Impact of professional dance training on characteristics of postural sway.

The stability of human upright posture determines the range and dynamics of movements performed. Consequently, the repertoire and quality of the movements performed by a dancer are mainly determined by the efficiency of postural control. This is of particular importance in professional dance training that should focus on shaping optimal movement­posture interaction. To get a deeper insight into this problem, the impact of the training on postural sway characteristics during quiet stance was analyzed in 16 female students in the seventh grade of a ballet school and compared with the size­ and age­matched group of secondary school students. Center of pressure trajectories were recorded for 25.6 s while standing quiet with eyes open (EO) and then with eyes closed (EC). The assessment of postural control was based on novel normalized sway parameters including sway vector (SV), sway anteroposterior (AP) and mediolateral (ML) directional indices (DIAP and DIML), and sway ratios (SRAP and SRML). The results document a significant contribution of vision to postural stability control in ballet students, which seems to compensate for training­related changes in joint mobility and altered activity ranges of the legs' muscles. In the control group standing with EC, SV amplitude increased only by 18% whereas in the ballet students tested in the same conditions, the increase exceeded 72%. Under full control of standing posture (EO test), the training­related increase of leg muscle forces allows dancers to maintain balance with lesser effort as documented here by 21% reduced SRAP. Additionally, the dancers while tested with their EC exhibited a 12% increase in the anteroposterior sway with a concomitant reduction of the mediolateral sway. The resulting changes in the postural control asymmetry were documented by both DIAP/DIML and SV azimuth. In conclusion, our novel analysis of postural sway seems a useful tool in monitoring the effects of training as well as the proper course of postural control development in children and adolescents.

Preventing Surgeon Work-Related Musculoskeletal Disorders: A Pilot Study of the Comprehensive Operating Room Ergonomics (CORE) Program.

IMPORTANCE: Work-related musculoskeletal disorders (WMSDs) among surgeons are markedly increasing. Several proposed interventions to reduce WMSDs among surgeons have been studied, but few follow an occupational therapy-oriented approach addressing biomechanical, psychophysical, and psychosocial risk factors. OBJECTIVE: To design, implement, and assess the potential of the Comprehensive Operating Room Ergonomics (CORE) program for surgeons, a holistic evidence-based ergonomics and wellness intervention grounded in occupational therapy principles. DESIGN: Mixed-methods pilot study with the quantitative strand embedded in the qualitative strand. SETTING: University-affiliated hospital. PARTICIPANTS: Six laparoscopic surgeons. OUTCOMES AND MEASURES: CORE program outcomes were assessed using qualitative and quantitative data to indicate changes in posture, physical discomfort, sense of wellness, and operating room (OR) ergonomic performance. The Rapid Upper Limb Assessment (RULA) was used to quantify surgeons' WMSD risk level before and after intervention. RESULTS: There were 12 baseline observations (two for each participant), and two or three post-CORE implementation observations. A statistically significant difference, F(1, 6) = 8.57, p = .03, was found between pre- and post-occupational therapy intervention RULA scores. Thematic analysis of surgeon feedback, which was overwhelmingly positive, identified five themes: postural alignment, areas of commonly reported physical pain or discomfort, setup of the OR environment, surgical ergonomics training, and ergonomics in everyday life. CONCLUSIONS AND RELEVANCE: The CORE program effectively decreased ergonomic risk factors to optimize surgeons' occupational performance in the OR. This study demonstrates a potential solution to how occupational therapists can holistically support surgeons and health care providers who are at risk for WMSDs. Plain-Language Summary: By 2025, a surgeon shortage is expected, partly because of the increase in surgeons' work-related musculoskeletal disorders, which affect their health and job continuity. This pilot study shows that the Comprehensive Operating Room Ergonomics program effectively addresses these problems. The study also serves as a framework for occupational therapy professionals to work with health care providers on ergonomics, benefiting population health. Results suggest that this approach could enhance surgeons' work conditions, supporting the American Occupational Therapy Association's Vision 2025 to improve health and quality of life.

[Test-retest reliability of subjective visual vertical from different head-tilt angles in young healthy adults].

