Physiological and clinical effects of trunk inclination adjustment in patients with respiratory failure: a scoping review and narrative synthesis.

BACKGROUND: Adjusting trunk inclination from a semi-recumbent position to a supine-flat position or vice versa in patients with respiratory failure significantly affects numerous aspects of respiratory physiology including respiratory mechanics, oxygenation, end-expiratory lung volume, and ventilatory efficiency. Despite these observed effects, the current clinical evidence regarding this positioning manoeuvre is limited. This study undertakes a scoping review of patients with respiratory failure undergoing mechanical ventilation to assess the effect of trunk inclination on physiological lung parameters. METHODS: The PubMed, Cochrane, and Scopus databases were systematically searched from 2003 to 2023. INTERVENTIONS: Changes in trunk inclination. MEASUREMENTS: Four domains were evaluated in this study: 1) respiratory mechanics, 2) ventilation distribution, 3) oxygenation, and 4) ventilatory efficiency. RESULTS: After searching the three databases and removing duplicates, 220 studies were screened. Of these, 37 were assessed in detail, and 13 were included in the final analysis, comprising 274 patients. All selected studies were experimental, and assessed respiratory mechanics, ventilation distribution, oxygenation, and ventilatory efficiency, primarily within 60 min post postural change. CONCLUSION: In patients with acute respiratory failure, transitioning from a supine to a semi-recumbent position leads to decreased respiratory system compliance and increased airway driving pressure. Additionally, C-ARDS patients experienced an improvement in ventilatory efficiency, which resulted in lower PaCO2 levels. Improvements in oxygenation were observed in a few patients and only in those who exhibited an increase in EELV upon moving to a semi-recumbent position. Therefore, the trunk inclination angle must be accurately reported in patients with respiratory failure under mechanical ventilation.

Changes of in vivo electrical conductivity in the brain and torso related to age, fat fraction and sex using MRI.

This work was inspired by the observation that a majority of MR-electrical properties tomography studies are based on direct comparisons with ex vivo measurements carried out on post-mortem samples in the 90's. As a result, the in vivo conductivity values obtained from MRI in the megahertz range in different types of tissues (brain, liver, tumors, muscles, etc.) found in the literature may not correspond to their ex vivo equivalent, which still serves as a reference for electromagnetic modelling. This study aims to pave the way for improving current databases since the definition of personalized electromagnetic models (e.g. for Specific Absorption Rate estimation) would benefit from better estimation. Seventeen healthy volunteers underwent MRI of both brain and thorax/abdomen using a three-dimensional ultrashort echo-time (UTE) sequence. We estimated conductivity (S/m) in several classes of macroscopic tissue using a customized reconstruction method from complex UTE images, and give general statistics for each of these regions (mean-median-standard deviation). These values are used to find possible correlations with biological parameters such as age, sex, body mass index and/or fat volume fraction, using linear regression analysis. In short, the collected in vivo values show significant deviations from the ex vivo values in conventional databases, and we show significant relationships with the latter parameters in certain organs for the first time, e.g. a decrease in brain conductivity with age.

Using Resistance-Band Tests to Evaluate Trunk Muscle Strength in Chronic Low Back Pain: A Test-Retest Reliability Study.

Exercise is a front-line intervention to increase functional capacity and reduce pain and disability in people with low strength levels or disorders. However, there is a lack of validated field-based tests to check the initial status and, more importantly, to control the process and make tailored adjustments in load, intensity, and recovery. We aimed to determine the test-retest reliability of a submaximal, resistance-band test to evaluate the strength of the trunk stability muscles using a portable force sensor in middle-aged adults (48 ± 13 years) with medically diagnosed chronic low back pain and healthy peers (n = 35). Participants completed two submaximal progressive tests of two resistance-band exercises (unilateral row and Pallof press), consisting of 5 s maintained contraction, progressively increasing the load. The test stopped when deviation from the initial position by compensation movements occurred. Trunk muscle strength (CORE muscles) was monitored in real time using a portable force sensor (strain gauge). Results revealed that both tests were highly reliable (intra-class correlation [ICC] > 0.901) and presented low errors and coefficients of variation (CV) in both groups. In particular, people with low back pain had errors of 14-19 N (CV = 9-12%) in the unilateral row test and 13-19 N (CV = 8-12%) in the Pallof press. No discomfort or pain was reported during or after the tests. These two easy-to-use and technology-based tests result in a reliable and objective screening tool to evaluate the strength and trunk stability in middle-aged adults with chronic low back pain, considering an error of measurement < 20 N. This contribution may have an impact on improving the individualization and control of rehabilitation or physical training in people with lumbar injuries or disorders.

