The Midfoot Joint Complex (Foot Arch) Contributes to the Upper Body Position in Bipedal Walking and Coordinates With the Lower Limb Joints.

This study estimated the contribution of the midfoot joint complex (MJC) kinematics to the pelvis anterior-posterior positions during the stance phase of walking and investigated whether the MJC is functionally coordinated with the lower limb joints to maintain similar pelvic positions across steps. Hip, knee, ankle, and MJC sagittal angles were measured in 11 nondisabled participants during walking. The joints' contributions to pelvic positions were computed through equations derived from a link-segment model. Functional coordination across steps was identified when the MJC contribution to pelvic position varied and the summed contributions of other joints varied in the opposite direction (strong negative covariations [r ≤ -.7] in stance phase instants). We observed that the MJC plantarflexion (arch raising) during the midstance and late stance leads the pelvis backward, avoiding excessive forward displacement. The MJC was the second joint that contributed most to the pelvis positions (around 18% of all joints' contributions), after the ankle joint. The MJC and ankle were the joints that were most frequently coordinated with the other joints (≅70% of the stance phase duration). The findings suggest that the MJC is part of the kinematic chain that determines pelvis positions during walking and is functionally coordinated with the lower limb joints.

New Optimized Dynamic Calibration Proposition for Discretized Sensorized Insoles With Resistive Force Sensor: A Descriptive and Comparative Study.

Sensorized insoles (SIs) have been used as a wearable instrument to study human gait and have the potential to identify and predict pathologies and injuries. However, most of these sensorized insoles are only statically calibrated, relying on a scale and known weights to establish a relationship between electrical signals and the load applied on laboratory benches while ignoring the dynamic interaction between person and instrument. This study proposes and verifies a calibration method complementary to static calibration to compensate for different dynamic interactions between the insole and the individual during gait. In order to perform this comparison, a laboratory test was proposed with 32 volunteers (18 men and 14 women). Each volunteer walked on a double-belt instrumented treadmill (Bertec at 1000 Hz, Bertec Corp, Columbus, OH) while wearing an experimental resistive sensorized insole (SI). The SI data were compared with the instrumented treadmill and adjusted using an optimization algorithm to create a dynamic coefficient to complement and optimize the results. This study also verifies the impact of the method considering three different types of gait: pronated, neutral, and supinated. After using this technique and considering static calibration, the Pearson correlation coefficient between the SI and the instrumented treadmill improved by 12%.

Effects of Resistance Training of Upper Limb and Trunk Muscles on Soccer Instep Kick Kinematics.

The upper body and trunk muscles are crucial to perform soccer kicks. Resistance training targeting these muscles may modify the pattern adopted during kicking. This study aimed to investigate the effect of resistance training of the arm and anterior trunk muscles on instep kicking kinematics. Twenty-six male participants were randomly allocated into a training group or control group. The training group underwent resistance training of arm and trunk muscles and practiced the instep kick for 8 weeks. The control group only practiced kicking during the same period. The trunk, hip, and knee kinematics were assessed during the instep kick before and after the intervention. Kinematics were analyzed according to their data distribution with statistical parametric or nonparametric mapping. The effect of the training on the 1-repetition maximum test was analyzed using a repeated-measures multivariate analysis of variance. The training group showed greater hip extension after the training during the backswing phase (Hedge g effect size of 0.316-0.321) and increased 1-repetition maximum for all exercises. There were no other differences. The present study documented the nonlocal effect of strengthening training in which arm and trunk muscle training resulted in changes in hip kinematics during the backswing phase of the instep kick.

Association of Cycling Kinematics With Anterior Knee Pain in Mountain Bike Cyclists.

