Hip Internal Rotation Range Of Motion Research Articles

Greater hip internal rotation range of motion is associated with increased dynamic knee valgus during jump landing, both before and after fatigue.

The aim of this study was to analyse sex-specific differences contributing to dynamic valgus in competitive soccer players before and after a standardised fatiguing protocol. Thirty-nine healthy female and male competitive soccer players (19 females and 20 males) were recruited for the purpose of this study. Bilateral medial knee displacement (MKD) was assessed during drop jump landings using a three-dimensional motion capture system before and after a standardised fatiguing protocol. In addition, all soccer players underwent clinical examinations, including rotational hip range of motion (ROM), isokinetic strength testing and magnetic resonance imaging (MRI) of the hip and knee. Sex-specific and fatigue-dependent differences were reported, and the influence of demographic, clinical and radiographic factors on MKD was analysed via multiple linear regression models. Compared with male soccer players, female soccer players demonstrated a tendency towards increased MKD during drop jump landings before (p = 0.09) and after the fatiguing protocol (p = 0.04). Sex-specific differences included increased hip internal rotation (IR) ROM, decreased hip external rotation (ER) strength and increased femoral torsion in females (all p < 0.002). According to the multiple linear regression models (stepwise method), increased hip IR ROM (90° of flexion) and the non-dominant leg remained the sole independent predictors of increased MKD during drop jump landings before (p < 0.01 and p = 0.02, respectively) and after fatigue (p < 0.01 and p < 0.01, respectively). An increase in hip IR ROM in females was linearly related to MKD after fatigue (R2 = 0.25; p < 0.01). Female soccer players exhibited increased dynamic valgus before and after fatigue, which is likely attributed to joint mobility, as well as muscular and anatomical differences, such as increased hip IR ROM, reduced hip ER strength and increased femoral torsion. In particular, females with increased hip IR ROM were more susceptible to effects of fatigue on MKD, which may increase their risk for anterior cruciate ligament injury. Level III.

Golfers' Performance Is Improved More by Combining Foam Rolling and Dynamic Stretch to the Lead Hip Than Practice Golf Swinging.

Hamada, Y, Akasaka, K, Otsudo, T, Sawada, Y, Hattori, H, Kikuchi, Y, and Hall, T. Golfers' performance is improved more by combining foam rolling and dynamic stretch to the lead hip than practice golf swinging. J Strength Cond Res 38(7): e391-e397, 2024-Warming up is considered effective in improving performance and preventing injury. Despite this, there have been few studies investigating warm-up programs in golf and whether specific factors contribute to improved performance. The purpose of this study was to examine the immediate effects of combined foam rolling and dynamic stretch (FR + DS) to the lead hip on golf swing performance, hip range of motion (ROM), and muscle strength in amateur golfers using a randomized crossover design. The study sample comprised 22 men (mean ± SD ; age, 32.6 ± 8.5 years, body mass index (BMI), 23.4 ± 2.7 kg·m -2 ). Subjects were assigned to receive either FR + DS or repetitive golf swing practice (SW) before crossing over to the other intervention for another day. Measurements included golf swing performance (ball speed, club head speed, flight distance ["carry"], spin rate, and launch angle), hip internal rotation (IR), and external rotation (ER) ROM, as well as hip IR and ER muscle strength. Comparisons between groups were made before and after each intervention. For golf swing performance, FR + DS improved "carry" significantly more than SW ( p < 0.05). No significant differences in golf swing performance other than "carry" were found. In addition, IR ROM and IR muscle strength of the lead hip were significantly increased in the FR + DS group ( p < 0.05). FR + DS has effects on improving lead hip IR ROM and IR muscle strength, which may facilitate golfers' swing and "carry." FR + DS shows promise as a warm-up method for amateur golfers who want to improve golf performance.

