Non-dominant Hip Research Articles

Algorithm Validation for Quantifying ActiGraph™ Physical Activity Metrics in Individuals with Chronic Low Back Pain and Healthy Controls.

Assessing physical activity is important in the treatment of chronic conditions, including chronic low back pain (cLBP). ActiGraph™, a widely used physical activity monitor, collects raw acceleration data, and processes these data through proprietary algorithms to produce physical activity measures. The purpose of this study was to replicate ActiGraph™ algorithms in MATLAB and test the validity of this method with both healthy controls and participants with cLBP. MATLAB code was developed to replicate ActiGraph™'s activity counts and step counts algorithms, to sum the activity counts into counts per minute (CPM), and categorize each minute into activity intensity cut points. A free-living validation was performed where 24 individuals, 12 cLBP and 12 healthy, wore an ActiGraph™ GT9X on their non-dominant hip for up to seven days. The raw acceleration data were processed in both ActiLife™ (v6), ActiGraph™'s data analysis software platform, and through MATLAB (2022a). Percent errors between methods for all 24 participants, as well as separated by cLBP and healthy, were all less than 2%. ActiGraph™ algorithms were replicated and validated for both populations, based on minimal error differences between ActiLife™ and MATLAB, allowing researchers to analyze data from any accelerometer in a manner comparable to ActiLife™.

Association Between Dominant-Shoulder Internal-Rotation Restriction and Low-Back Pain in Elite Male High School Soft Tennis Players.

The incidence of low-back pain (LBP)is high among elite male high school soft tennis players. A previous report showed that hip internal-rotation (IR) restriction in the non-dominant leg could increase the risk of LBP. Moreover, IR in the dominant shoulder is important for serve and stroke movements, suggesting that IR restriction in the dominant shoulder can contribute to LBP. The simultaneous incidence of non-dominant-hip IR restriction may help in developing a good LBP-related factor model; therefore, this study aimed to investigate the association between dominant-shoulder IR restriction and LBP in elite male high school soft tennis players. This is a single-center cross-sectional study. This study included 176 male high school soft tennis players from 14 elite teams. The main measures were IR and external-rotation range of motion (ROM) in the dominant and non-dominant shoulders and hip, assessed using a goniometer with a bubble attached. Multiple logistic regression analyses were performed with the presence of LBP as a categorical variable (LBP, 1; non-LBP (NLBP), 0). Multiple logistic regression models were created as follows: Model 1 included dominant-shoulder IR restriction (loss of glenohumeral IR (GIRLoss)), Model 2 included non-dominant-hip IR ROM, and Model 3 included both GIRLoss and non-dominant-hip IR ROM as the main explanatory variables to test the association between dominant-shoulder IR restriction and LBP, compare its suitability as an associated factor with non-dominant-hip IR restriction, and determine if either or both should be considered in an LBP association model based on model fit. The significance of each multiple logistic regression model was examined using the model χ2 test, and a model with P<0.05 was judged as a significant model. Model fit was examined using the Hosmer-Lemeshow test, and P≥0.05 was judged as a good model fit. The Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC) were used to compare the goodness-of-fit among multiple logistic regression models. Results: The LBP and non-LBP groups comprised 59 and 117 players, respectively. GIRLoss in the dominant shoulder was a significant independent factor (odds ratio: 1.06, 95% CI: 1.02-1.09; P<0.01) in Model 3, which included hip IR restriction in the non-dominant leg (odds ratio: 0.90, 95% CI: 0.86-0.94; P<0.01).In all models, the explanatory variables fitted were significantly associated with LBP, indicating that the models were significant and fitted well: the AICs (and BICs) for Models 1, 2, and 3 were 198.4 (207.6), 178.6 (187.9), and 168.8 (181.1), respectively, indicating that Model 3 was the best fit. In elite male high school soft tennis players, IR restriction in the dominant shoulder was associated with LBP. IR restriction in the dominant shoulder and non-dominant hip as a significant factor for LBP may contribute to developing an optimal multiple logistic regression model for LBP.