CONTEXT: Comfort and pain in cyclists are often discussed as a result of the posture on the bike, and bike fit, including motion analysis, is advocated as a strategy to minimize these conditions. The relationship between cycling kinematics, comfort, and pain is still debatable. OBJECTIVES: To investigate the association of ankle, knee, and trunk kinematics with the occurrence of anterior knee pain (AKP) in mountain bike cyclists. DESIGN: Cross-sectional study. METHODS: Fifty cross-country mountain bike cyclists (26 with AKP and 24 without AKP) had their pedaling kinematics assessed. Linear and angular data from trunk, hip, knee, ankle, and foot from cyclists with and without AKP were recorded using Retül motion analysis system. RESULTS: The binary logistic regression model showed that kinematic variables such as peak ankle plantar flexion, peak knee flexion, and forward trunk lean were significant predictors of AKP. Both larger peak plantar flexion and knee flexion decreased the probability of reporting AKP. On the other hand, larger forward trunk lean increased the probability of reporting AKP. CONCLUSIONS: Ankle, knee, and trunk sagittal kinematics may predict AKP in cross-country mountain bike cyclists, whereas hip, knee, and ankle alignment in the frontal plane showed no association with occurrence of AKP. In other words, cyclists with larger ankle plantar flexion and knee flexion are less likely to have AKP, whereas those with increased trunk forward lean are more likely to have AKP.

Current Technologies and Practices to Assess External Training Load in Paralympic Sport: A Systematic Review.

CONTEXT: Knowing the methods to assess the external load in Paralympic sports can help multidisciplinary teams rely on scientific evidence to better prescribe and monitor the athlete's development, improving sports performance and reducing the risk of injury/illness of Paralympic athletes. OBJECTIVES: This review aimed to systematically explore the current practices of quantifying the external load in Paralympic sports and provide an overview of the methods and techniques used. EVIDENCE ACQUISITION: A search in PubMed, Web of Science, Scopus, and EBSCO was carried out until November 2022. The measures of interest were objective methods for quantifying the external load of training or competition. The inclusion criteria for the studies were as follows: (1) peer-reviewed article; (2) the population were Paralympic athletes; (3) evaluated during training or competition; (4) reported at least one external load measure; and (5) published in English, Portuguese, or Spanish. EVIDENCE SYNTHESIS: Of the 1961 articles found, 22 were included because they met the criteria, and 8 methods were identified to quantify the external load in training or competition in 8 Paralympic sports. The methods varied according to the characteristics of the Paralympic sports. To date, the devices used included an internal radiofrequency-based tracking system (wheelchair rugby) a miniaturized data logger (wheelchair tennis, basketball, and rugby); a linear position transducer (powerlifting and wheelchair basketball); a camera (swimming, goalball, and wheelchair rugby); a global positioning system (wheelchair tennis); heart rate monitors that assess external load variables in set (paracycling and swimming) and an electronic timer (swimming). CONCLUSIONS: Different objective methods were identified to assess the external load in Paralympic sports. However, few studies showed the validity and reliability of these methods. Further studies are needed to compare different methods of external load quantification in other Paralympic sports.

The Sleep Parameters of Paralympic Athletes: Characteristics and Assessment Instruments.

CONTEXT: Sleep serves many important functions for athletes, particularly in the processes of learning, memory, recovery, and cognition. OBJECTIVES: Define the sleep parameters of Paralympic athletes and identify the instruments used to assess and monitor sleep Paralympic athletes. EVIDENCE ACQUISITION: This systematic review was carried out based on the PRISMA guidelines. The survey was conducted in April 2020, the searches were carried out again in September 2021 to check whether there were new scientific publications in the area of sleep and Paralympic sport, searches were performed in the following databases: PubMed, Web of Science, Scopus, SPORTDiscus, Virtual Health Library (BIREME), and SciELO. This systematic review has included studies that investigated at least one of the following sleep parameters: total sleep time, sleep latency, sleep efficiency, number of awakenings, quality of sleep, daytime sleepiness, and chronotype; the participants were comprised of athletes with disabilities. Studies published at any time in English, Portuguese, and Spanish, were included. EVIDENCE SYNTHESIS: Data extraction and study selection were performed by 2 researchers independently, and a third author was consulted as necessary. The search returned a total of 407 studies. Following the screening based on exclusion and inclusion criteria, a total of 13 studies were considered. Paralympic athletes have a low amount (7.06 h) of sleep with poor quality and sleep latency (28.05 min), and 57.2% have daytime sleepiness, with the majority belonging to the indifferent chronotype (53, 5%). Moreover, 11 studies assess sleep using subjective instruments (questionnaires), and 2 studies used an objective instrument (actigraphy). CONCLUSIONS: Sleep disorders are common among Paralympic athletes, poor sleep quality and quantity, and high rates of daytime sleepiness. Subjective methods are most commonly used to assess sleep.