Understanding the flexion-relaxation phenomenon in non-specific chronic low back pain patients throught immersive virtual reality feedback approach.

The flexion-relaxation phenomenon (FRP) is frequently absent among non-specific chronic low back pain (NSCLBP) patients. However, it is unknown whether this absence is intrinsic to their pathology or merely a consequence of reduced trunk flexion. Immersive virtual reality (IVR) can create a patient avatar whose range of motion can be modulated to differ from the real movement. The present study enrolled 15 NSCLBP patients and 15 asymptomatic participants with similar characteristics to disentangle the relationship between range of motion and the FRP in NSCLBP using IVR. Trunk kinematics and lumbar muscle electromyography were assessed. The IVR environment was combined with a motion capture system to create avatars that moved like each participant. The IVR display showed a closed room and a mirror reflecting the subject's avatar with a target line to be reached by trunk flexion. The avatar's trunk movements were modulated from reality, leading the participants to flex their trunk more than their voluntary maximum trunk flexion. Under IVR conditions, NSCLBP patients significantly increased their trunk flexion angle, which was coupled with a significant improvement in the FRP. The absence of the FRP among the NSCLBP population appeared to be primarily related to reduced trunk flexion.

Acute effect of dry needling on trunk kinematics and balance of patients with non-specific low back pain.

BACKGROUND: Limited knowledge exists about the effectiveness of dry needling (DN) concerning the torso kinematics in patients with non-specific low back pain (NS-LBP). Acute effects of DN in NS-LBP patients from a functional perspective were investigated. METHODS: Sixteen NS-LBP patients and 11 healthy individuals (HG) were examined. NS-LBP patients received a single session of DN at the lumbar region. Baseline and immediate post-treatment measurements during flexion-extension and lateral bending of the trunk were conducted for the NS-LBP patients. HG were measured only at baseline to be used as a reference of NS-LBP patients' initial condition. Algometry was applied in NS-LBP patients. Centre of pressure, range of motion of the trunk and its' derivatives were obtained. FINDINGS: HG performed significantly faster, smoother and with greater mobility in the performed tasks compared to the pre intervention measurements of the NS-LBP patients. For the NS-LBP patients, significant greater angular velocity in frontal plane and significant lower jerk in the sagittal plane were demonstrated post intervention. DN alleviated pain tolerance significantly at the L5 level. Regarding the effectiveness of the DN upon spine kinematics, their derivatives were more sensitive. INTERPRETATION: It appeared that the pathological type of torso movement was acutely affected by DN. NS-LBP patients showcased smoother movement immediately after the intervention and better control as imprinted in the higher derivative of motion although range of motion did not improve. This quantitative variable may not be subjected to acute effects of DN but rather need additional time and training to be improved.

Motor alterations along the kinetic chain in amateur volleyball and handball athletes with shoulder pain: An observational comparative study.