The relationship of hip strength and dynamic knee valgus during single leg squat in physically active females

BackgroundSingle leg squat (SLS) is an important motion commonly observed in sports. Excessive dynamic knee valgus (DKV) during SLS may increase non-contact knee injury risks particularly in physically active females. As muscular strength plays crucial role in controlling DKV, the present study aims to evaluate the correlation between hip strength and knee frontal plane angle during SLS among females with and without excessive DKV. MethodsThirty-four volunteers were allocated to the valgus (n = 17) and non-valgus (n = 17) groups. Their motions during SLS at 45° and 60° knee flexion were captured and analyzed using three-dimensional motion analysis system. Isokinetic hip strength was examined at 180°/s in flexion, extension, abduction, and adduction for both legs. Pearson's correlation test was computed to evaluate the relationship between hip strength and knee angle during SLS. FindingsNon-dominant hip extensor strength (r = −0.56, p = 0.02) and dominant hip adductor strength (r = −0.51, p = 0.04) were significantly related to the knee frontal plane angle during 45° SLS among those without DKV. Meanwhile, those with DKV showed a significant relationship between the knee frontal plane angle for both legs and non-dominant hip abductor strength during 60° SLS. InterpretationBoth groups demonstrated the relationship of hip strength on knee frontal plane angle during SLS, whereby increased hip strength may minimize excessive DKV. Those with excessive DKV should train to strengthen their hip abductor to reduce knee valgus particularly during deep squats.

Influence of restricted visual input on lower limb joint works of female children during sit-to-stand

BackgroundThe ankle-knee-hip joint systems have structures that can produce mechanical work through elastic, viscoelastic mechanisms or muscle activity. This study aimed to compute sit-to-stand (STS) joint works in lower limbs between blind and sighted children to find the relationship between visual memory and STS joint work variables. MethodsThis study included fifteen female children with congenitally blind (CB) and 30 healthy girls without visual impairments. The children with no visual impairments were randomly divided into two condition groups with 15 each, the eyes open (EO) and the eyes closed (EC). Inverse dynamics calculated joint works by integrating multiple the moment and angular velocity (F1) and force and velocity (F2). They were normalized to body mass and body height. ResultsGenerally, the sensitivity of F1 (on both sides in the sagittal and frontal planes) was more than F2 (on the non-dominant side in the mediolateral and vertical axes). In the ML axis, the EC group had insufficient maximal non-dominant hip work relative to the EO group (p = 0.002). In addition, the CB group suffered from low hip efficiency (p = 0.003) and high knee (p < 0.001) mechanical work. ConclusionsNumerous differences between CB and EC groups (on knee and hip works) showed that the time of visual input deprivation could change the type of human body's strategies to reach the consolidation process and keep adequate balance during STS. Therefore, rehabilitation programs should be aimed at addressing the impairments in the management of restricted visual input during STS performance.

E040 Differences in clinical characteristics in patients with extremes of discordance in bone mineral density in the hips

Abstract Background/Aims Osteoporosis is a clinical condition which is characterised by low bone mineral density (BMD) and is associated with increased risk of fractures and subsequent increased morbidity and mortality. Usually BMD is measured at either the spine or the non-dominant hip (usually the left hip). However, our DEXA scanner routinely measures BMD at both hips and enables discordance in terms of BMD to be measured. This study aimed to ascertain whether patients with extremes of discordance in their BMD between both hips are more likely to have certain clinical characteristics and different risk for fractures. Methods Data from a dual-energy X-ray absorptiometry (DEXA) scanner in the North West of England were used. Patients who were referred between 2004-2011 were studied. Patients had both hips scanned as well as risk factors and presence of fracture recorded. Those that had a BMD T-score difference from 0 and upwards formed the positive discordance group. Those that had a BMD T-score difference of either less than or equal to -1SD formed the negative discordance group. These two groups were compared using independent sample t-tests for continuous variables and chi-squared tests for categorical variables. Logistic models were then fitted to look at the odds of fracture in each group. Results The hip BMD T-scores of 10,335 patients were measured. Mean age was 62.41 (±12.99) with 82.61% being female. The odds ratio for the measured risk factors and the association with fracture are shown in Table 1 below. Significant risk factors are highlighted Conclusion Patients that had a positive discordance had lower weight and BMI. Also, there was a higher proportion of females in the positive discordance group. These are important risk factors used in fracture risk assessment. It is possible that if BMD is only measured in one hip, patients may be misclassified as not having osteoporosis. However, if BMD is measured in both hips, discordance might be present suggesting osteoporosis in the right hip. This discordance in BMD in our study is associated with some risk factors like age and sex which may increase future fracture risk. Disclosure A. Saeed: None. M. Bukhari: None.

