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Context: Hip pain is associated with reduced hip muscle strength, range of movement (ROM), and decreased postural stability. Singleleg squat is a reliable and valid method to measure dynamic balance. Objective: To evaluate the influence of physical characteristics and use of a decline board on squat performance in a hip pain population. Design: Cross-sectional study setting. Clinical Patients: In total, 33 individuals scheduled for arthroscopic hip surgery were matched with 33 healthy controls. Interventions: Hip and ankle ROM, hip strength, and trunk endurance were assessed, along with knee and trunk kinematics during squat on flat and 25° decline surfaces. Main Outcome Measures: Between-group and surface differences in alignment, between-group strength and ROM, and associations between alignment and physical characteristics were assessed and determined using mixed model analysis of variance and Pearson R. Results: The hip pain group had significantly less strength and ROM for all directions except abduction strength and ankle dorsifiexion (P > .02). No differences existed between lire 2 groups for trunk (P < .70) or knee displacement (P < .46) during squat on either surface. When the 2 groups were combined (n = 66), decline squat significantly reduced knee medial displacement in both limbs by approximately 1 cm (P < .01). Decline squat reduced uxink lateral movement on 1 side only (P = .03). Reduced knee displacement during decline squat showed fair association with less hip-extension strength (r = -29), hip-flexion strength (r = -.25), and less dorsifiexion (r = -.24). Strength and range were not associated with trunk displacement. Conclusions: Decline squat reduced medial knee and lateral trunk displacement regardless of hip pain. Reductions may be greater in those with lesser hip muscle strength and dorsifiexion. Use of a decline board during squat for improving knee and trunk alignment should be considered as a goal of exercise intervention. [ABSTRACT FROM AUTHOR]

Context: It is important to validate single-leg squat visual rating criteria used in clinical practice and research. Foot orthoses may improve single-leg squat performance in those who demonstrate biomechanics associated with increased risk of lower limb injury. Objective: Validate visual rating criteria proposed by Crossley et al, by determining whether athletes rated as poor single-leg squat performers display different single-leg squat biomechanics than good performers; and evaluate immediate effects of foot orthoses on single-leg squat biomechanics in poor performers. Design: Comparative cross-sectional study. Setting: University laboratory. Participants: 79 asymptomatic athletes underwent video classification of single-leg squat performance based on established visual rating criteria (overall impression, trunk posture, pelvis "in space," hip movement, and knee movement), and were rated as good (n = 23), fair (n = 41), or poor (n = 15) performers. Intervention: A subset of good (n = 16) and poor (n = 12) performers underwent biomechanical assessment, completing 5 continuous single-leg squats on their dominant limb while 3-dimensional motion analysis and ground reaction force data were recorded. Poor performers repeated the task standing on prefabricated foot orthoses. Main Outcome Measures: Peak external knee adduction moment (KAM) and peak angles for the trunk, hip, knee, and ankle. Results: Compared with good performers, poor performers had a significantly lower peak KAM (mean difference = 0.11 Nm/kg, 95% confidence interval = 0.02 to 0.2 Nm/kg), higher peak hip adduction angle (−4.3°, −7.6° to −0.9°), and higher peak trunk axial rotation toward their stance limb (3.8°, 0.4° to 7.2°). Foot orthoses significantly increased the peak KAM in poor performers (−0.06 Nm/kg, −0.1 to −0.01 Nm/kg), with values approximating those observed in good performers. Conclusions: Findings validate Crossley et al's visual rating criteria for single-leg squat performance in asymptomatic athletes, and suggest that "off-the-shelf" foot orthoses may be a simple intervention for poor performers to normalize the magnitude of the external KAM during single-leg squat. [ABSTRACT FROM AUTHOR]

