with no practice (study 1), or with isometric exercise training (study 2). Maximal hip abduction isometric torque, electromyography amplitudes (trained and untrained limbs), handgrip strength, right shoulder abduction (strength and electromyography), and imagery capability were measured before and after the intervention. Post intervention, motor imagery groups of both studies exhibited significant increase in hip abductors strength (∼8%, trained side) and improved imagery capability. Further results showed that imagery training induced bilateral transfer effects on muscle strength and electromyography amplitude of hip abductors. Motor imagery training was effective in creating functional improvements in limb muscles of trained and untrained sides.

Quantitative Evaluation of Vocal Bowing Following Bilateral Thyroplasty in Age-Related Vocal Atrophy.

Age-related vocal atrophy (ARVA) is associated with vocal fold bowing, persistent glottal gap during phonation, and dysphonia. Bilateral medialization thyroplasty is sometimes performed in patients with ARVA to improve vocal fold closure and voice. We set out to quantify stroboscopic changes in vocal fold bowing, glottal closure, and abduction angle following bilateral thyroplasty and determine how these changes affect voice quality among patients with ARVA. Fifteen individuals with ARVA who underwent bilateral medialization thyroplasty were included in this study. Two independent investigators calculated bowing index (BI), normalized glottal gap area (NGGA), and maximum abduction angle from laryngostroboscopic exams using ImageJ™. Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V) and patient-reported measures were collected before and after thyroplasty. Thyroplasty resulted in a 10-point improvement in overall CAPE-V (Mean dif -10; 95% CI -17, -3.3, p < 0.01) and VHI-10 (mean dif -3.8; 95% CI -9.8, 2.3, p = 0.19, n = 8). NGGA and BI significantly decreased following surgery (mean dif -78; 95% CI -155, -1.5, p = 0.05; and mean dif -2.1; 95% CI -2.4, -0.84, p < 0.01, respectively). BI correlated with CAPE-V scores (r = 0.66, 95% CI 0.22, 0.87, p < 0.01). When considering the normalized combined contributions of both NGGA and BI, there was a stronger correlation in CAPE-V scores (r = 0.87, 95% CI 0.50, 0.97, p < 0.01) compared with either measure alone. Thyroplasty resulted in a decrease in vocal fold bowing, glottal gap area, and CAPE-V scores in patients with ARVA. Correction of vocal bowing and glottal gap, following bilateral thyroplasty, improved voice measures following surgery. Quantitative evaluation of vocal fold morphology may be valuable when assessing the severity and treatment-response in patients with ARVA following bilateral thyroplasty. Laryngoscope, 134:835-841, 2024.

Load-induced increase in muscle activity during 30° abduction in patients with rotator cuff tears and control subjects

BackgroundRotator cuff muscles stabilise the glenohumeral joint and contribute to the initial abduction phase with other shoulder muscles. This study aimed to determine if the load-induced increase in shoulder muscle activity during a 30° abduction test is influenced by asymptomatic or symptomatic rotator cuff pathologies.Materials and MethodsTwenty-five patients with unilateral rotator cuff tears (age, 64.3 ± 10.2 years), 25 older control subjects (55.4 ± 8.2 years) and 25 younger control subjects (26.1 ± 2.3 years) participated in this study. Participants performed a bilateral 30° arm abduction and adduction movement in the scapular plane with handheld weights (0–4 kg). Activity of the deltoid, infraspinatus, biceps brachii, pectoralis major, latissimus dorsi and upper trapezius muscles was analysed at maximum abduction angle after normalisation to maximum voluntary contraction. Shoulders were classified into rotator cuff tendinopathy, asymptomatic and symptomatic rotator cuff tears, and healthy based on magnetic resonance images. A linear mixed model (loads, shoulder types) with random effects (shoulder identification) was applied to the log-transformed muscle activities.ResultsMuscle activity increased with increasing load in all muscles and shoulder types (P < 0.001), and 1-kg increments in additional weights were significant (P < 0.001). Significant effects of rotator cuff pathologies were found for all muscles analysed (P < 0.05). In all muscles, activity was at least 20% higher in symptomatic rotator cuff tears than in healthy shoulders (P < 0.001). Symptomatic rotator cuff tears showed 20–32% higher posterior deltoid (P < 0.05) and 19–25% higher pectoralis major (P < 0.01) activity when compared with asymptomatic tears.ConclusionsRotator cuff pathologies are associated with greater relative activity of shoulder muscles, even with low levels of additional load. Therefore, the inclusion of loaded shoulder tests in the diagnosis and rehabilitation of rotator cuff pathologies can provide important insight into the functional status of shoulders and can be used to guide treatment decisions.Level of evidence: Level 2.Trial registration: Ethical approval was obtained from the regional ethics committee (Ethics Committee Northwest Switzerland EKNZ 2021-00182), and the study was registered at clinicaltrials.gov on 29 March 2021 (trial registration number NCT04819724, https://clinicaltrials.gov/ct2/show/NCT04819724).