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

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

Risk factors associated with throwing injuries in young baseball players.

Few studies have retrospectively analyzed the relationship between joint range of motion (ROM) and muscle flexibility and shoulder and elbow throwing injuries in a large number of elementary school baseball players. The purpose of this study was to retrospectively identify the physical factors related to shoulder and elbow throwing injuries in younger baseball players. A total of 2,466 younger baseball players belonging to our Prefecture Rubber Baseball Federation who participated in medical check-ups from 2016 to 2019 were analyzed. Players completed a questionnaire and had a medical check-up that included a physical examination and ultrasonography. ROM (internal rotation (IR) angle and external rotation (ER) angle) of the shoulder and hip, and the finger-to-floor distance (FFD) and heel-to-buttock distance (HBD) were measured. The straight-leg-raise (SLR) was also performed. The results of two groups (normal group and injury group) were compared using the χ2 test, Mann-Whitney U test and Student's t-test. Stepwise forward logistic regression models were developed to identify risk factors. On univariate analysis, nine of the 13 evaluated items showed significant decreases in ROM and muscle flexibility in the injury group. On multiple logistic regression analysis, grade, FFD, IR angle of the dominant side shoulder, and IR angle of the nondominant side hip were significantly associated with the occurrence of throwing injuries. Decreased total shoulder angle was observed not only on the dominant side, but also on the nondominant side in the injured group. Decreased ROM and muscle flexibility were risk factors for baseball-related throwing injuries in elementary school baseball players. To prevent shoulder and elbow throwing injuries, players, coaches, medical staff, and parents need to be aware of these findings.

Myosteatosis and bone marrow adiposity are not associated among postmenopausal women with fragility fractures.

Although paravertebral intramuscular fatty infiltration (known as myosteatosis) following a vertebral fracture is well-known, scarce data are available regarding interactions between muscle, bone, and other fat depots. Based on a homogeneous cohort comprising postmenopausal women with or without a history of fragility fracture, we aimed to better depict the interrelationship between myosteatosis and bone marrow adiposity (BMA). 102 postmenopausal women were included, 56 of whom had a fragility fracture. Mean proton density fat fraction (PDFF) was measured in the psoas (PDFFPsoas) and paravertebral (PDFFParavertebral) muscles at the lumbar level, as well as in the lumbar spine and non-dominant hip using chemical shift encoding-based water-fat imaging. Visceral adipose tissue (VAT) and total body fat (TBF) were assessed using dual X-ray absorptiometry. Statistical models were adjusted for age, weight, height (all comparisons), and bone mineral density (when considering BMA). PDFF in the psoas and paravertebral muscles was higher in the fracture group compared to controls even after adjustment for age, weight, and height (PDFFPsoas = 17.1 ± 6.1% versus 13.5 ± 4.9%, p=0.004; PDFFParavertebral = 34.4 ± 13.6% versus 24.9 ± 8.8%, p=0.002). Higher PDFFParavertebral was associated with lower PDFF at the lumbar spine (β = -6.80 ± 2.85, p=0.022) among controls but not in the fracture group. In both groups, a significant relationship between higher PDFFPsoas and higher VAT was observed (β = 20.27 ± 9.62, p=0.040 in the fracture group, and β = 37.49 ± 8.65, p<0.001 in the control group). Although solely observed among controls, a similar relationship was observed between PDFFParavertebral and TBF (β = 6.57 ± 1.80, p<0.001). No significant association was observed between BMA and other fat depots. Myosteatosis is not associated with BMA among postmenopausal women with fragility fractures. Whereas myosteatosis was associated with other fat depots, BMA appears uniquely regulated.