To investigate the sustainability of Robot-assisted upper limb therapy (RT-UL) as part of routine occupational therapy and physiotherapy clinical practice. Two separate audits, 12 months apart, of RT-UL computer data records were undertaken to determine sustainability in a subacute rehabilitation unit. Records of the two audits were compared in terms of the number of early subacute stroke survivors using RT-UL, the number of RT-UL sessions, duration of RT-UL sessions, and disciplines prescribing RT-UL. During Audit 1 58% (n = 18) of stroke survivors received RT-UL compared to 50% (n = 7) in Audit 2. The total number of RT-UL sessions reduced between audits (148 vs. 36 sessions) reflecting the overall reduction in admission rates for stroke survivors. There was no significant difference between audits in the average number of RT-UL sessions per patient (p = 0.203) nor the length of sessions (p = 0.762). Patients engaged in active therapy more than three-quarters of the time when on the robotic device. Physiotherapists were the primary prescribers of RT-UL when compared to occupational therapists. RT-UL was in continued and regular use with stroke survivors 2 years after initial implementation within an inpatient rehabilitation setting. RT-UL practice was intensive and used routinely with patients. RT-UL is a sustainable and intensive intervention for stroke survivors within an inpatient rehabilitative setting. The cost-benefits of RT-UL should be evaluated from the perspective of the whole rehabilitation service not just at an individual patient level. RT-UL may be considered a "bridging" form of UL practice for those with more limited active UL movement until there is sufficient UL movement and power for more complex real-world task-specific practice. [ABSTRACT FROM AUTHOR]

Frontal plane postures during the ultimate step of sidestepping are linked to increased anterior cruciate ligament injury risk. However, there is a lack of research detailing the kinematic strategies present in the penultimate step. This study, therefore, investigated penultimate and ultimate step kinematics of planned sidestepping (pSS) and unplanned sidestepping (upSS) to further understand the effect of planning time on known ultimate step kinematic and kinetic differences. Sixty male amateur Australian Rules football players performed three trials of straight‐line running (RUN), pSS, and upSS in a randomized order. Mediolateral foot placement and three‐dimensional joint kinematics for the knee, pelvis, and trunk were measured at final foot contact of the penultimate step and initial foot contact of the ultimate step. Peak knee moments were measured during the weight acceptance phase of the ultimate step. In pSS, at the penultimate step final foot contact, the support foot was placed across the midline of the center of mass, in the frontal plane, contralateral to the sidestep direction. Greater trunk lateral flexion toward the sidestep direction and greater negative pelvic lateral tilt were observed in pSS compared with upSS and RUN. Differences between pSS and upSS frontal plane kinematics at penultimate step final foot contact suggest preparatory reorientation strategies are likely constrained by the amount of planning time available. As there are clear differences in preparatory kinematics, we recommend that planning time be considered when training and assessing sidestepping maneuvers and planned and unplanned maneuvers not be treated as interchangeable skills. [ABSTRACT FROM AUTHOR]

To determine which potential contributing factors are associated with upper limb associated reaction (AR) expression in individuals with acquired brain injury (ABI). Forty-two participants underwent three-dimensional motion analysis at self-selected walking speed to generate the AR outcome measure, quantifying their upper limb kinematic deviation compared to healthy controls. Clinical assessment included: upper and lower limb hypertonicity, spasticity and strength, balance, dynamic walking stability, arm and leg function, anxiety, arm pain/discomfort, and fear of falling. Significant, moderate-to-strong correlations (r = 0.42–0.74, p < 0.05) existed between upper limb ARs and both hypertonicity and spasticity of the upper limb muscles and the knee extensors. Significant, moderate correlations to ARs (r = 0.42–0.59, p < 0.05) existed for balance, dynamic stability, upper limb strength, and arm function. The severity of AR was significantly different between those with and without hypertonicity of the four tested upper limb muscles, elbow and long finger flexor spasticity, knee extensor spasticity, and reduced dynamic stability (p < 0.05; effect sizes ≥0.80). However, these contributing factors were not present in all participants. Associated reactions are complex and multi-factorial. There were several significant correlations indicating that factors may influence AR severity. While positive upper motor neuron syndrome features should be prioritised for clinical assessment, these factors are not prerequisites for ARs. Upper limb associated reactions are a complex and multi-factorial phenomenon. Upper limb muscle hypertonicity and spasticity should be prioritised for assessment; however, they are not prerequisites for associated reactions. Hypertonicity and spasticity should be differentiated as they may have differing relationships to associated reactions. Knee extensor hypertonicity and spasticity, postural stability, upper limb strength, and arm function may also be contributing factors to consider. [ABSTRACT FROM AUTHOR]