Spinal cord injury and work challenges: an analysis of paid work status and pathways of return to work in Brazil.

DESIGN: Retrospective cohort study. OBJECTIVES: To investigate paid work status and return to work (RTW) pathways after spinal cord injury (SCI). SETTING: SARAH Network of Rehabilitation Hospitals. METHODS: Participants were adults with traumatic SCI, aged between 18 and 60 years at the time of the injury, admitted between 2000 and 2017. In the first stage, socio-demographic, injury-related, and functional status data were collected from medical records. In the second stage, data on paid work, means of mobility, driving ability, return to study, ability to work, and satisfaction with the work status were collected through an online survey conducted between January and March 2020. RESULTS: A total of 154 participants were included in the sample. Of these, 90% were working at the time of SCI and 23% were engaged in paid work at the time of the study. Three RTW pathways were identified among those who were working at the time of the injury and: did not return to work (78%); returned to a different occupation (12%) and returned to the same occupation (9%). Number of post-injury complications, returning to study, good work ability, and satisfaction with the work status were predictors of paid work. The model's adjusted coefficient was 56.5% (p = 0.001). CONCLUSION: Working-age people with SCI who underwent rehabilitation in Brazil had a low rate of paid work. Fewer complications at the time of the injury, returning to study, good ability to work and greater satisfaction with the work status increased the likelihood of being engaged in paid work.

Effectiveness of exercises by telerehabilitation on pain, physical function and quality of life in people with physical disabilities: a systematic review of randomised controlled trials with GRADE recommendations.

OBJECTIVE: Investigate whether exercise-based telerehabilitation improves pain, physical function and quality of life in adults with physical disabilities. DESIGN: Systematic review of randomised controlled trials. DATA SOURCES: Searches were performed in AMED, MEDLINE, CINAHL, SPORTDiscus, Embase, PEDro, Cochrane Library and PsycINFO. ELIGIBILITY CRITERIA: Trials were considered if they evaluated exercise by telerehabilitation. The population included adults with physical disability. Comparisons were control and other interventions. The outcomes were pain, physical function and quality of life. Study selection, data extraction and analysis followed the protocol registered in PROSPERO (CRD42019122824). GRADE determined the strength of evidence. RESULTS: Forty-eight trials were included in the quantitative analysis. When compared with other interventions, there was high-quality evidence that telerehabilitation was not different to other interventions for pain (95% CI: -0.4 to 0.1), physical function (95% CI: -0.2 to 0.2) and quality of life (95% CI: -0.1 to 0.5) at long-term. There was moderate-quality evidence that telerehabilitation was not different to other interventions for physical function (95% CI: -0.1 to 0.5) and quality of life (95% CI: -0.2 to 0.5) at short-term. However, due to the low-quality evidence and the small number of trials comparing exercise protocols offered by telerehabilitation with control groups, it is still not possible to state the efficacy of telerehabilitation on pain, function and quality of life at short-term and long-term. CONCLUSIONS: Exercise by telerehabilitation may be an alternative to treat pain, physical function and quality of life in adults with physical disabilities when compared with other intervention.

Prevalence and incidence of injuries in para athletes: a systematic review with meta-analysis and GRADE recommendations.

OBJECTIVE: To investigate prevalence, incidence and profile of musculoskeletal injuries in para athletes. DESIGN: Systematic review. DATA SOURCES: Searches were conducted in MEDLINE, EMBASE, AMED, SPORTSDiscus, CINAHL and hand searching. ELIGIBILITY CRITERIA: Studies were considered if they reported prevalence or incidence of musculoskeletal injuries in para athletes. Study selection, data extraction and analysis followed the protocol. Meta-analyses were conducted to estimate the prevalence and incidence rate among studies and subgroup analyses investigated whether methodological quality and sample size of the studies influenced on the estimated injury prevalence and incidence. The Grading of Recommendations Assessment, Development and Evaluation system determined the strength of evidence. RESULTS: Forty-two studies were included. The prevalence of musculoskeletal injuries was 40.8% (95% CI 32.5% to 49.8%). Because of imprecision, indirectness and inconsistency, the strength of evidence was very low quality. The incidence of musculoskeletal injuries was 14.3 injuries per 1000 athlete-days (95% CI 11.9 to 16.8). The strength of evidence was low quality because of imprecision and indirectness. The subgroup analyses revealed that the sample size influenced on estimated injury prevalence and methodological quality influenced on estimated incidence. Injuries were more prevalent in the shoulder, for non-ambulant para athletes, and in the lower limbs, for ambulant para athletes. SUMMARY/CONCLUSION: Para athletes show high prevalence and incidence of musculoskeletal injuries. Current very low-quality and low-quality evidence suggests that future high-quality studies with systematic data collection, larger sample size and specificities of para athletes are likely to change estimates of injury prevalence and incidence in para athletes. PROSPERO REGISTRATION NUMBER: CRD42020147982.