P077 Bone mineral density predicts fractures when measured in more than one area: results from a large observational cohort

Abstract Background/Aims Osteoporosis is characterised by a reduction in bone mineral density (BMD). Low BMD is correlated with increased fracture risk. It is unclear whether a BMD value at a specific site is superior for predicting fracture. The Fracture Risk Assessment (FRAX™) tool is used to evaluate fracture risk, using the BMD at the non-dominant hip; focussing on the neck mean and neck total. This is despite a T score of -2.5 or below in the lumbar spine defining a patient as osteoporotic. This study aimed to determine whether the other measures of BMD that are noted are as predictive of fracture. Methods Patients referred for routine dual-energy x-ray absorptiometry (DEXA) scans at the Royal Lancaster Infirmary from 2004 to 2019 were studied. BMD data from lumbar vertebrae (L1-L4) and anatomical regions of the left and right femur were collected from DEXA images. A logistic regression model was fitted using fracture as a dependent variable and BMD values from the lumbar vertebrae, right and left femur as predictors, adjusted for age at scan and sex. Goodness of fit was assessed using a receiver operating characteristic (ROC) curve. Results A total of 31,546 patients were included in the analysis (82.9% female), of whom 37.6% had sustained a fracture, and the mean age of the cohort was 64.9 (standard deviation 12.9). Table 1 shows the results of the logistic models. Areas under the receiver operating characteristic curve (AUC) demonstrated the positive predictive ability of a reduction in BMD in the lumbar vertebrae and regions of the femur and fracture risk. BMD data from the four lumbar vertebrae were just as predictive of fracture as the right and left femur. Conclusion The study findings demonstrate that low BMD in all areas measured were equally predictive of fracture. When the non-dominant hip is not measurable, using other areas from a DEXA scan could be used to predict fracture risk. Research evaluating change in BMD over time could alter this observation. Disclosure U. Nadeem: None. M. Bukhari: None. Z. Sultan: None.

Analysis of the adductors and abductors' maximum isometric strength on the level of speed and agility in basketball players

Introduction: his study investigated the relationship between hip abductor strength (Abd), adductor strength (Add), straight accelerations and decelerations, and during changes of direction (COD 90°) performance in basketball players. Material and Methods: Fourteen basketball players participated (age = 23.6 ± 4.4 years, body mass = 86.3 ± 5.9 kg, body height = 192.3 ± 6.2 cm, training experience = 6.7 ± 2.6 years). Straight running results and running with a change of direction (COD 90°) have been described as the time (s) obtained for a given length. Following tests were carried out: maximum isometric strength test, 20-m linear sprint and 20-m COD sprint with 90° direction change angles. Following the warm-up, all athletes performed two maximal 20-m linear sprints, interspersed with 5 min rest intervals. Following the 20-m linear sprint test, the participants were provided with a 5 min rest interval before completing the COD tests. Additionally, the balance in isometric strength of the dominant and non-dominant hip Abd-Add muscles were evaluated. Two maximum attempts interspersed with one-minute rest intervals were performed. Results: The t-test revealed statistically significant higher absolute and relative isometric strength of AddR (adductor right) in comparison to AddL (adductor left). Conclusion: The results of this study show that the maximum isometric force and the relative strength of the abductor muscle group have a significant effect on changing direction running. Moreover, hip Abd and Add are typical for strength bilateral strength imbalances. Therefore, the evaluation and development of these qualities are essential for coaches to monitor and prescribe adequate training regimens.

Association Between Nondominant Leg-Side Hip Internal Rotation Restriction and Low Back Pain in Male Elite High School Soft Tennis Players.

The incidence of low back pain (LBP) is high among high school male soft tennis players. In some sports for which the rotational component of the body is important, an association between restricted hip internal rotation of the nondominant leg and LBP has been reported; however, whether this association holds in soft tennis is unknown. Therefore, this study aimed to evaluate the association between hip internal rotation, hip external rotation, hamstring flexibility, iliopsoas flexibility, and LBP incidence. This study was designed as a cross-sectional study, conducted at a sports training center. Participants comprised 113 male elite high school soft tennis players (age: 16.1 [0.7]y) from 9 elite-level teams. The main outcome measures were the hip internal and external rotation range of motion, hamstring flexibility on the straight leg raise test, and iliopsoas flexibility on the Thomas test. Multiple logistic regression analysis was performed to examine the influence of main outcomes on LBP incidence in the past 1year. A total of 35 participants had LBP (LBP group); 78 participants did not have LBP (non-LBP group). Multiple logistic regression analysis revealed that the odds ratio for height was 1.08 (95% confidence interval, 1.00-1.16; P = .043) and for the hip internal rotation range of motion in the nondominant leg was 0.90 (95% confidence interval, 0.85-0.95; P < .001), indicating significant associations with LBP. Hip internal rotation range of motion in the nondominant leg and height were crucial factors related to LBP in male elite high school soft tennis players.