Adolescent tennis players are at risk for low back pain (LBP). Recent research has demonstrated a potential mechanical etiology during serves; however, groundstrokes have also been suggested to load this region. Therefore, this study compared lumbar mechanics between players with and without a history of LBP during open and square stance tennis forehands and backhands. Nineteen elite, adolescent, male tennis players participated, 7 with a history of recurrent disabling LBP and 12 without. Differences in three-dimensional lumbar kinetics and kinematics were compared between pain/no pain groups and groundstrokes using linear mixed models (P < .01). There were no significant differences between pain/no pain groups. Relative to a right-handed player, groundstroke comparisons revealed that forehands had greater racquet velocity, greater lumbar right lateral flexion force, as well as upper lumbar extension/rightward rotation and lower lumbar right rotation/lateral flexion movements that were closer to or further beyond end of range than backhands. Backhands required upper lumbar leftward rotation that was beyond end range, while forehands did not. Given that players typically rotated near to their end of range during the backswing of both forehands and backhands, independent of pain, groundstrokes may contribute to the cumulative strain linked to LBP in tennis players. [ABSTRACT FROM AUTHOR]

Purpose: To investigate temporal variation in running intensity across and within halves and evaluate the agreement between match-analysis indices used to identify fluctuations in running intensity in rugby sevens. Methods: Data from a 15-Hz global positioning system (GPS) were collected from 12 elite rugby sevens players during the IRB World Sevens Series (N = 21 full games). Kinematic (eg, relative distance [RD]) and energetic (eg, metabolic power [MP]) match-analysis indices were deter- mined from velocity--time curves and used to investigate between-halves variations. Mean MP and RD were used to identify peak 2-minute periods of play. Adjacent 2-minute periods (prepeak and postpeak) were compared with peak periods to identify changes in intensity. MP and RD were expressed relative to maximal oxygen uptake ( ...O2max) and speed at ...O2max, respectively, and compared in their ability to describe the intensity of peak periods and their temporal occurrence. Results: Small to moderate reductions were present for kinematic (RD; 8.9%) and energetic (MP; 6%) indices between halves. Peak periods (RD = 130 m/min, MP =13 W/kg) were higher (P < .001) than the match average (RD = 94 m/min, MP = 9.5 W/kg) and the prepeak and postpeak periods (P < .001). RD underestimated the intensity of peak periods compared with MP (bias 16%, limits of agreement [LoA] ± 6%). Peak periods identified by RD and MP were temporally dissociated (bias 21 s, LoA ± 212 s). Conclusions: The findings suggest that running intensity varies between and within halves; however, the index used will influence both the magnitude and the temporal identification of peak periods. [ABSTRACT FROM AUTHOR]