Reliability of a Low-Cost Assessment of Tibial Torsion and Transverse-Plane Posture of the Lower Limb and Pelvis Using a Smartphone Compass.

OBJECTIVES: The purpose of this study was to investigate intra- and interrater reliability and minimal detectable change (MDC) of clinical measures proposed to assess tibial torsion and the posture of the lower limbs and pelvis in the transverse plane. METHODS: Twenty-five able-bodied and asymptomatic participants (mean age 27 ± 4.03, 12 women) were assessed during relaxed standing with a compass application on a smartphone coupled to a caliper. Two trained examiners measured tibial torsion and angular postures of the pelvis, hip, femur, and tibia. Intraclass correlation coefficients (ICC) were used to investigate reliabilities, and MDCs were calculated. RESULTS: The results showed predominantly good-to-excellent reliability for the measures of the femur, hip, and tibia postures and tibial torsion (0.77 < ICC < 0.94), including some moderate-to-good reliability (0.65 < ICC < 0.75). The pelvic posture measure was predominantly moderate to good (0.55 < ICC < 0.86). MDCs have been reported (2.14°-7.86°) to assist clinicians in identifying postural changes that are within or outside the random measure variation. CONCLUSION: The use of a smartphone digital compass coupled to a caliper showed to be a reliable method to assess tibial torsion and transverse-plane postures of the lower limb and pelvis.

Altered Scapular Time Series in Individuals With Subacromial Pain Syndrome.

Altered scapular movement in subacromial pain syndrome has been demonstrated using discrete data reduction approach. However, this approach does not consider the data collinearity and variability, and scapular translations are poorly investigated in symptomatic individuals. The purpose of this study was to investigate the scapular rotation and translation of asymptomatic individuals and those with subacromial pain syndrome during arm motions using principal component analysis. Scapulothoracic kinematics were evaluated in 47 participants with subacromial pain syndrome and 50 asymptomatic individuals. The symptomatic group had increased range of scapular anterior/posterior tilt during arm elevation (P = .01, effect size = .59) and arm lowering (P < .01, effect size = .61), and increased range of scapular forward/backward translation during arm lowering (P < .01, effect size = .60) compared with the asymptomatic group. In addition, the symptomatic group had a reduced difference in anterior tilt angular velocities between the early-arm and mid-arm lowering phases and between the mid- and late-arm lowering phases compared with the asymptomatic group (P = .03, effect size = .44). This study demonstrated that scapular anterior/posterior tilt motion and angular velocity and scapular forward/backward translation of symptomatic individuals were different from asymptomatic individuals when considering the entire arm movement.

Functional Task Training Combined With Electrical Stimulation Improves Motor Capacity in Children With Unilateral Cerebral Palsy: A Single-Subject Design.

PURPOSE: Reduced propulsive capability can impact negatively on mobility activities of many children with spastic unilateral cerebral palsy (SUCP). This study investigated the effect of a task-oriented training program combined with functional electrical stimulation (FES) on the motor capacity of children with SUCP. METHODS: Single-case A-B design with follow-up. Gross motor function and biomechanical walking data of 4 children with SUCP were measured repeatedly across the baseline, intervention, and follow-up phases. Intervention was a task-oriented training program combined with FES applied on the gastrocnemius. Outcome variables included gait speed, impulsive torque, and ankle/hip power generation ratio. The 2-SD band and celeration line methods compared outcomes among the baseline, intervention, and follow-up periods. RESULTS: One child improved walking speed. All children improved impulsive torque and ankle/hip power ratio of the affected leg. All children improved gross motor function. CONCLUSION: The intervention improved children's propulsive capability and positively influenced their mobility.