Calibration of hip accelerometers for measuring physical activity and sedentary behaviours in adults with Down syndrome.

The knowledge base on physical activity and sedentary behaviour in adults with Down syndrome (DS) may advance by accelerometer calibration studies. This study aimed to develop cut-points for sedentary behaviour and moderate-to-vigorous physical activity (MVPA) for adults with DS based on output from accelerometers worn on the dominant and non-dominant hips. Sixteen adults with DS (10 men; age 31±15years) performed 12 tasks including sedentary behaviours and physical activities. We obtained metabolic equivalents (METs) with indirect calorimetry and vector magnitude (VM) output from triaxial accelerometers (wGT3X-BT, ActiGraph) worn on the dominant and non-dominant hips. Receiver operating characteristic curves were used to identify optimal VM cut-points that maximised sensitivity and specificity. Overall classification accuracy was very high (area under the ROC curve: 0.95 and 0.92 for sedentary and MVPA models, respectively). For the non-dominant hip, the optimal VM cut-points were (1) sedentary behaviour ≤236 counts·min-1 and (2) MVPA ≥2167 counts·min-1 . For the dominant hip, optimal cut-points were (1) sedentary behaviour ≤243 counts·min-1 and (2) MVPA ≥2092 counts·min-1 . The presented VM cut-points for sedentary behaviour and MVPA for adults with DS had high classification accuracy. There were small differences in accelerometer cut-points between the dominant and non-dominant hip.

Phenotypes of body composition in patients with systemic sclerosis

Background. Systemic sclerosis (SSc) is an autoimmune inflammatory disease of connective tissue with a polysyndromic clinical picture. One of the factors that significantly affect the quality of life of such patients is the involvement of the musculoskeletal system. A small number of studies were aimed at studying osteoporosis and body composition in patients with SSc, however, the clinical heterogeneity of the disease, a small number of patients included in the studies do not allow to draw unambiguous conclusions about the frequency of various phenotypes of body composition, their relationship and factors affecting their occurrence.Aim. To study the body composition and to establish the frequency of isolated and combined pathological phenotypes in women with SSс and to determine the factors associated with the muscle mass.Materials and methods. 85 postmenopausal women (46 with SSc, 39 without rheumatic pathology) were included. Questionnaires, anthropometric measurements, assessment of nutritional status by MNA, dual-energy X-ray absorptiometry of the whole body, lumbar spine, femoral neck and total hip were carried out. Correlation and univariate linear regression analyses were performed to identify factors related to appendicular muscle mass.Results. Normal body composition was found in 13.0% of patients with SSс and 25.6% — in the control, isolated and combined pathological phenotypes were detected in 34.8% and 52.2% women with SSс and in 61.5% and 12.8% in the group without rheumatic diseases, respectively. Combined pathological phenotypes, phenotypes with the presence of sarcopenia and/or osteoporosis were significantly more often in SSc patients (p&lt; 0.001), but the frequency of obesity did not differ (69.6% and 64.1%, respectively). Negative correlations were revealed between the value of appendicular muscle mass and the presence of osteolysis of the nail phalanges (Rs=-0.23), the cumulative dose of glucocorticoids (GC) (Rs=-0.43) and direct — with the value of the femoral neck BMD (Rs=0.47), nutritional status by MNA (Rs=0.51), BMI (Rs=0.70), the circumference of the shoulder of the non-dominant arm (Rs=0.68), waist (Rs=0.66), hips (Rs=0.72) and lower leg of the non-dominant leg (Rs=0.81), p&lt; 0.05. Univariate linear analysis confirmed the presence of positive associations between the appendicular muscle mass and proximal hip BMD, BMI, shoulder circumferences, waist, hips and lower leg (p&lt; 0.001), and negative associations with the Rodnan skin score (p=0.012) and the cumulative dose of GC (p=0.001).Conclusion. 87% of patients with SSc had pathological phenotypes of body composition, among them combined phenotypes were significantly more common than in people without rheumatic diseases. BMD in the proximal hip, BMI, circumference of the shoulder, waist, hips and lower leg were positively, and the Rodnan skin score and cumulative dose of GC were negatively associated with the appendicular muscle mass.

Does physical activity timing differentially correlate with symptoms of restless legs syndrome in adults with multiple sclerosis?