Objective:To establish the normal values of subjective visual vertical （SVV） in different head deflection angles and analyze its test and retest reliability, in order to provide a reference for the clinical application of SVV in the evaluation of vestibular disorders. Methods:Thirty-one healthy young people were selected to wear VR glasses, and the SVV data were tested in five different head-tilt, namely, 0° in the upright head position, 45°in the left head position, 45° in the right head position, 90° in the left head position, and 90° in the right head position, and were re-tested 2 weeks later. Results:①The mean values of SVV at 5 different head-tilt angles of 0°, left 45°, right 45°, left 90°, and right 90° were -0.07±1.71, 4.30±5.39, -6.51±5.58, -3.76±7.42, and 0.40±8.02, respectively, The 95% confidence limits of SVV at 0°, left 45°, right 45°, left 90°, right 90°, and right 90° were （-3.42, 3.28）, （-6.26, 14.86）, （-17.45, 4.43）, （-18.30, 10.78）, and（-15.32, 16.12）, respectively; ②The absolute values of SVV at 4 different head-tilt angles of left 45°, right 45°, left 90°, and right 90° were 5.62±3.96, 6.90±5.07, 6.82±4.70 and 6.48±4.68, respectively. The 95% confidence limits of SVV at left 45°, right 45°, left 90°, right 90°, and right 90° were（0，12.11）,（0，15.21）,（0，14.53）and（0，14.16）, respectively. The asymmetry ratio is 10% for the absolute value of the 45 ° deviation and 3% for the absolute value of the 90° deviation; ③Intra-class correlation coefficients（ICC） for 0°, left 45°, right 45°, left 90°, right 90°were 0.757, 0.673, 0.674, 0.815, and 0.856, respectively. Conclusion:SVV has good retest reliability and high stability, and the SVV normal value data of different head deviation angles established in the present study can be used as a reference for the diagnosis and evaluation of vestibular disorders.

[Analysis of the difference of therapeutic effect and predictive factors between postural and non-postural OSA after modified uvulopalatopharyngoplasty].

Objective:To analyze the factors influencing the outcome of uvulopalatopharyngoplasty in positional obstructive sleep apnea（POSA） and non-positional OSA（NPOSA） patients, and to explore the differences between the two groups. Methods:The data of 101 patients with obstructive sleep apnea who received treatment from November 2020 to November 2023 were retrospectively analyzed. Among them, 45 positional patients（POSA group） and 56 non-positional patients（NPOSA group）, who underwent overnight polysomnography were included. The upper airway（UA） anatomy was evaluated by three-dimensional computer tomography（3D-CT）. All patients received revised uvulopalatopharyngoplasty with uvula preservation and were followed using polysomnography for at least three months postoperatively. Results:The overall effective rate was 55.45%. The surgical success rate in POSA undergoing UPPP was higher than NPOSA（POSA 30/45, 66.7% versus NPOSA 26/56, 46.4%, P=0.042）. The H-UPPP effect of POSA was negatively correlated with the minimum lateral airway of the Velopharyngeal airway（r=-0.505, P<0.001）, the minimum lateral airway of the glossopharyngeal airway（r=-0.474, P=0.001） and the minimum cross-sectional area（r=-0.394, P=0.007）. Logistic analysis showed that minimal lateral airway of the glossopharynxgeum（mLAT）（OR 0.873; 95%CI 0.798-0.955, P=0.003） was a significant predictor for surgical outcomes among POSA patients. In NPOSA, age（OR 0.936; 95%CI 0.879-0.998, P=0.042） was a significant predictor for surgical outcomes. Conclusion:The effect of H-UPPP was higher in POSA than in NPOSA. The width of glossopharyngeal mLAT was an important predictor of POSA efficacy. Age was a predictor of NPOSA efficacy.

A coactivation strategy in anticipatory postural adjustments during voluntary unilateral arm movement while standing in individuals with bilateral spastic cerebral palsy.