Context: Accelerometer peak impact accelerations are being used to measure player physical demands in contact sports. However, their accuracy to do so has not been ascertained. Purpose: To compare peak-impact-acceleration data from an accelerometer contained in a wearable tracking device with a 3-dimensional motion-analysis (MA) system during tackling and bumping. Methods: Twenty-five semielite rugby athletes wore a tracking device containing a 100-Hz triaxial accelerometer (MinimaxX S4, Catapult Innovations, Australia). A single retroreflective marker was attached to the device, with its position recorded by a 12-camera MA system during 3 physical-collision tasks (tackle bag, bump pad, and tackle drill; N = 625). The accuracy, effect size, agreement, precision, and relative errors for each comparison were obtained as measures of accelerometer validity. Results: Physical-collision peak impact accelerations recorded by the accelerometer overestimated (mean bias 0.60 g) those recorded by the MA system (P < .01). Filtering the raw data at a 20-Hz cutoff improved the accelerometer's relationship with MA data (mean bias 0.01 g; P > .05). When considering the data in 9 magnitude bands, the strongest relationship with the MA system was found in the 3.0-g or less band, and the precision of the accelerometer tended to reduce as the magnitude of impact acceleration increased. Of the 3 movements performed, the tackle-bag task displayed the greatest validity with MA. Conclusions: The findings indicate that the MinimaxX S4 accelerometer can accurately measure physical-collision peak impact accelerations when data are filtered at a 20-Hz cutoff frequency. As a result, accelerometers may be useful to measure physical collisions in contact sports. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine if there is a relationship between pain and movement kinematics during functional tasks, evaluated over time, in individuals with chronic idiopathic neck pain. Ten participants with chronic idiopathic neck pain performed 2 functional tasks (overhead reach to the right and putting on a seatbelt) while evaluated using 8 Oqus 300+ cameras. Kinematic variables included joint angles and range of motion (ROM) (°), head segment relative to neck segment (head-neck [HN]); and head/neck segment relative to upper thoracic segment (head/neck-trunk), velocity (m/s), and time (% of movement phase). Pain was quantified using a 100-mm visual analog scale. Linear mixed effects regression models were used to analyze associations between pain and kinematic variables adjusting for treatment group. For overhead reach, higher pain was associated with less HN peak rotation at baseline (β = –0.33; 95% CI −0.52 to –0.14, P =.003) and less HN total rotation ROM at 6 months (β = –0.19; 95% CI –0.38 to –0.003, P =.048). For the seatbelt task, higher pain was associated with less HN peak rotation (β = –0.52; 95% CI −0.74 to –0.30 to –0.74, P <.001) and less HN total rotation ROM at baseline (β = –0.32; 95% CI –0.53 to –0.10, P =.006). No other movement variables demonstrated meaningful relationships with pain for the reach or seatbelt tasks. Higher pain is associated with less HN peak and total rotation during functional reaching tasks requiring head rotation. Recognizing altered functional kinematics in individuals with chronic neck pain may assist patient management. [ABSTRACT FROM AUTHOR]

Purpose:To assess the orthotic and therapeutic effects of prolonged use of functional electrical stimulation (FES) on fatigue induced gait patterns in people with Multiple Sclerosis (MS).Method:Thirteen people with MS completed 3D gait analysis with FES off and on, before and after a fatiguing 6-minute walk, at baseline and after 8 weeks of use of FES.Results:Eleven participants completed all testing. An orthotic effect on gait was not evident on first use of FES. However, therapeutic effects on gait after 8 weeks use were generally positive, including increases in walking speed due to improved neuromuscular control and power generated at the hip and ankle of the more affected limb. The action of FES alone was not sufficient to overcome all fatigue related deficits in gait but there was evidence 8 weeks use of FES can ameliorate some fatigue effects on lower limb kinetics, including benefits to ankle mechanics involved in generating power around push-off during stance.Conclusions:Eight-weeks of FES can benefit the gait pattern of people with MS under non-fatigued and fatigued conditions.Implications for rehabilitationIn some people with MS prolonged use of FES may be necessary before observing positive orthotic effects.Improvements in the neuromuscular control of the more affected lower limb may develop with prolonged use of FES in people with MS.Only some therapeutic benefits of FES are maintained during fatigued walking in people with MS.FES may be considered as a gait retraining device as well as an orthotic intervention for people with MS. [ABSTRACT FROM PUBLISHER]