Objective/backgroundThe present study examined the associations among physical activity during different times of the day(i.e., morning, midday,evening) and days of the week(i.e., weekdays, weekend days) with restless legs syndrome(RLS) severity and sleep quality in adults with multiple sclerosis(MS). Patients/methodsParticipants(N = 39) completed the International Restless Legs Syndrome Study Group Scale and the Pittsburgh Sleep Quality Index as measures of RLS severity and global sleep quality, respectively, and wore an ActiGraph GT3X + on the non-dominant hip for seven days for measuring physical activity(i.e., light physical activity[LPA], moderate-to-vigorous physical activity[MVPA], and steps). ResultsThere was a significant effect of time of day wherein participants had more midday activity compared with morning or evening for LPA, MVPA, and steps; there was no effect of day of the week. Spearman's rho correlations across the week indicated higher evening LPA, evening steps, and overall daily steps (ρ = −0.42,ρ = −0.51,ρ = −0.40,respectively) were associated with lower RLS severity. Similar associations were demonstrated for weekdays(ρ = −0.39,ρ = −0.50,ρ = −0.41,respectively) and weekend days(ρ = −0.44,ρ = −0.51,ρ = −0.39,respectively). Higher evening MVPA on weekend days(ρ = −0.42) was associated with lower RLS severity. Higher morning and overall daily LPA(ρ = 0.34,ρ = 0.33,respecitvely) were associated with worse sleep quality. Similar associations were demonstrated on weekdays(ρ = 0.33,ρ = 0.37,respectively) and more evening MVPA(ρ = 0.32) was associated with worse sleep quality. On weekend days, more morning MVPA(ρ = 0.42) was associated with worse sleep quality. ConclusionsOur results suggest that undertaking physical activity, particularly LPA and steps, in evenings may be important for managing symptoms of RLS without worsening sleep quality.

253 Physical activity patterns in adolescents and young adults with intellectual and developmental disabilities

OBJECTIVES/GOALS: Individuals with intellectual and developmental disabilities (IDD) have lower levels of moderate-to-vigorous physical activity (MVPA) and a greater risk for sedentary-related comorbidities compared to their typically developing peers. Understanding activity patterns may provide opportunities for targeted physical activity interventions. METHODS/STUDY POPULATION: Secondary analyses were performed on baseline accelerometer data pooled from 2 clinical trials and a pilot study in adolescents (11-17 years) and young adults (18-21 years) with IDD. MVPA was assessed using accelerometers worn on the non-dominant hip during waking hours over 7 consecutive days. Data were collected at 60 hertz and activity counts were aggregated over 60 second epochs. Wear time was determined with the Choi algorithm and MVPA was classified using the Troiano adult or Freedson age-specific child cut-points. Mixed effects linear regressions were used to determine the effects of day of the week, time of the day, and season on MVPA. Diagnosis, gender, and age were used as fixed effect covariates with random intercepts varying among the participants and days of observation within each participant. RESULTS/ANTICIPATED RESULTS: There were 231 individuals (15.6 ± 2.8 years, 51.5% female) who had IDD (36.8% Autism, 48.1% Down syndrome) with 22,498 minutes of MVPA. Individuals with IDD wore the accelerometers an average of 592 ± 254 min./day and completed 13.5 ± 17.9 min./day of MVPA. Average MVPA was lowest in individuals with Autism (12.6 ± 11.4 min./day) and Down syndrome (13.2 ± 9.3 min./day) when compared to those with other IDDs (16.8 ± 10.8 min./day). Participation in MVPA was similar in males (13.4 ± 10.7 min./day) and females (13.7 ± 9.9 min./day). Mixed effects linear regressions showed that individuals participated in fewer minutes of MVPA on the weekend (β = -0.75, p &lt; 0.001) and from 12-3 pm (reference) when compared to before 12 pm (β = 0.87, p &lt; 0.001) and 3-7 pm (β = 0.66, p=0.007). No significant seasonal effects were found. DISCUSSION/SIGNIFICANCE: Individuals with IDD were significantly less active on the weekend, but they did participate in more minutes of MVPA in the morning and late afternoon/early evening. Physical activity interventions aiming to increase MVPA on the weekend and during the early afternoon may increase the number of weekly minutes of MVPA in individuals with IDD.