Overhead sports overload the shoulder complex due to movement repetition and the great amount of force created during the athletic motion, which may cause adaptations in the shoulder and lead to shoulder pain. However, overhead movements include the kinetic chain, and alterations in some of the structures throughout the kinetic chain may increase stress on the shoulder complex and be associated with shoulder pain. PURPOSE: To compare kinetic chain components in overhead athletes with and without shoulder pain. METHODS: Forty-one volleyball and handball athletes (21 with and 20 without shoulder pain) were included and assessed for hip internal (IR) and external rotation (ER) range of motion (ROM), hip and trunk isometric strength, trunk endurance and neuromuscular control of the lower and upper limbs (Y balance test). RESULTS: Athletes with shoulder pain showed smaller IR ROM in both hips, lower endurance time for trunk extensors and flexors, decreased reach distance in the anterior and posteromedial direction, as well as a smaller composite score in the Y balance test (p < 0.05). CONCLUSION: Volleyball and handball athletes with shoulder pain showed changes in ROM throughout the kinetic chain in addition to lower core endurance, and decreased neuromuscular control of lower limbs.

Relationships among lateral medicine ball throw test performance, HIP and trunk muscle strength, and lower limb kinematics: A cross-sectional study.

INTRODUCTION: The lateral medicine ball throw (LMBT) test is used to evaluate the throwing action, involving the entire kinetic chain and the principle of force transfer, with association between the strength of the lower limb and trunk muscles and the lower limb kinematics. The LMBT to investigate the association between lower limb kinematics and hip and trunk muscle strength. EXPERIMENTAL: This was a cross-sectional study with 84 healthy and physically active young people. Determinations were made of the maximum isometric strengths of the hip abductor, lateral rotator, extensor, and flexor muscles, and the trunk lateral flexors and extensors. Kinematic analyses (2D) of the hip, knee, and ankle in the sagittal and frontal planes were performed during the countermovement phase of the LMBT, together with quantification of LMBT. Statistical analysis of the associations employed multiple linear regression, with α = 5%. RESULTS: There were significant associations between the LMBT and the independent variables hip extensors strength, trunk flexors strength, valgus angle, and knee flexion angle and gender. The regression model presented adjusted R2 = 0.622. CONCLUSIONS: LMBT was influenced by the trunk flexor and hip extensor muscle strengths, knee flexion kinematics, lower limb valgus in the countermovement phase, and gender.

Countermovement Jump and Momentum Generation Associations to Fastball Velocity Performance Among Division I Collegiate Pitchers.

ABSTRACT: Sakurai, M, Qiao, M, Szymanski, DJ, and Crotin, RL. Countermovement jump and momentum generation associations to fastball velocity performance among Division I collegiate pitchers. J Strength Cond Res 38(7): 1288-1294, 2024-The current study explored the relationships between countermovement jump (CMJ) profiles and baseball pitching performance. Nineteen Division I collegiate pitchers performed in-laboratory pitching and bilateral CMJs. Whole-body kinematics and ground reaction force were collected during both pitching and CMJ evaluations. Statistically significant correlations of concentric impulse and peak power in the CMJ test with fastball velocity were observed (r = 0.71 and 0.68). Concentric impulse in CMJ also showed a statistically significant correlation with linear momentum in the anterior-posterior direction during pitching (r = 0.68). Lean body mass and body mass showed statistically significant correlations with both of the 2 linear momentums during pitching (r = 0.71∼0.83), and concentric impulse in CMJ (r = 0.71 and 0.81). Pelvis and trunk pitching mechanics did not correlate with any of the CMJ variables at the statistically significant level, whereas the direction of the correlations varied (|r| < 0.45). Assessment of a baseball pitcher's CMJ should focus on concentric impulse and peak power because only these showed meaningful relationships with fastball velocity or momentum generation during pitching. An increase in lean body mass is also suggested to be able to generate more impulse and momentum. Baseball coaches, strength coaches, and clinicians are encouraged to include lower-body explosive training to enhance the force and power output capacity of baseball pitchers.

The effects of various stair-climbing exercises on functional mobility and trunk muscle activation in community-dwelling older adults: A pilot randomized controlled trial.