Context: Because of the increasing popularity of participation in Irish dance, the incidence of lower limb injuries is high among this competitive population. Objective: To investigate the effects of fatigue on the peak lower limb and trunk angles as well as the peak lower limb joint forces and moments of competitive female Irish dancers during the performance of a dance-specific single-limb landing. Design: Cross-sectional study. Setting: Laboratory. Patients or Other Participants: Fourteen healthy, female, competitive Irish dancers (age = 19.4 ± 3.7 years, height = 165.3 ± 5.9 cm, mass = 57.9 ± 8.2 kg). Intervention(s): Participants performed an Irish dance- specific leap before and after a dance-specific fatigue protocol. During each landing movement, 3-dimensional lower limb kinematics (250 Hz) and ground reaction forces (1000 Hz) were collected. Paired t tests were performed to determine the differences (P ≤ .05) in lower limb and trunk biomechanics prefatigue and postfatigue. Main Outcome Measure(s): Peak lower limb and trunk angles as well as peak lower limb joint reaction forces and external moments. Results: Compared with the prefatigue trials, dancers landed with reduced ankle plantar flexion (P = .003) and hip external rotation (P = .007) and increased hip-adduction alignment (P = .034) postfatigue. Dancers displayed greater anterior shear (P = .003) and compressive (P = .024) forces at the ankle and greater external knee-flexion moments (P = .024) during the postfatigue compared with the prefatigue landing trials. Conclusions: When fatigued, dancers displayed a decline in landing performance in terms of aesthetics as well as increased ankle- and knee-joint loading, potentially exposing them to a greater risk of injuries. [ABSTRACT FROM AUTHOR]

Undulatory underwater swimming (UUS) is one of the major skills contributing to performance in competitive swimming. UUS has two phases- the upbeat is performed by hip extension and knee flexion, and the downbeat is the converse action. The purpose of this study was to determine which kinematic variables of the upbeat and downbeat are associated with prone UUS performance in an elite sample. Ten elite participants were filmed performing three prone 20 m UUS trials. Seven landmarks were manually digitised to calculate eighteen kinematic variables, plus the performance variable- horizontal centre of mass velocity (VCOM). Mean VCOM was significantly correlated with body wave velocity (upbeat r = 0.81, downbeat r = 0.72), vertical toe velocity (upbeat r = 0.71, downbeat r = 0.86), phase duration (upbeat r = -0.79), peak hip angular velocity (upbeat r = 0.73) and mean knee angular velocity (upbeat r = -0.63), all significant at P < 0.05. A multiple stepwise regression model explained 78% of variance in mean VCOM. Peak toe velocity explained 72% of the variance, and mean body wave velocity explained an additional 6%. Elite swimmers should strive for a high peak toe velocity and a fast caudal transfer of momentum to optimise underwater undulatory swimming performance. [ABSTRACT FROM AUTHOR]

This study aimed to explore how asymptomatic athletes with a patellar tendon abnormality (PTA), who are at high risk of developing patellar tendinopathy, alter their landing technique and net patellar tendon loads generated in response to fatigue. Seven asymptomatic players with a PTA performed five successful vertical stop-jump trials before and after a fatigue protocol. Fatigue protocol involved participants repeatedly performing sets of 30 submaximal jump exercises on a sledge apparatus followed by 30 s rest until the task failure criteria were reached. Three-dimensional ground reaction forces, lower limb kinematics and net peak patellar tendon force were recorded during the stop-jump task. No significant between-fatigue condition differences in net patellar tendon loading, or most secondary outcome variables were observed. Only some fatigue changes were seen during the vertical landing phase. Asymptomatic PTA participants did not modify their landing technique or net patellar tendon loading during a stop-jump task in response to fatigue. The lack of between-fatigue condition differences displayed by the asymptomatic PTA participants during both landing phases suggest that these individuals may not be capable of sufficient movement variability in their landing strategies to adapt to fatigue. [ABSTRACT FROM PUBLISHER]