Automatic Markerless Motion Detector Method against Traditional Digitisation for 3-Dimensional Movement Kinematic Analysis of Ball Kicking in Soccer Field Context.

Kicking is a fundamental skill in soccer that often contributes to match outcomes. Lower limb movement features (e.g., joint position and velocity) are determinants of kick performance. However, obtaining kicking kinematics under field conditions generally requires time-consuming manual tracking. The current study aimed to compare a contemporary markerless automatic motion estimation algorithm (OpenPose) with manual digitisation (DVIDEOW software) in obtaining on-field kicking kinematic parameters. An experimental dataset of under-17 players from all outfield positions was used. Kick attempts were performed in an official pitch against a goalkeeper. Four digital video cameras were used to record full-body motion during support and ball contact phases of each kick. Three-dimensional positions of hip, knee, ankle, toe and foot centre-of-mass (CMfoot) generally showed no significant differences when computed by automatic as compared to manual tracking (whole kicking movement cycle), while only z-coordinates of knee and calcaneus markers at specific points differed between methods. The resulting time-series matrices of positions (r2 = 0.94) and velocity signals (r2 = 0.68) were largely associated (all p < 0.01). The mean absolute error of OpenPose motion tracking was 3.49 cm for determining positions (ranging from 2.78 cm (CMfoot) to 4.13 cm (dominant hip)) and 1.29 m/s for calculating joint velocity (0.95 m/s (knee) to 1.50 m/s (non-dominant hip)) as compared to reference measures by manual digitisation. Angular range-of-motion showed significant correlations between methods for the ankle (r = 0.59, p < 0.01, large) and knee joint displacements (r = 0.84, p < 0.001, very large) but not in the hip (r = 0.04, p = 0.85, unclear). Markerless motion tracking (OpenPose) can help to successfully obtain some lower limb position, velocity, and joint angular outputs during kicks performed in a naturally occurring environment.

Physical Activity and Sedentary Behavior Timing in Fatigued and Nonfatigued Adults With Multiple Sclerosis

ObjectiveTo examine device-measured physical activity levels and sedentary behavior participation during different times of the day (ie, morning, midday, and evening) in adults with multiple sclerosis (MS) who differed in fatigue status. DesignCross-sectional survey. SettingRemote survey study managed by a university-based research laboratory. ParticipantsA population-based sample of 1000 participants with MS were sent recruitment materials by the North American Research Committee on Multiple Sclerosis and 218 participants completed all relevant outcomes (N=218). InterventionsNot applicable. Main Outcome MeasuresParticipants (N=218) completed the Fatigue Severity Scale (FSS) as a measure of fatigue severity and were divided into subgroups of fatigued (FSS score ≥4) and nonfatigued (FSS score <4). Participants wore an ActiGraph GT3X+ on the nondominant hip for 7 days to measure physical activity (ie, light physical activity [LPA], moderate-to-vigorous physical activity [MVPA], steps) and sedentary behavior. ResultsFatigued participants engaged in less MVPA (F[1216]=18.5, P<.001), fewer steps (F[1216]=27.8, P<.001), and more sedentary time (F[1216]=8.2, P=.005) than nonfatigued participants. Regardless of group, the highest levels of LPA (F[1.7355.7]=72.9, P<.001) and MVPA (F[1.8395.3]=23.0,P<.001) occurred in the morning and middle of the day, with the lowest levels in the evening. Regardless of group, the highest levels of sedentary behavior occurred in the evening, with similar levels in the morning and evening (F[1.6354.5]=84.3,P<.001). Regardless of group, participants had more steps in the middle of the day, followed by morning and then evening (F[1.8383.9]=84.7,P<.001). ConclusionsOur results suggest that physical activity timing should be considered in future development and delivery of behavior interventions that focus on increasing physical activity and reducing sedentary behavior among adults with MS who have fatigue.