BACKGROUND: Stair-climbing (SC) is an essential daily life skill, and stair-climbing exercise (SCE) serves as a valuable method for promoting physical activity in older adults. This study aimed to compare the impact of SCEs with heel contact (HC) and heel off (HO) during SC on functional mobility and trunk muscle (TM) activation amplitudes in community-dwelling older adults. METHODS: In the pilot randomized controlled trial, participants were randomly allocated to either the HC group (n = 17; mean age 75.9 ± 6.3 years) or the HO group (n = 17; mean age 76.5 ± 4.6 years). The HC participants performed SCE with the heel of the ankle in contact with the ground, while the HO participants performed SCE with the heel of the ankle off the ground during SC. Both groups participated in progressive SCE for one hour per day, three days per week, over four consecutive weeks (totaling 12 sessions) at the community center. We measured timed stair-climbing (TSC), timed up and go (TUG), and electromyography (EMG) amplitudes of the TMs including rectus abdominis (RA), external oblique (EO), transverse abdominus and internal oblique abdominals (TrA-IO), and erector spinae (ES) during SC before and after the intervention. RESULTS: Both groups showed a significant improvement in TSC and TUG after the intervention (P < .01, respectively), with no significant difference between the groups. There was no significant difference in the EMG activity of the TMs between the groups after the intervention. The amplitude of TMs significantly decreased after the intervention in both groups (P < .01, respectively). CONCLUSION: Both SCE methods could improve balance and SC ability in older adults while reducing the recruitment of TMs during SC. Both SCE strategies are effective in improving functional mobility and promoting appropriate posture control during SC in older adults.

The reliability, variability and minimal detectable change of multiplanar isometric trunk strength testing using a fixed digital dynamometer.

Trunk strength plays a vital role in athletic performance, rehabilitation and general health, however, current assessment methods are expensive, non-portable or unreliable. This study aimed to investigate the within- and between-session reliability, variability, standard error of measurement and minimal detectable change (MDC) of trunk strength in the sagittal (flexion and extension) and frontal planes (left and right lateral flexion) using a fixed digital dynamometer. Eighteen participants (ten men and eight women) attended two sessions separated by 7 days. Participants were fitted with a trunk harness which was secured to an immovable base via a digital dynamometer. Three maximal voluntary isometric contractions were completed across four positions (prone, supine, left-side recumbent and right-side recumbent, respectively) on a glute-hamstring raise machine. All positions demonstrated excellent reliability and low variability within session (ICC: 0.95-0.98; CV: 5-7%) and between sessions (ICC: 0.98-0.99; CV: 4-6%), across all positions. The between-session MDC ranged from 8% (prone) to 13% (right-side recumbent), translating to absolute values between 2.9 and 3.2 kg across all positions. Maximal isometric force testing using a fixed digital dynamometer provides reliable measurements of multiplanar trunk strength, providing a practical method for use in clinical practice.

Interlimb and trunk asymmetry in the frontal plane of table tennis female players.

Background: An interesting and little-reported problem in the literature is the scale of asymmetry in table tennis players, the magnitude of which should perhaps be treated as a risk for injury. Determining the degree of asymmetry in table tennis players can indicate the need to appropriately manage the training process, including compensatory or corrective exercises in the training program, especially since recent studies confirm that training interventions can reduce sporting asymmetries and improve performance. This study aimed to assess the amount of asymmetry in the trunk regarding the frontal plane and the difference between limb circumferences in female table tennis players compared to the control group (non-athletes). Methods: Twenty-two women took part in the study. Ten of them were table tennis professionals with an average training experience of 7 ± 4.3 years (the exclusion criterion of the study was a minimum of 3 years of training experience). As a comparison group, the study included 12 female students who did not participate in competitive sports. Body posture was assessed in all subjects using equipment for computer analysis of asymmetry in the torso using the photogrammetric method. Additionally, all the subjects had their upper and lower limb circumferences measured. Results: The results of the conducted research showed asymmetry in the frontal plane in the table tennis player group. As many as six parameters-regarding the pelvic rotation angle, angle of trunk inclination, the height of the angles of the lower shoulder blades and their distance from the spine, as well as the waist triangles, difference in the width and height of the waist triangles and the angle of trunk inclination-indicated asymmetry in this group but significantly differed from the control group (p ≤ 0.05) only in the first parameter given above. The calculated differences in circumference between the right and left sides in the individual groups were statistically different in several cases (p ≤ 0.05). This concerned the circumferences of the arms, forearms, elbows, and knees of table tennis players. Conclusions: The research carried out in this study allowed us to determine the occurrence of asymmetry in the frontal plane of the trunk and between the limbs of table tennis players. According to some studies, this may be a risk factor for injury. However, despite the lack of uniform views in the literature on the importance and threats resulting from asymmetries, it appears that, if only for aesthetic reasons, table tennis would require compensatory or corrective training aimed at developing symmetry of the body structure.