Background and purpose The objective of this study is to compare the balance and gait of 11 people with multiple sclerosis (MS) to 11 healthy controls and to investigate the immediate change after a single intervention based on the Bobath concept on these activities in the MS group. Methods Balance was assessed by ground reaction forces (GRF) and centre of pressure movements during single limb standing (SLS), the Lateral Reach Test (LRT) and the Four Square Step Test (FSST). Gait was evaluated by GRF, ankle kinematics and spatiotemporal measures. Results Baseline measures in the MS group showed significantly greater vertical GRF variability ( p = 0.008) during SLS reached less distance on the LRT ( p = 0.001) and were slower completing the FSST ( p < 0.001). During gait, the MS group walked slower ( p = 0.005) and had less ankle plantarflexion (PF) ( p = 0.001) than the control group. Less peak vertical GRF ( p < 0.001) and peak propulsive GRF ( p = 0.004) at terminal stance and increased vertical GRF in midstance ( p = 0.005) were observed. The measures of balance and gait were re-assessed in the MS group immediately after a 20-min intervention based on the Bobath concept delivered to the most impaired foot and ankle. After the intervention, the MS group had significant changes towards the control group values with reduced mediolateral ( p = 0.002) and vertical ( p = 0.016) GRF variability in the SLS task, faster FSST time ( p = 0.006) and increased ankle PF during gait ( p = 0.002). Discussion This study provides further evidence of balance and gait limitations in people with MS and indicates that a single treatment based on principles of the Bobath concept to the foot and ankle can result in immediate improvements in balance and ankle PF during gait in people with MS. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Study Design Controlled laboratory study. Objective To evaluate the ability of 3 methods to assess static foot posture to predict rearfoot and midfoot kinematics during gait. Background Static foot posture is commonly used clinically to infer dynamic function. Limitations of static clinical assessments may be overcome through advances in technologies, including commercially available depth cameras. Methods The Foot Posture Index (FPI) of 31 males (average age, 22.5 years) was assessed using visual observation, a 3-D motion-analysis system, and a depth camera. Pearson correlations were used to evaluate relationships between FPI items and rearfoot and midfoot kinematics during walking. The ability of the static variables to predict dynamic function was assessed using multiple linear regression. Results Most FPI items (85%) were not correlated with foot kinematics, regardless of assessment method. There were 6 fair to moderate correlations between visual FPI items and total rearfoot (r = -0.36 to -0.39, P<.05) and midfoot (r = 0.37 to 0.61, P<.05) motion, 2 fair correlations between 3-D motion-analysis FPI items and total midfoot (r = -0.43, P = .02) and peak rearfoot (r = -0.40, P = .03) motion, and 2 fair correlations between the depth-camera FPI items and average rearfoot (r = -0.38 to 0.44, P<.05) motion. Visual assessment of the FPI provided the best prediction model, explaining 37% of the variance in total midfoot inversion/eversion. Conclusion Static measures of foot posture are weakly correlated with rearfoot or midfoot kinematics, and have limited dynamic prediction ability. Our findings suggest that the FPI may not be an accurate representation of rearfoot or midfoot movement during walking, regardless of the measurement technique employed. [ABSTRACT FROM AUTHOR]

Patellar tendinopathy is the most common knee injury incurred in volleyball, with its prevalence in elite athletes more than three times that of their sub-elite counterparts. The purpose of this study was to determine whether patellar tendinopathy risk factors differed between elite and sub-elite male volleyball players. Nine elite and nine sub-elite male volleyball players performed a lateral stop-jump block movement. Maximum vertical jump, training history, muscle extensibility and strength, three-dimensional landing kinematics (250 Hz), along with lower limb neuromuscular activation patterns (1500 Hz), and patellar tendon loading were collected during each trial. Multivariate analyses of variance ( P < 0.05) assessed for between-group differences in risk factors or patellar tendon loading. Significant interaction effects were further evaluated using post-hoc univariate analysis of variance tests. Landing kinematics, neuromuscular activation patterns, patellar tendon loading, and most of the previously identified risk factors did not differ between the elite and sub-elite players. However, elite players participated in a higher training volume and had less quadriceps extensibility than sub-elite players. Therefore, high training volume is likely the primary contributor to the injury discrepancy between elite and sub-elite volleyball players. Interventions designed to reduce landing frequency and improve quadriceps extensibility are recommended to reduce patellar tendinopathy prevalence in volleyball players. [ABSTRACT FROM AUTHOR]