Individuals with bilateral spastic cerebral palsy (BSCP) reportedly has problems with anticipatory postural adjustments (APAs) while standing. However, the use of coactivation strategy in APAs in individuals with BSCP has conflicting evidence. Hence, this study aimed to investigate postural muscle activities in BSCP during unilateral arm flexion task in which postural perturbations occur in the sagittal, frontal, and horizontal planes. We included 10 individuals with BSCP with level II on the Gross Motor Function Classification System (BSCP group) and 10 individuals without disability (control group). The participants stood on a force platform and rapidly flexed a shoulder from 0° to 90° at their own timing. Surface electromyograms were recorded from the rectus femoris, medial hamstring, tibialis anterior, and medial gastrocnemius. The control group showed a mixture of anticipatory activation and inhibition of postural muscles, whereas the BSCP group predominantly exhibited anticipatory activation with slight anticipatory inhibition. Compared with the control group, the BSCP group tended to activate the ipsilateral and contralateral postural muscles and the agonist-antagonist muscle pairs. The BSCP group had a larger disturbance in postural equilibrium, quantified by the peak displacement of center of pressure during the unilateral arm flexion, than those without disability. Individuals with BSCP may use coactivation strategy, mainly the anticipatory activation of postural muscle activity, during a task that requires a selective postural muscle activity to maintain stable posture.

Prevalence of Forward head posture among car and bike drivers and its relation with neck and cardiopulmonary health parameters- a cross-sectional study.

OBJECTIVES: This study aimed to evaluate and compare the prevalence of Forward Head Posture (FHP) in car and bike drivers, and its potential correlation with neck and cardiopulmonary parameters. METHODS: This cross-sectional study involved 400 participants from urban and suburban areas around Lucknow, Uttar Pradesh, India, including 200 car drivers and 200 bike drivers aged 18-65 years with a minimum five-year driving history. Neck health was assessed using measurements such as cervical range of motion and Neck Disability Index (NDI), cardiopulmonary parameters were evaluated through resting heart rate, blood pressure, and pulmonary function tests using the spirometry test, and FHP was assessed using Surgimap application. Statistical analysis was performed using IBM SPSS Statistics software (version 26.0) and included descriptive statistics, hypothesis testing, Chi-square or Fisher's exact test for binary data, and correlation analyses. RESULTS: The result show that difference in the mean FHP between car and bike drivers was statistically significant (p = 0.0001), indicating a higher prevalence of FHP among car drivers than among bike drivers. Correlation analyses revealed significant associations between FHP and neck health metrics, especially cervical flexion (r = 0.71, p<0.05), (r = 0.78, p<0.05) and left-side rotation (r = 0.56, p<0.05), (r = 0.61, p<0.05) in car and bike drivers. Among the cardiopulmonary parameters, significant correlations with FHP were observed in resting heart rate (r = 0.33, p<0.05), (r = 0.42, p<0.05), spirometry results FVC (r = 0.29, p<0.05), FEV1 (r = 0.22, p<0.05), and FVC (r = 0.31, p<0.05) for car and bike drivers. CONCLUSION: We observed a higher incidence of FHP in car drivers, indicating that a prolonged static posture may lead to greater postural deviation than dynamic movement during biking. This association suggests that FHP could have wide-reaching implications for systemic health, beyond musculoskeletal issues. These findings have the potential to influence preventative strategies and interventions aimed at improving the overall health outcomes for drivers.

Delayed reinforcement learning converges to intermittent control for human quiet stance.

The neural control of human quiet stance remains controversial, with classic views suggesting a limited role of the brain and recent findings conversely indicating direct cortical control of muscles during upright posture. Conceptual neural feedback control models have been proposed and tested against experimental evidence. The most renowned model is the continuous impedance control model. However, when time delays are included in this model to simulate neural transmission, the continuous controller becomes unstable. Another model, the intermittent control model, assumes that the central nervous system (CNS) activates muscles intermittently, and not continuously, to counteract gravitational torque. In this study, a delayed reinforcement learning algorithm was developed to seek optimal control policy to balance a one-segment inverted pendulum model representing the human body. According to this approach, there was no a-priori strategy imposed on the controller but rather the optimal strategy emerged from the reward-based learning. The simulation results indicated that the optimal neural controller exhibits intermittent, and not continuous, characteristics, in agreement with the possibility that the CNS intermittently provides neural feedback torque to maintain an upright posture.