A Global Gait Asymmetry Index.

High levels of gait asymmetry are associated with many pathologies. Our long-term goal is to improve gait symmetry through real-time biofeedback of a symmetry index. Symmetry is often reported as a single metric or a collective signature of multiple discrete measures. While this is useful for assessment, incorporating multiple feedback metrics presents too much information for most subjects to use as visual feedback for gait retraining. The aim of this article was to develop a global gait asymmetry (GGA) score that could be used as a biofeedback metric for gait retraining and to test the effectiveness of the GGA for classifying artificially-induced asymmetry. Eighteen participants (11 males; age 26.9 y [SD = 7.7]; height 1.8 m [SD = 0.1]; body mass 72.7 kg [SD = 8.9]) walked on a treadmill in 3 symmetry conditions, induced by wearing custom-made sandals: a symmetric condition (identical sandals) and 2 asymmetric conditions (different sandals). The GGA score was calculated, based on several joint angles, and compared between conditions. Significant differences were found among all conditions (P < .001), meaning that the GGA score is sensitive to different levels of asymmetry, and may be useful for rehabilitation and assessment.

Prevalence and incidence of health problems and their characteristics in Brazilian para athletes: A one-season single-center prospective pilot study.

BACKGROUND: Para athletes experience high prevalence and incidence of health problems related to sport. Despite this, there are few longitudinal studies. OBJECTIVE: To describe the characteristics, prevalence, incidence, and severity of health problems in para athletes from one of the Brazilian Paralympic Reference Centers during a sports season and to compare the prevalence of health problems between para athletics, para powerlifting, and para swimming. METHODS: This prospective pilot study was conducted from October 2019 to March 2020. The Oslo Sports Trauma Research Center Questionnaire on Health Problems was used to record injuries and illnesses every week for 24 weeks. The characteristics, prevalence, incidence, and severity of health problems were described for each modality. The prevalence of health problems was compared among the three sport modalities. RESULTS: Thirty-five para athletes participated. Most of the injuries occurred in the shoulder, and most illnesses caused respiratory and gastrointestinal symptoms. The average weekly prevalence and the incidence rate of health problems were 40.6% (95% CI 17.0-64.4) and 12.7 (95% CI 9.6-15.9) per 1000 athlete hours, respectively. Para powerlifting had the highest prevalence of all and substantial health problems; para swimming had the lowest prevalence of injuries; and para athletics had the lowest prevalence of illnesses. CONCLUSIONS: This group of Brazilian para athletes showed a high prevalence and incidence of health problems throughout the season. Para athletics, para powerlifting, and para swimming each had a different prevalence of injuries and illnesses.

Influence of reduced passive ankle dorsiflexion range of motion on lower limb kinetics and stiffness during gait.

BACKGROUND: The ankle dorsiflexion range of motion (ADF-ROM) during single support phase allows elastic energy storage in the calcaneal tendon, contributing to advance the body forward. Reduced ADF-ROM may influence lower limb kinetics and stiffness. RESEARCH QUESTION: What is the influence of reduced passive ADF-ROM on lower limb internal moments and stiffness during gait? METHODS: Thirty-two participants, classified into two groups according to passive ADF-ROM (smaller than 10° and greater than 15°), were submitted to gait assessment at self-selected speed with a force platform and a three-dimensional motion analysis system. Statistical parametrical mapping (SPM) analyses were used to compare the lower limbs' internal moments between groups. Independent t-tests analyzed the differences between groups on lower limb stiffness during gait. RESULTS: The lower ADF-ROM group had greater knee flexor moment (terminal stance and push-off), greater ankle abductor (i.e., shank internal rotator) moment in terminal stance and greater knee internal rotator moment in mid to terminal stance. The lower ADF-ROM group also had higher lower limb stiffness during gait. SIGNIFICANCE: Individuals with reduced passive ADF-ROM had greater lower limb stiffness and adopted a gait pattern with increased knee and ankle moments, suggesting increased loading at these joints.

App-based telerehabilitation program for older adults on waiting list for physiotherapy after hospital discharge: a feasibility pragmatic randomized trial.