Foot posture index and hip joint rotation mobility in handball and soccer players

Purpose: To assess the foot posture and hip joint mobility of elite handball and soccer players and to investigate possible correlations between these measurements. Methods: We compared the differences in means of Foot Posture Index (FPI), passive hip internal (IR), and external (ER) rotation range of motion (ROM) between three groups of male subjects (17 handball players, 17 soccer players, and 16 non-athletes). The Kruskal-Walli’s test and post-hoc pairwise comparison with the Mann-Whitney U test were used to determine the differences between the group means, and associations between variables were analyzed with Spearman’s correlation coefficient. Results: No significant differences in the mean FPI were found between the soccer players (1.3 ± 2.9), handball players (0.7 ± 2.1), and the control group (1.7 ± 2.5) (p &gt; 0.05). Similarly, no significant difference was found between the groups in the hip ER ROM. In contrast, a significantly lower (p &lt; 0.05) hip IR ROM was observed in the soccer players (30.6° ± 5.3°) compared to the handball players (41.0° ± 8.1°) and the control group (41.1° ± 6.4°). A weak positive correlation was only observed between the FPI and hip IR ROM in the soccer players (ρ: 0.36, p = 0.035). Conclusions: Handball and soccer players show a tendency toward less pronated feet compared to non-athletes, but the differences are not significant and the mean FPI values are still within the range of normal foot posture. The range of hip IR seems to be reduced in soccer players and weakly, but significantly and positively associated with the FPI value, which needs to be further investigated in future studies.

Ankle dorsiflexion range of motion and hip abductor strength can predict Lower Quarter Y-Balance Test performance in healthy males

ObjectivesThe aim of the study was to assess whether strength and range of motion (ROM) of the hip and ankle are the factors determining performance in the Lower Quarter Y-Balance test (YBT-LQ). DesignCross-sectional study. Participants66 healthy males (age: 25.2±6.8 years) participated in this study. Main outcome measuresParticipants underwent assessments of ankle dorsiflexion (DF) ROM, hip internal rotation (IR) ROM, external rotation (ER) ROM and isometric strength of hip abductor (ABD), extensor (EXT) and external rotators (ERS) muscles together with YBT-LQ for both legs. A forward 2-steps multiple linear regression analysis was conducted to examine the relationship between the predictor variables and the criterion variable. ResultsAnkle DF ROM predicted anterior (ANT) reach (R2 = 0.49; R2 = 0.33; p < 0.001). The model with hip ABD strength and ankle DF ROM explained posteromedial (PM) reach variance for stance leg (R2 = 0.35; p < 0.001), while only hip ABD strength was included for kicking leg (R2 = 0.19; p = 0.007). The model with ankle DF ROM and hip ABD strength explained posterolateral (PL) reach for stance leg (R2 = 0.41; p < 0.001). Hip ABD was the only predictor for kicking leg PL reach (R2 = 0.15; p < 0.001). YBT-LQ composite score was explained by ankle DF ROM and hip ABD strength for both legs (R2 = 0.44; p < 0.001) and (R2 = 0.25; p = 0.002). ConclusionHip ABD strength and ankle DF ROM can determine performance in the YBT-LQ. Strength of hip EXT, ERS as well as ROM of hip IR and ER did not predict YBT-LQ performance.

The Biomechanical and Functional Status of Patients with Knee Osteoarthritis - A Cross Sectional Study

Background and Objectives: Knee deformity associated with osteoarthritis (OA) is one of the most common complications reported to orthopaedic surgeons. Genu valgum and genu varum are the most commonly occurring deformities due to knee osteoarthritis. When there is progression in degeneration due to osteoarthritis, deformities tend to worsen and will eventually lead to reduction in cadence rate, hindfoot angle, range of motion in both hip and knee. Thus, this study is conducted to analyze these parameters like cadence, hindfoot angle, hip internal flexion, knee flexion, WOMAC scale and VAS pain rating scale between the groups of individuals with genu valgum and genu varum deformity. Methodology: A convenient division was made of a total of 80 knee osteoarthritis (OA) patients into two groups by measuring their medial tibiofemoral angle, namely genu valgum and genu varum. The patients were evaluated for various parameters including gait cadence, reduced knee flexion, hip internal rotation, hind foot angle, WOMAC scale, and VAS pain scale. The discrepancies in these parameters were analyzed between the genu valgum and genu varum groups. This study design represents a cross-sectional approach. Results: The Independent t-test was used to examine the results among the groups, with a significance level set at p ≤ 0.05. Considerable statistical changes were observed in cadence, hindfoot angle, knee flexion ROM, and hip internal rotation ROM, with corresponding p-values of 0.0006, 0.049, 0.002, and 0.01, respectively. However, no significant differences were found in the case of the WOMAC scale and VAS pain rating scale between the groups with genu valgum and genu varum deformities, as their p-values were considerably higher than the significance level (0.169, 0.948). Conclusion: The objective of the study was to gain insight into the biomechanical and functional condition of individuals suffering from knee osteoarthritis. Substantial differences were observed between the groups regarding cadence, hindfoot angle, knee flexion range of motion (ROM), and hip internal rotation ROM. However, when evaluating the WOMAC scale and VAS pain rating scale, both groups exhibited nearly identical values, indicating a lack of statistical significance in these outcome measures. Keywords: Knee osteoarthritis, genu valgum, genu varum, tibiofemoral angle, cadence, hindfoot angle, knee flexion ROM, hip internal rotation ROM, WOMAC scale, VAS scale.