Hip Flexibility and Dynamic Balance Ability in Soccer Players with Functional Ankle Instability

The prevention of recurrent ankle sprain and functional ankle instability in soccer players is essential. This study clarified hip joint mobility and dynamic balance ability in soccer players with functional ankle instability. This case–control study included 17 male college soccer players. All participants were assessed using the Cumberland Ankle Instability Tool and were divided into chronic ankle instability (CAI) and non-CAI groups for each of their dominant and nondominant legs. Bilateral passive hip range of motion (ROM) was assessed and the modified Star Excursion Balance Test (mSEBT) was measured for each leg. In the dominant leg, the reach in the posterolateral direction in the CAI group was significantly less than that in the non-CAI group. Hip internal rotation angles in the dominant leg in the CAI group were greater than those in the non-CAI group; however, no significant correlations with the three directions of mSEBT were observed. In the nondominant leg, mSEBT and hip ROMs did not show any significant differences between groups. The dominant leg in soccer players with CAI had poor dynamic balance ability while reaching posterolaterally. However, acquiring hip flexibility may not be necessary to improve the dynamic balance ability. These findings may help develop future research.

Shoulder and Hip Range of Motion and Strength Changes Throughout a Season in College Softball Players.

BackgroundMany studies have been done on the strength and mobility of the shoulder and hip in baseball players, but fewer studies have examined these metrics in softball players.PurposeThe purpose of this study was to observe and analyze changes in range of motion (ROM) and strength at the hip and shoulder that occur over the course of a competitive season, to describe preseason ROM and strength at the hip and shoulder in healthy college softball players through side-to-side comparison, and to compare measurements between pitchers and position players.Study DesignDescriptive Cohort StudyMethodsData was collected over the course of six seasons, and a total of fifty-four healthy softball athletes (including pitchers and postiion players) who completed at least one set of preseason and postseason measurements were included. Subjects underwent passive ROM (External rotation [ER], internal rotation [IR], total arc of motion [TAM]) and strength (ER/IR at the shoulder, abduction/extension at the hip) measurements at preseason and postseason timepoints.ResultsOver a season, position players demonstrated an increase in all ROM metrics in both shoulders, except dominant IR, and a decrease in ER strength at the shoulder bilaterally (p<0.05). They also showed decreased ROM in all metrics across both hips (p<0.05). Pitchers had increased IR and TAM ROM in the dominant shoulder, decreased strength in both shoulders (ER throwing; ER and IR non-throwing), decreased ROM in both hips, and decreased abduction strength in the non-dominant hip (p<0.05). Position players showed less preseason IR in the dominant shoulder compared to non-dominant IR (Dominant: 31.7 ± 1.6°, Non-dominant: 37.0 ± 2.3°; p<0.05).ConclusionSoftball pitchers and position players both show increased ROM at the shoulder and decreased ROM at the hip over the course of a season. Position players demonstrated side-to-side discrepancies and seasonal changes at the throwing shoulder similar to those seen in baseball players. The preseason mobility of the dominant shoulder of pitchers increased over the season while strength of hip abduction in the non-dominant side was reduced.Level of Evidence3

A comparison of accelerometer cut-points for measuring physical activity and sedentary time in adolescents with Down syndrome

BackgroundNo cut-points have been developed for youth with Down syndrome; there is concern that altered gait patterns, decreased energy expenditure and exercise capacity of individuals with Down syndrome may produce inaccurate physical activity data if accelerometer data are analyzed using cut-points from populations with typical development and other IDD diagnoses. AimTo compare physical activity and sedentary time across existing accelerometer cut-point methods in adolescents with Down syndrome. MethodsIn this cross-sectional analysis, participants diagnosed with Down syndrome (n = 37; 15.5 ± 1.9 years; 57 % female) wore an accelerometer on their non-dominant hip for seven-days. Data were analyzed and compared across four physical activity intensity cut-points: Evenson, Freedson 4-MET, McGarty, and Romanizi. Outcomes & resultsDifferences in time spent in each intensity across cut-point methods were evident for sedentary (448−615 min/day), light (72−303 min/day) and moderate-to-vigorous (12−77 min/day) activities. Between 0.0–67.6 % of the sample met the physical activity guidelines, depending on the cut-point method selected. Conclusions & implicationsThis study presents the wide variation of accumulated physical activity minutes when different cut-points are applied to individuals with Down syndrome. There is a critical need to establish Down syndrome-specific measures of physical activity assessment rather than applying methods developed for their peers with typical development. What this paper addsThis paper highlights concerns over the application of objective measurements of physical activity in youth with Down syndrome from measurement methods derived from populations with typical development. This is the first manuscript to examine this issue in a sample comprised solely of youth with Down syndrome. Results demonstrate the large variation in time spent in each activity intensity that arise due to the application of different cut-point methods.