Control strategies for trunk exoskeletons based on motion intent recognition: A review.

BACKGROUND: Wearable trunk exoskeletons hold immense potential in fields such as healthcare and industry. Previous research has indicated that intention recognition control plays a crucial role in users' daily use of exoskeletons. OBJECTIVE: This review aims to discuss the characteristics of intention recognition control schemes for intelligent trunk exoskeletons under different control objectives over the past decade. METHODS: Considering the relatively late development of active trunk exoskeletons, we selected papers published in the last decade (2013 to 2023) from the Web of Science, PubMed, and IEEE Xplore databases. In total, 50 articles were selected and examined based on four control objectives. RESULTS: In general, we found that researchers focus on trunk exoskeleton devices designed for assistance and motor augmentation, which rely more on body movement signals as a source for intention recognition. CONCLUSION: Based on these results, we identify and discuss several promising research directions that may help to attain a widely accepted control methods, thereby advancing further development of trunk exoskeleton technology.

The effect of hemispheric lesion location on trunk control.

BACKGROUND: Trunk control is the basic component of postural control, and achieving trunk control is a complex process that can be achieved by dynamically building and maintaining neuromuscular function. Lateropulsion, which is also defined as the body falling to one side, is considered an important condition that is frequently encountered after stroke and affects trunk control. It is known that there are differences in the regulation of postural control and trunk control according to hemispheric localization. We had a very specific group of patients and tried to find out the outcomes prospectively in this study. METHODS: The patients were divided into 2 groups those with right hemisphere lesions (Group 1) and those with left hemisphere lesions (Group 2). Comorbidity and cognitive function were evaluated using the Charlson Comorbidity Index (CMI) and Standardized Mini-Mental State Test (SMMSE). Activities of daily living were evaluated using the Turkish version of the Modified Barthel Index (MBI). The Stroke Rehabilitation Assessment of Movement Instrument (STREAM) test was used to assess trunk control and the Brunnstrom (BS) test was used to assess motor functions. RESULTS: There was a significant difference between Groups 1 and 2 in terms of STREAM in lower extremity scores were higher in Group 2 (P < .05). The number of patients in BS lower extremity Stages IV-VI was higher in Group 1 and Group 2 (P < .05). It was determined that upper extremity, lower extremity and Total STREAM scores and BS Hand stage in Group 2 were significantly higher than Group 1 in patients with total middle cerebral artery (MCA) affected(P < .05). CONCLUSION: It was determined that trunk control was more affected in patients with right hemispheric lesions. Additionally, trunk control is significantly affected in patients with total MCA lesions.

Reduced trunk muscle mass in patients with stroke is associated with reduced balance function recovery.