The aim of this study was to simultaneously assess the changes in physiology, and kinematic and spatiotemporal features of gait, during prolonged load carriage in individuals without load carriage experience. Eleven males, representative of new military recruits, walked for 120 min at 5.5 km h− 1, 0% grade, on a motorised treadmill while carrying a 22 kg load. The load ( ≤ 30% body mass) was distributed over a weighted vest, combat webbing and replica model firearm, to reflect a patrol order load. Oxygen consumption and heart rate increased throughout the trial; however, apart from a minor increase in step length, there were no changes in the kinematic or spatiotemporal parameters, despite an increase in perceived exertion and discomfort. These data suggest that individuals with no experience in load carriage are able to maintain normal gait during 2 h of fixed speed walking, while carrying a patrol order load ≤ 30% body mass. Practitioner Summary:It is presumed that lower limb injury is associated with prolonged load carriage, especially in new military recruits. Our results suggest that prolonged carriage of a 22 kg load does not cause any functionally relevant gross biomechanical changes despite an increase in the physiological demands and perceived intensity of the task. [ABSTRACT FROM AUTHOR]

This study examined the perceived effort, success rates and kinematics for three push strategies in a simulated lateral patient transfer (horizontal slide). Thirteen healthy subjects (four males) completed three repetition pushing loads of 6, 10 and 14 kg in random order; with a spontaneous push strategy, then with a straight-back bent-knees (squat) strategy and the preparatory pelvic movement (‘rockback’) strategy in random order. Perceived effort and kinematic parameters measured at the onset of movement and at maximum push excursion were compared between strategies and between loads with repeated measures ANOVA. The spontaneous and ‘rockback’ strategies achieved the pushing task with less perceived effort across all loads than the squat push (P < 0.001). Only 3/13 participants were successful on all attempts at pushing the 14 kg load using a squat strategy, which contrasted with 12/13 participants when the spontaneous strategy or the ‘rockback’ strategy was used. Forward movement of the pelvis and forward trunk inclination may be positively associated with lower perceived effort in the push task. Practitioner Summary:In a manual-handling task that simulated a lateral patient transfer (horizontal slide), perceived effort and success rates of three push strategies were compared. A straight-back bent-knees push (squat) strategy demonstrated greater perceived effort and lower success rates than a spontaneous push strategy, or a push strategy with preparatory ‘rockback’ pelvic movement. [ABSTRACT FROM AUTHOR]

In Australian football (AF), handballing proficiently with both the preferred and non-preferred arm is important at elite levels; yet, little information is available for handballing on the non-preferred arm. This study compared preferred and non-preferred arm handballing techniques. Optotrak Certus (100 Hz) collected three-dimensional data for 19 elite AF players performing handballs with the preferred and non-preferred arms. Position data, range of motion (ROM), and linear and angular velocities were collected and compared between preferred and non-preferred arms using dependentt-tests. The preferred arm exhibited significantly greater forearm and humerus ROM and angular velocity and significantly greater shoulder angular velocity at ball contact compared to the non-preferred arm. In addition, the preferred arm produced a significantly greater range of lateral bend and maximum lower-trunk speed, maximum strike-side hip speed and hand speed at ball contact than the non-preferred arm. The non-preferred arm exhibited a significantly greater shoulder angle and lower- and upper-trunk orientation angle, but significantly lower support-elbow angle, trunk ROM, and trunk rotation velocity compared to the preferred arm. Reduced ROM and angular velocities found in non-preferred arm handballs indicates a reduction in the degrees of freedom and a less developed skill. Findings have implication for development of handballing on the non-preferred arm. [ABSTRACT FROM AUTHOR]