A Wearable Personalised Sonification and Biofeedback Device to Enhance Movement Awareness.

Movement sonification has emerged as a promising approach for rehabilitation and motion control. Despite significant advancements in sensor technologies, challenges remain in developing cost-effective, user-friendly, and reliable systems for gait detection and sonification. This study introduces a novel wearable personalised sonification and biofeedback device to enhance movement awareness for individuals with irregular gait and posture. Through the integration of inertial measurement units (IMUs), MATLAB, and sophisticated audio feedback mechanisms, the device offers real-time, intuitive cues to facilitate gait correction and improve functional mobility. Utilising a single wearable sensor attached to the L4 vertebrae, the system captures kinematic parameters to generate auditory feedback through discrete and continuous tones corresponding to heel strike events and sagittal plane rotations. A preliminary test that involved 20 participants under various audio feedback conditions was conducted to assess the system's accuracy, reliability, and user synchronisation. The results indicate a promising improvement in movement awareness facilitated by auditory cues. This suggests a potential for enhancing gait and balance, particularly beneficial for individuals with compromised gait or those undergoing a rehabilitation process. This paper details the development process, experimental setup, and initial findings, discussing the integration challenges and future research directions. It also presents a novel approach to providing real-time feedback to participants about their balance, potentially enabling them to make immediate adjustments to their posture and movement. Future research should evaluate this method in varied real-world settings and populations, including the elderly and individuals with Parkinson's disease.

Smart Sleep Monitoring: Sparse Sensor-Based Spatiotemporal CNN for Sleep Posture Detection.

Sleep quality is heavily influenced by sleep posture, with research indicating that a supine posture can worsen obstructive sleep apnea (OSA) while lateral postures promote better sleep. For patients confined to beds, regular changes in posture are crucial to prevent the development of ulcers and bedsores. This study presents a novel sparse sensor-based spatiotemporal convolutional neural network (S3CNN) for detecting sleep posture. This S3CNN holistically incorporates a pair of spatial convolution neural networks to capture cardiorespiratory activity maps and a pair of temporal convolution neural networks to capture the heart rate and respiratory rate. Sleep data were collected in actual sleep conditions from 22 subjects using a sparse sensor array. The S3CNN was then trained to capture the spatial pressure distribution from the cardiorespiratory activity and temporal cardiopulmonary variability from the heart and respiratory data. Its performance was evaluated using three rounds of 10 fold cross-validation on the 8583 data samples collected from the subjects. The results yielded 91.96% recall, 92.65% precision, and 93.02% accuracy, which are comparable to the state-of-the-art methods that use significantly more sensors for marginally enhanced accuracy. Hence, the proposed S3CNN shows promise for sleep posture monitoring using sparse sensors, demonstrating potential for a more cost-effective approach.

Deciphering Optimal Radar Ensemble for Advancing Sleep Posture Prediction through Multiview Convolutional Neural Network (MVCNN) Approach Using Spatial Radio Echo Map (SREM).

Assessing sleep posture, a critical component in sleep tests, is crucial for understanding an individual's sleep quality and identifying potential sleep disorders. However, monitoring sleep posture has traditionally posed significant challenges due to factors such as low light conditions and obstructions like blankets. The use of radar technolsogy could be a potential solution. The objective of this study is to identify the optimal quantity and placement of radar sensors to achieve accurate sleep posture estimation. We invited 70 participants to assume nine different sleep postures under blankets of varying thicknesses. This was conducted in a setting equipped with a baseline of eight radars-three positioned at the headboard and five along the side. We proposed a novel technique for generating radar maps, Spatial Radio Echo Map (SREM), designed specifically for data fusion across multiple radars. Sleep posture estimation was conducted using a Multiview Convolutional Neural Network (MVCNN), which serves as the overarching framework for the comparative evaluation of various deep feature extractors, including ResNet-50, EfficientNet-50, DenseNet-121, PHResNet-50, Attention-50, and Swin Transformer. Among these, DenseNet-121 achieved the highest accuracy, scoring 0.534 and 0.804 for nine-class coarse- and four-class fine-grained classification, respectively. This led to further analysis on the optimal ensemble of radars. For the radars positioned at the head, a single left-located radar proved both essential and sufficient, achieving an accuracy of 0.809. When only one central head radar was used, omitting the central side radar and retaining only the three upper-body radars resulted in accuracies of 0.779 and 0.753, respectively. This study established the foundation for determining the optimal sensor configuration in this application, while also exploring the trade-offs between accuracy and the use of fewer sensors.