BACKGROUND: Inactivity while waiting for outpatient physiotherapy worsens the physical deconditioning of older adults after hospital discharge. Exercise programs can minimize the progression of deconditioning. In developing countries, telerehabilitation for older adults on the waiting list is still in the early stages. This study aimed to evaluate the feasibility of the study procedures of a telerehabilitation program for older adults waiting for outpatient physiotherapy after hospital discharge. METHODS: This pragmatic randomized controlled trial recruited older adults (≥ 60 years) with several clinical diagnoses on the waiting list for outpatient physiotherapy in the Brazilian public health system after hospital discharge. The telerehabilitation group (n = 17) received a personalized program of multicomponent remote exercises using a smartphone app. The control group (n = 17) followed the usual waiting list. We assessed recruitment and dropout rates, safety, adherence, and satisfaction. The preliminary effects were verified on clinical outcomes. RESULTS: We recruited 5.6 older adults monthly; dropouts were 12%. No serious adverse events were associated with the telerehabilitation program. The weekly adherence was 2.85 (1.43) days, and in 63.3% of the weeks the participants were enrolled, they performed the exercise program at least twice a week. Participants rated the telerehabilitation program as 9.71 (0.21), and the safety of remote exercises without professional supervision as 8.6 (2.2) on a 0-10 scale. CONCLUSIONS: The telerehabilitation program using a smartphone app was safe and presented high participants' satisfaction and adequate adherence, recruitment, and dropout rates. Therefore, the definitive study can be conducted with few modifications. TRIAL REGISTRATION: Brazilian Registry of Clinical Trials (ReBEC), RBR-9243v7. Registered on 24 August 2020. https://ensaiosclinicos.gov.br/rg/RBR-9243v7 .

Reductions in rearfoot eversion posture due to proximal muscle strengthening are dependent on foot-ankle varus alignment.

BACKGROUND: Strengthening the hip and trunk muscles may decrease foot pronation in upright standing due to expected increases in hip passive torque and lower-limb external rotation. However, considering the increased pronation caused by a more varus foot-ankle alignment, subjects with more varus may experience smaller or no postural changes after strengthening. OBJECTIVE: To investigate the effects of hip and trunk muscle strengthening on lower-limb posture during upright standing and hip passive torque of women with more and less varus alignment. METHODS: This nonrandomized controlled experimental study included 50 young, able-bodied women. The intervention group (n = 25) performed hip and trunk muscle strengthening exercises, and the control group (n = 25) maintained their usual activities. Each group was split into two subgroups: those with more and less varus alignment. Hip, shank, and rearfoot-ankle posture and hip passive external rotation torque were evaluated. Mixed analyses of variance and preplanned contrasts were used to assess prepost changes and between-group differences (α = 0.05). RESULTS: The less-varus subgroup of the intervention group had a reduced rearfoot eversion posture (P = 0.02). No significant changes were observed in the less-varus subgroup of the control group (P = 0.31). There were no significant differences in posture between the control and intervention groups when varus was not considered (P ≥ 0.06). The intervention group had increased hip passive torque (P = 0.001) compared to the control group, independent of varus alignment. CONCLUSION: Despite the increases in hip passive torque, the rearfoot eversion posture was reduced only in women with a less-varus alignment. Having more foot-ankle varus may prevent eversion reductions.

Performance in field-tests and dynamic knee valgus in soccer players psychologically ready and not ready to return to sports after ACL reconstruction.

BACKGROUND: The objective was to compare the performance in field tests, dynamic knee valgus, knee function, and kinesiophobia of soccer players who were psychologically ready and not ready to return to unrestricted training or competitions after ACL reconstruction. METHODS: Thirty-five male soccer players who had undergone primary ACL reconstruction at least 6 months were divided based on the Anterior Cruciate Ligament Return to Sport after Injury (ACL-RSI) questionnaire score into ready (≥60) and not-ready (<60) groups. The modified Illinois change of direction test (MICODT) and reactive agility test (RAT) were used to impose the demand for directional change and reactive decision-making. We assessed the frontal plane knee projection angle (FPKPA) during a single-leg squat and distance in crossover hop test (CHD). In addition, we assessed kinesiophobia through the shortened version of the Tampa Scale of Kinesiophobia (TSK-11) and knee function using the International Knee Documentation Committee Subjective Knee Form (IKDC). Independent t-tests were used to compare the groups. RESULTS: The not-ready group had lower performance on the MICODT (effect size (ES) = -1.2; p < 0.001) and RAT (ES = -1.1; p = 0.004) tests and higher FPKPA (ES = 1.5; p < 0.001). In addition, they presented lower IKDC (ES = 3.1; p < 0.001) and higher TSK-11 (ES = -3.3; p < 0.001) scores. CONCLUSIONS: Physical and psychological deficits may persist in some individuals after rehabilitation. On-field tests and dynamic knee alignment evaluation should be included in the athlete evaluation before the decision-making about clearance to sports participation, especially in athletes who perceive themselves as psychologically not ready.