BACKGROUND & AIMS: Skeletal muscles are essential for postural retention and balance function. However, the relationship between trunk muscle mass (TMM) and balance function has not yet been clarified. This study aimed to examine the impact of TMM on the change in balance function in patients with stroke from admission to a rehabilitation hospital to discharge. METHODS: This retrospective observational study included patients aged ≥65 years with cerebral infarction admitted to our rehabilitation hospital from May 2018 to July 2022. The trunk muscle mass index (TMI) was calculated at admission and discharge using bioelectrical impedance analysis. Patients were divided into low and high TMI groups according to the median TMI at admission. The primary outcome was the change in the Berg Balance Scale (BBS) score (BBS score at discharge - BBS score at admission). RESULTS: A total of 315 patients (mean age, 78.9 ± 8.0 years; 172 men and 143 women) were included. The median TMI was 7.31 kg/m2 in men and 6.30 kg/m2 in women. Among male patients, the high TMI group had higher BBS scores at admission (31.2 ± 18.2 vs. 23.4 ± 17.7, P = 0.005) and discharge (43.0 ± 15.3 vs. 33.4 ± 19.0, P < 0.001) than those in the low TMI group. After adjusting for confounding factors, TMI at admission was independently associated with the change in BBS score (ß = 0.587, P = 0.002). CONCLUSIONS: Reduced TMM negatively influences balance function recovery in patients after stroke. A strategy aimed at increasing TMM could have beneficial effects on balance function.

Mitigating Trunk Compensatory Movements in Post-Stroke Survivors through Visual Feedback during Robotic-Assisted Arm Reaching Exercises.

Trunk compensatory movements frequently manifest during robotic-assisted arm reaching exercises for upper limb rehabilitation following a stroke, potentially impeding functional recovery. These aberrant movements are prevalent among stroke survivors and can hinder their progress in rehabilitation, making it crucial to address this issue. This study evaluated the efficacy of visual feedback, facilitated by an RGB-D camera, in reducing trunk compensation. In total, 17 able-bodied individuals and 18 stroke survivors performed reaching tasks under unrestricted trunk conditions and visual feedback conditions. In the visual feedback modalities, the target position was synchronized with trunk movement at ratios where the target moved at the same speed, double, and triple the trunk's motion speed, providing real-time feedback to the participants. Notably, trunk compensatory movements were significantly diminished when the target moved at the same speed and double the trunk's motion speed. Furthermore, these conditions exhibited an increase in the task completion time and perceived exertion among stroke survivors. This outcome suggests that visual feedback effectively heightened the task difficulty, thereby discouraging unnecessary trunk motion. The findings underscore the pivotal role of customized visual feedback in correcting aberrant upper limb movements among stroke survivors, potentially contributing to the advancement of robotic-assisted rehabilitation strategies. These insights advocate for the integration of visual feedback into rehabilitation exercises, highlighting its potential to foster more effective recovery pathways for post-stroke individuals by minimizing undesired compensatory motions.

Gait Variability as a Potential Motor Marker of Cerebellar Disease-Relationship between Variability of Stride, Arm Swing and Trunk Movements, and Walking Speed.

Excessive stride variability is a characteristic feature of cerebellar ataxias, even in pre-ataxic or prodromal disease stages. This study explores the relation of variability of arm swing and trunk deflection in relationship to stride length and gait speed in previously described cohorts of cerebellar disease and healthy elderly: we examined 10 patients with spinocerebellar ataxia type 14 (SCA), 12 patients with essential tremor (ET), and 67 healthy elderly (HE). Using inertial sensors, recordings of gait performance were conducted at different subjective walking speeds to delineate gait parameters and respective coefficients of variability (CoV). Comparisons across cohorts and walking speed categories revealed slower stride velocities in SCA and ET patients compared to HE, which was paralleled by reduced arm swing range of motion (RoM), peak velocity, and increased CoV of stride length, while no group differences were found for trunk deflections and their variability. Larger arm swing RoM, peak velocity, and stride length were predicted by higher gait velocity in all cohorts. Lower gait velocity predicted higher CoV values of trunk sagittal and horizontal deflections, as well as arm swing and stride length in ET and SCA patients, but not in HE. These findings highlight the role of arm movements in ataxic gait and the impact of gait velocity on variability, which are essential for defining disease manifestation and disease-related changes in longitudinal observations.