Different mechanisms of contextual inference govern associatively learned and sensory-evoked postural responses.

Human standing balance relies on the continuous monitoring and integration of sensory signals to infer our body's motion and orientation within the environment. However, when sensory information is no longer contextually relevant to balancing the body (e.g., when sensory and motor signals are incongruent), sensory-evoked balance responses are rapidly suppressed, much earlier than any conscious perception of changes in balance control. Here, we used a robotic balance simulator to assess whether associatively learned postural responses are similarly modulated by sensorimotor incongruence and contextual relevance to postural control. Twenty-nine participants in three groups were classically conditioned to generate postural responses to whole-body perturbations when presented with an initially neutral sound cue. During catch and extinction trials, participants received only the auditory stimulus but in different sensorimotor states corresponding to their group: 1) during normal active balance, 2) while immobilized, and 3) throughout periods where the computer subtly removed active control over balance. In the balancing and immobilized states, conditioned responses were either evoked or suppressed, respectively, according to the (in)ability to control movement. Following the immobilized state, conditioned responses were renewed when balance was restored, indicating that conditioning was retained but only expressed when contextually relevant. In contrast, conditioned responses persisted in the computer-controlled state even though there was no causal relationship between motor and sensory signals. These findings suggest that mechanisms responsible for sensory-evoked and conditioned postural responses do not share a single, central contextual inference and assessment of their relevance to postural control, and may instead operate in parallel.

Individuals with asymptomatic hallux valgus exhibit altered foot kinematics during gait regardless of their foot posture.

BACKGROUND: A flatfoot has been believed to be closely associated with the development of hallux valgus; however, the association is still controversial. Abnormal foot kinematics has been identified as a possible risk factor for the development of hallux valgus, but it remains unclear whether foot posture contributes to abnormal foot kinematics. This is the first study to investigate the differences in foot kinematics during gait between individuals with and without hallux valgus, while controlling for foot posture. METHODS: Twenty-five females with hallux valgus and 25 healthy females aged 18 to 22 were recruited. Foot posture was measured using normalized navicular height truncated and the leg-heel angle. Foot kinematic and kinetic data during gait were recorded by a three-dimensional motion capture system. To investigate the characteristics of foot kinematics in individuals with hallux valgus while controlling for foot posture, we used a propensity score matching method. The matching was obtained by using the 1:1 nearest-neighbor procedure and a caliper width of 0.2. FINDINGS: Twelve pairs were matched. Individuals with hallux valgus had significantly increased midfoot dorsiflexion from 56% to 80% during stance phase, rearfoot eversion from 53% to 71%, and forefoot abduction from 5% to 29% compared with control. INTERPRETATION: Individuals with hallux valgus have a flexible foot that cannot suppress the dynamic deformation of the rearfoot and midfoot during gait. To suppress the development of hallux valgus, interventions that aim to prevent dynamic deformations of the rearfoot and midfoot during gait may be necessary, regardless of their static foot posture.

Designing and Analyzing In-Place Motor Tasks in Virtual Reality With Goal Functions.