A new marker cluster anchored to the iliotibial band improves tracking of hip and thigh axial rotations.

Tracking hip and thigh axial rotation has limited accuracy due to the large soft tissue artifact. We proposed a tracking-markers cluster anchored to the prominent distal part of the iliotibial band (ITB) to improve thigh tracking. We investigated if the ITB cluster improves accuracy compared with a traditionally used thigh cluster. We also compared the hip kinematics obtained with these clusters during walking and step-down. Hip and thigh kinematics were assessed during a task of active internal-external rotation with the knee extended, in which the shank rotation is a reference due to smaller soft-tissue artifact. Errors of the hip and thigh axial rotations obtained with the thigh clusters compared to the shank cluster were computed as root-mean-square errors, which were compared by paired t-tests. The angular waveforms of this task were compared using the statistical parametric mapping (SPM). Additionally, the hip waveforms in all planes obtained with the thigh clusters were compared during walking and step-down, using Coefficients of Multiple Correlation (CMC) and SPM (α = 0.05 for all analyses). The ITB cluster errors were approximately 25 % smaller than the traditional cluster error (p < 0.001). ITB cluster errors were smaller at external rotation angles while the traditional cluster error was smaller at internal rotation angles (p < 0.001), although the clusters' waveforms were not significantly different (p ≥ 0.005). During walking and step-down, both clusters provided similar hip kinematics (CMC ≥ 0.75), but differences were observed in parts of the cycles (p ≤ 0.04). The findings suggest that the ITB cluster may be used in studies focused on hip axial rotation.

Trunk, Mass Grasp, Knee, and Hip Muscle Performance in CrossFit Participants: Reference Values According to Participants' Sex and Limb Dominance.

Background: CrossFit is characterized by a diverse range of exercises recruiting different muscles and requiring different muscle functions. A characterization of muscular performance parameters in this population is needed. Purpose: To determine reference values for various aspects of muscular performance of muscles of the trunk, thigh, hip, and mass grasp in CrossFit participants. Also, this investigation aimed to compare the strength measures between male and female CrossFit participants, as well as between dominant and non-dominant limbs. Design: Descriptive, Cross-sectional. Setting: Laboratory. Methods: Isometric strength of trunk extensors (TE) and mass grasp was measured with handheld and Jamar dynamometer respectively. An isokinetic dynamometer was used to assess the muscle performance of the knee flexors (KF) and extensors (KE) (at 60º/s and 300º/s), and hip flexors (HF), extensors (HE), and abductors (HA) (60º/s and 240º/s ). Reference values for torque, work, power, fatigue, flexor:extensor ratio for the knee (hamstring:quadriceps - H:Q) and hip (HF:HE) joints were calculated. The torque and work values were normalized by the body mass. Mixed multivariate and univariate analyses of variance and independent t-tests were used for statistical analyses to compare between sexes and limbs. Results: Participants included 111 individuals (58 males and 53 females) with at least one year of experience in CrossFit. Normative data are provided for the outcome variables. Males had greater values of muscular performance parameters than females in most variables (p<0.05). Also, the dominant limb had greater mass grasp strength (p<0.002), greater KE power at 60º/s (p=0.015), lower H:Q ratio at 60º/s (p=0.021) and 300º/s (p=0.008), and lower KE fatigue (p=0.002). Conclusion: This study provides reference values for the trunk extensors, mass grasp, knee, and hip muscle performance in male and female CrossFit practitioners. Their muscle performance profile was characterized by few inter-limb asymmetries, and males demonstrated greater muscular performance outcomes than females, even after normalization by body mass. These reference values can be used for comparisons in research and clinical settings. Level of Evidence: 3b.