BACKGROUND: The safe maximal lift for a person is often determined during a functional capacity evaluation. This determination is based upon observation of unsafe lifting techniques, however there is limited information on specific kinematic changes that assist a therapist's clinical reasoning and determination of the safe maximal lift. OBJECTIVE: To evaluate any change in kinematics between safe minimum and safe maximum floor-to-bench lifts during the WorkHab Functional Capacity Evaluation. METHOD: Twenty-eight healthy participants (age range 18-22 years) were digitally recorded completing the evaluation. Lumbar spine, hip, knee and ankle joint angles were measured using Dartfish Pro-suite software at the beginning (0/3), one third (1/3), two thirds (2/3) and end (3/3) of the lift in descending and ascending phases. Paired t-tests were used to compare joint angles at each point of minimum and safe maximum lifts. RESULTS: Significant changes in joint angles occurred lifting safe maximum weight compared to minimum weight. The lumbar spine was in greater flexion [4.9, 95% CI 2.1:7.7, p=0.001]; the knee joint was in less flexion descending [-4.5, 95% CI -8.1: -0.8, p=0.004 (3/3)] and ascending [-9.7, 95% CI -18.3: -1.16, p=0.027 (0/3)] and hip flexion increased at all points of the ascending phase (p&les; 0.021). The ankle joint was in less dorsiflexion while descending [8.0, 95% CI 3.4:12.7, p=0.001(2/3); 6.7, 95% CI 4.4:9.0, p&les;0.001(3/3)] and ascending [8.9, 95% CI 6.24:11.6, p=0.001(0/3); 3.6, 95% CI 1.5:5.7, p&les;0.001(3/3)]. CONCLUSIONS: This study provides insight into kinematic changes and support observations made by the WorkHab assessor in determining a safe maximal lift during floor-to-bench lifts. [ABSTRACT FROM AUTHOR]

The handball pass is influential in Australian football, and achieving higher ball speeds in flight is an advantage in increasing distance and reducing the chance of interceptions. The purpose of this study was to provide descriptive kinematic data and identify key technical aspects of maximal handball performance. Three-dimensional full body kinematic data from 19 professional Australian football players performing handball pass for maximal speed were collected, and the hand speed at ball contact was used to determine performance. Sixty-four kinematic parameters initially obtained were reduced to 15, and then grouped into like components through a two-stage supervised principal components analysis procedure. These components were then entered into a multiple regression analysis, which indicated that greater hand speed was associated with greater shoulder angular velocity and separation angle between the shoulders and pelvis at ball contact, as well as an earlier time of maximum upper-trunk rotation velocity. These data suggested that in order to increase the speed of the handball pass in Australian football, strategies like increased shoulder angular velocity, increased separation angle at ball contact, and earlier achievement of upper-trunk rotation speed might be beneficial. [ABSTRACT FROM PUBLISHER]

Office workers perform tasks using different information and communication technologies (ICT) involving various postures. Adequate variation in postures and muscle activity is generally believed to protect against musculoskeletal complaints, but insufficient information exists regarding the effect on postural variation of using different ICT. Thus, this study among office workers aimed to determine and compare postures and postural variation associated with using distinct types of ICT. Upper arm, head and trunk postures of 24 office workers were measured with the Physiometer® over a whole day in their natural work and away-from-work environments. Postural variation was quantified using two indices: APDF(90-10)and EVA(sd). Various ICT had different postural means and variation. Paper-based tasks had more non-neutral, yet also more variable postures. Electronics-based tasks had more neutral postures, with less postural variability. Tasks simultaneously using paper- and electronics-based ICT had least neutral and least variable postures. Tasks without ICT usually had the most posture variability. Interspersing tasks involving different ICT could increase overall exposure variation among office workers and may thus contribute to musculoskeletal risk reduction. Practitioner Summary:This study in office workers assessed posture variation, which is believed to protect against musculoskeletal complaints. Electronics-based tasks had more neutral upper body postures but less posture variation than other tasks. Combining tasks based on different technologies could increase postural variation in and outside the job for office workers. [ABSTRACT FROM AUTHOR]