Goal functions make virtual goal-oriented motor tasks easier to analyze and manipulate by explicitly linking movement to outcome. However, they have only been used to study constrained (e.g., planar) upper limb movements. We present a design framework for integrating goal functions with unconstrained postural and upper limb movements in a virtual reality (VR) device. VR tasks designed with the framework can mimic unconstrained natural motions and thus train a range of functional movements yet remain analytically tractable. We created three in-place VR motor tasks: a bow-and-arrow, a reach-and-strike, and a punching bag task. Each task was adjusted to subject-specific workspace limits and anthropometrics. We studied the effects of 3 days of practice and 3 reach/lean distances on task performance in 12 healthy adults. Subjects performed all tasks on day 1 with moderate proficiency and improved with practice at all reach/lean distances. Task-specific results showed that performance decreased and movement variability increased near the edge of the reaching workspace; viewing angles and the imperfect depth cues in VR likely led to biases in performance and practice could attenuate the former effect; in reach-and-strike, subjects learned movement patterns similar to those seen in a real-world striking sport. These results show that our framework can deliver tasks useful for analyzing and training motor performance and can guide future in-place motor training. Post-hoc, we demonstrated the feasibility of generalizable methods that adjust required movement speeds and task difficulty for impaired populations.

[Synchronous analysis of ankle coronal plane tilt angle and peripheral associated muscle load in semi-squat landing of paratroopers].

Objective: To investigate the relationship between ankle stability and associated muscle load around the ankle and the effect of a parachute ankle brace (PAB) on ankle inversion and associated muscle load around the ankle during landing through the simulated paratrooper semi-squat landing field experiment. Methods: In August 2021, 37 male paratroopers were randomly selected as the study objects to perform parachute landing training in the semi-squat posture on the 1.5 m and 2.0 m jump platforms with or without PAB, respectively. The coronal plane tilt angle of ankle joint and the percentage of maximum voluntary contraction (MVC%) of associated muscles around ankle joint during the process were measured and correlation analysis was conducted. And the effect of wearing PAB on the coronal plane tilt angle of ankle joint and the associated muscles around the ankle joint was analyzed. Results: During the semi-squat landing, the MVC% of the tibialis anterior muscle, lateral gastrocnemius muscle and peroneus longus muscle were positively correlated with the ankle coronal plane tilt angle in paratroopers wearing and without wearing PAB, and the correlations were statistically significant (P<0.05). At the same height, compared with those without PAB, the coronal plane tilt angle of the ankle joint decreased during semi-squat landing in paratroopers PAB, and the differences were statistically significant (P<0.05). At the landing moment of the same height, compared with those without PAB, the MVC% of lateral gastrocnemius muscle decreased and the MVC% of peroneus longus muscle increased in paratroopers wearing PAB, and the differences were statistically significant (P<0.05). After the landing moment until the standing stage (100-200 ms) at 1.5 m height, the MVC% of the tibialis anterior muscle decreased in paratroopers wearing PAB compared with those without PAB, and the differences were statistically significant (P<0.05). In the post-standing stage (200 ms) at 2.0 m height, the MVC% of the tibialis anterior muscle decreased in paratroopers wearing PAB compared with those without PAB, and the difference was statistically significant (P<0.05) . Conclusion: Wearing PAB can reduce the ankle coronal plane tilt angle, improve ankle stability, reduce the muscle load of the lateral gastrocnemius muscle at the moment of landing, and reduce the load of the tibialis anterior muscle after landing, but increase the peroneus longus muscle load at the moment of landing.

How the brain can be trained to achieve an intermittent control strategy for stabilizing quiet stance by means of reinforcement learning.

The stabilization of human quiet stance is achieved by a combination of the intrinsic elastic properties of ankle muscles and an active closed-loop activation of the ankle muscles, driven by the delayed feedback of the ongoing sway angle and the corresponding angular velocity in a way of a delayed proportional (P) and derivative (D) feedback controller. It has been shown that the active component of the stabilization process is likely to operate in an intermittent manner rather than as a continuous controller: the switching policy is defined in the phase-plane, which is divided in dangerous and safe regions, separated by appropriate switching boundaries. When the state enters a dangerous region, the delayed PD control is activated, and it is switched off when it enters a safe region, leaving the system to evolve freely. In comparison with continuous feedback control, the intermittent mechanism is more robust and capable to better reproduce postural sway patterns in healthy people. However, the superior performance of the intermittent control paradigm as well as its biological plausibility, suggested by experimental evidence of the intermittent activation of the ankle muscles, leaves open the quest of a feasible learning process, by which the brain can identify the appropriate state-dependent switching policy and tune accordingly the P and D parameters. In this work, it is shown how such a goal can be achieved with a reinforcement motor learning paradigm, building upon the evidence that, in general, the basal ganglia are known to play a central role in reinforcement learning for action selection and, in particular, were found to be specifically involved in postural stabilization.