Instrumental Evaluation of the Effects of Vertebral Consolidation Surgery on Trunk Muscle Activations and Co-Activations in Patients with Multiple Myeloma: Preliminary Results.

Multiple myeloma (MM) patients complain of pain and stiffness limiting motility. To determine if patients can benefit from vertebroplasty, we assessed muscle activation and co-activation before and after surgery. Five patients with MM and five healthy controls performed sitting-to-standing and lifting tasks. Patients performed the task before and one month after surgery. Surface electromyography (sEMG) was recorded bilaterally over the erector spinae longissimus and rectus abdominis superior muscles to evaluate the trunk muscle activation and co-activation and their mean, maximum, and full width at half maximum were evaluated. Statistical analyses were performed to compare MM patients before and after the surgery, MM and healthy controls and to investigate any correlations between the muscle's parameters and the severity of pain in patients. The results reveal increased activations and co-activations after vertebroplasty as well as in comparison with healthy controls suggesting how MM patients try to control the trunk before and after vertebroplasty surgery. The findings confirm the beneficial effects of vertebral consolidation on the pain experienced by the patient, despite an overall increase in trunk muscle activation and co-activation. Therefore, it is important to provide patients with rehabilitation treatment early after surgery to facilitate the CNS to correctly stabilize the spine without overloading it with excessive co-activations.

Biomechanical analysis of trunk and lower limbs during stair activity in patients with scoliosis.

Staircases are a frequently encountered obstacle in daily life, requiring individuals to navigate ascending and descending movements that place additional demands on the trunk and lower limbs compared to walking on level surfaces. Therefore, it is crucial to examine the biomechanical characteristics of the trunk and lower limbs in individuals with scoliosis during stair activity. The aim of this study was to investigate the biomechanical differences in trunk and lower limbs during daily stair activities between patients with scoliosis and a healthy population. Additionally, the study aimed to explore the relationship between trunk abnormalities and lower limb biomechanics, providing a clinical and objective assessment basis for scoliosis. The Qualisys system, based in Gothenburg, Sweden, was employed for data collection in this study, with a sampling frequency of 150 Hz. It captured the kinematics of the trunk and lower limbs, as well as the kinetics of the lower limbs during stair ascent and descent for both the 28 individuals with scoliosis and the 28 control participants. The results indicate that scoliosis patients demonstrated significantly higher asymmetry compared to the control group in various measures during ascent and decent. These include different parts of kinematics and kinetics. Scoliosis patients demonstrate noticeable variations in their movement patterns compared to the healthy population when engaging in stair activities. Specifically, during stair ascent, scoliosis patients exhibit a seemingly more rigid movement pattern, whereas descent is characterized by an unstable pattern.

Inter- and intra-athlete technique variability of conventional new ball swing bowling in elite and pre-elite Australian male fast bowlers.

This study aimed to investigate inter- and intra-athlete technique variability in pre-elite and elite Australian fast bowlers delivering new ball conventional swing bowling. Ball grip angle and pelvis, torso, shoulder, elbow, wrist, upper arm, forearm, and hand kinematics were investigated at the point of ball release for inswing and outswing deliveries. Descriptive evaluations of group and individual data and k-means cluster analyses were used to assess inter- and intra-bowler technique variability. Inter-athlete technique and ball grip variability were identified, demonstrating that skilled bowlers use individualised strategies to generate swing. Functional movement variability was demonstrated by intra-athlete variability in successful swing bowling trials. Bowlers demonstrated stable technique parameters in large proximal body segments of the pelvis and torso, providing a level of repeatability to their bowling action. Greater variation was observed in bowling arm kinematics, allowing athletes to manipulate the finger and ball position to achieve the desired seam orientation at the point of ball release. This study demonstrates that skilled bowlers use individualised techniques and grips to generate swing and employ technique variations in successive deliveries. Coaches should employ individualised training strategies and use constraints-led approaches in training environments to encourage bowlers to seek adaptive movement solutions to generate swing.