Cumulative Effects of Concurrent Inspiratory Muscle Training and Postural Correction Bands on Older Individuals Community Dwellers: A Randomized Study.

PURPOSE: Posture correction bands (PCBs) have been proposed as aids to help chest expansion and to enhance respiratory function. However, the impact of PCBs on community-based older individuals engaged in inspiratory muscle training (IMT) at home remains unclear. MATERIALS AND METHODS: Community-based individuals aged 65 years and older were divided into the PCB group, wearing PCBs, and the NPCB group, not wearing PCBs. The IMT regimen lasted 8 weeks, with sessions 5 times a week, including 4 sets per day and 15 repetitions per set. Training intensity was set at 50% of the maximum inspiratory pressure of each subject. To assess the effects of IMT, respiratory function, 6-minute walk test, and grip strength were measured before, during, and after the training period. Data were analyzed using repeated-measures analysis of variance, with post-hoc evaluation employing Bonferroni correction. RESULTS: A total of 40 subjects were evenly divided into the PCB group and the NPCB group, with 20 subjects in each group. No significant difference was observed in respiratory muscle strength based on PCB use. However, during the initial 4 weeks, the PCB group exhibited a trend towards an increase in respiratory muscle strength compared to the NPCB group; this trend, however, did not prove to be statistically significant by the end of the 8-week period. Performance on the 6-minute walk test significantly improved in both groups. CONCLUSION: The PCB group exhibited a tendency for increase in respiratory muscle strength in the first 4 weeks; however, ultimately there was no significant difference compared to the NPCB group. CLINICAL TRIAL REGISTRATION: This study was registered with the Clinical Research Information Service, part of the World Health Organization's International Clinical Trials Registry Platform (Clinical Research Information Service No. KCT0008075).

Postural control during the back squat at different load intensities in powerlifters and weightlifters.

BACKGROUND: The movement of the barbell has been detected as success factor for the snatch and the clean and jerk events. As the barbell's movement has been shown to be related to the athlete's body movement, we hypothesized that the latter could be a success factor also for the back squat (BS) event. Hence, this study aimed to investigate postural control during the execution of the BS at different load intensities in powerlifters and weightlifters. METHODS: Seventeen powerlifters and weightlifters were enrolled and the one-repetition maximum (1-RM) of the BS of each participant was measured. Afterwards, the assessment of postural control during the execution of the BS at different load intensities (i.e. 60%, 70%, 80%, 90%, 100%) of the 1-RM of each participant was carried out through a posturographic platform to measure the displacement of the centre of pressure (CoP). The following parameters were considered: sway path length (SPL), sway ellipse surface (SES), length/surface (LFS ratio), sway mean speed (SMS), CoP coordinates along X and Y planes. RESULTS: We found a significant increase in SPL and LFS ratio, and a significant decrease in SMS as the load intensity increased. In detail, we detected a significant difference in: (a) SPL between the BS at 60% and 80%, 60% and 90%, 60% and 100%; between the BS at 70% and 90%, 70% and 100%; between the BS at 80% and 100%; and between the BS at 90% and 100%; (b) SMS between the BS at 60% and 80%, 60% and 90%; (c) LFS ratio between the BS at 60% and 90%, 60% and 100%. CONCLUSIONS: These results suggest that powerlifters and weightlifters adopt different postural control strategies depending on the load intensity when performing the BS. Our findings showed that higher effort could affect postural control during the BS. Thus, postural control could be considered a success factor for the BS.

Change in cup orientation from supine to standing posture: a prospective cohort study of 419 total hip arthroplasties.

BACKGROUND AND PURPOSE: Arthroplasty surgeons traditionally assess cup orientation after total hip arthroplasty (THA) on supine radiographs. Contemporary hip-spine analyses provide information on standing, functional cup orientation. This study aims to (i) characterize cup orientations when supine and standing; (ii) determine orientation differences between postures; and (iii) identify factors associated with magnitude of orientation differences. METHODS: This is a 2-center, multi-surgeon, prospective, consecutive cohort study. 419 primary THAs were included (57% women; mean age: 64 years, standard deviation [SD] 11). All patients underwent supine and standing antero-posterior pelvic and lateral spinopelvic radiographs. Cup orientation and spinopelvic parameters were measured. Target cup orientation was defined as inclination/anteversion of 40°/20° ± 10°. A change in orientation (Δinclination/Δanteversion) between postures > 5° was defined as clinically significant. Variability was defined as 2 x SD. RESULTS: Inclination increased from 40° (supine) to 42° (standing) corresponding to a Δinclination of 2° (95% confidence interval [CI] 2-3). Anteversion increased from 25° (supine) to 30° (standing) corresponding to a Δanteversion of 5° (CI 5-6). When supine, 69% (CI 65-74) of THAs were within target, but only 44% (CI 39-49) were within target when standing, resulting in a further 26% (CI 21-30) being out of target when standing. From supine to standing, a clinically significant change in anteversion (> 5°) was seen in 47% (CI 42-52) of cases. Δanteversion was higher in women than in men (6°, CI 5-7 vs 5°, CI 4-5) corresponding to a difference of 1° (CI 1-2), which was dependent on tilt change, standing cup anteversion, age, and standing pelvic tilt. CONCLUSION: Cup inclination and version increase upon standing but significant variability exists due to patient factors.

Therapeutic Interventions for Prevention of Musculoskeletal Pain Among Orthopedic Surgeons.

Orthopedic surgery is a physically demanding specialty. The factors contributing to musculoskeletal injury among surgeons often stem from positioning the patient, using non-ergonomic instruments, maintaining static postures, and performing repetitive movements. This article focuses on exercise techniques intended to combat the most common problematic static postures held during procedures. Each exercise explained in this article is organized into "preop," "intraop," and "postop" components. Preop includes strengthening movements, intraop provides postural recommendations, and postop focuses on mobilization and recovery. This article aims for efficient body conditioning, targeting the muscular posterior chain and supporting elements. [Orthopedics. 2024;47(4):e214-e216.].

Thigh-worn accelerometry: a comparative study of two no-code classification methods for identifying physical activity types.

BACKGROUND: The more accurate we can assess human physical behaviour in free-living conditions the better we can understand its relationship with health and wellbeing. Thigh-worn accelerometry can be used to identify basic activity types as well as different postures with high accuracy. User-friendly software without the need for specialized programming may support the adoption of this method. This study aims to evaluate the classification accuracy of two novel no-code classification methods, namely SENS motion and ActiPASS. METHODS: A sample of 38 healthy adults (30.8 ± 9.6 years; 53% female) wore the SENS motion accelerometer (12.5 Hz; ±4 g) on their thigh during various physical activities. Participants completed standardized activities with varying intensities in the laboratory. Activities included walking, running, cycling, sitting, standing, and lying down. Subsequently, participants performed unrestricted free-living activities outside of the laboratory while being video-recorded with a chest-mounted camera. Videos were annotated using a predefined labelling scheme and annotations served as a reference for the free-living condition. Classification output from the SENS motion software and ActiPASS software was compared to reference labels. RESULTS: A total of 63.6 h of activity data were analysed. We observed a high level of agreement between the two classification algorithms and their respective references in both conditions. In the free-living condition, Cohen's kappa coefficients were 0.86 for SENS and 0.92 for ActiPASS. The mean balanced accuracy ranged from 0.81 (cycling) to 0.99 (running) for SENS and from 0.92 (walking) to 0.99 (sedentary) for ActiPASS across all activity types. CONCLUSIONS: The study shows that two available no-code classification methods can be used to accurately identify basic physical activity types and postures. Our results highlight the accuracy of both methods based on relatively low sampling frequency data. The classification methods showed differences in performance, with lower sensitivity observed in free-living cycling (SENS) and slow treadmill walking (ActiPASS). Both methods use different sets of activity classes with varying definitions, which may explain the observed differences. Our results support the use of the SENS motion system and both no-code classification methods.