The COVID-19 lockdown as a model of detraining in division 1 college softball players

BackgroundThe COVID-19 pandemic interrupted the organized training of softball players, similar to the abrupt cessation of sports participation that can happen after an injury. Thus, the COVID-19 pandemic offers a unique model to study how sudden detraining influences softball players.MethodsWe recruited a sample of convenience of National Collegiate Athletic Association Division 1 softball players. They participated in three data collections: pre-lockdown (Jan 2020, T1), post-lockdown (Sept 2020, T2), and before the 2021 season (Jan 2021, T3). Between T1 and T2, players received an at-home conditioning and throwing program, but compliance was not strictly monitored. Between T2-T3, players resumed formal fall training (team-organized workouts, on-field practice, and within-team scrimmage games). At each time point, we collected bilaterally: 1) shoulder internal rotation (IR) and external rotation (ER) range of motion (ROM); 2) shoulder IR and ER strength; 3) hip IR and ER ROM; and 4) hip abduction and extension strength. We used four independent (2 Sides × 3 Timepoints) MANOVA with repeated measures; we followed up significant MANOVA main effect of time with Sidak posthoc tests for pairwise comparisons between time points.ResultsFifteen players participated in this study. We found a significant MANOVA main effect of time for shoulder and hip ROM (p < 0.01). Between T1-T2, dominant shoulder ER ROM decreased 6.5°, dominant shoulder IR ROM increased 4.3°, and lead hip IR ROM increased 4.4°. Between T2-T3, dominant shoulder ER ROM increased 6.3° and trail hip ER ROM increased 5.9°. We found a significant MANOVA main effect of time for shoulder strength (p = 0.03) but not for hip strength (p = 0.18). Between T2-T3, non-dominant shoulder IR and ER increased 1.8 kg and 1.5 kg, respectively.ConclusionA sudden and prolonged cessation of organized training generated changes in shoulder and hip ROM but affected strength to a lesser extent. The loss of shoulder ER and increased lead hip IR ROM are maladaptive as they are associated with injury in overhead athletes. Resuming team-organized training and scrimmage reversed some (shoulder ER), but not all of these changes. Practitioners should monitor clinical variables regularly and be aware of potential changes due to unexpected and prolonged interruptions in training, such as when players suffer sports-related injuries.

The Biomechanical and Functional Status of Patients with Knee Osteoarthritis - A Cross Sectional Study

Background and Objectives: Knee deformity associated with osteoarthritis (OA) is one of the most common complications reported to orthopaedic surgeons. Genu valgum and genu varum are the most commonly occurring deformities due to knee osteoarthritis. When there is progression in degeneration due to osteoarthritis, deformities tend to worsen and will eventually lead to reduction in cadence rate, hindfoot angle, range of motion in both hip and knee. Thus, this study is conducted to analyze these parameters like cadence, hindfoot angle, hip internal flexion, knee flexion, WOMAC scale and VAS pain rating scale between the groups of individuals with Genu valgum and genu varum deformity. Methodology: A convenient division was made of a total of 80 knee osteoarthritis (OA) patients into two groups by measuring their medial tibiofemoral angle, namely Genu valgum and genu varum. The patients were evaluated for various parameters including gait cadence, reduced knee flexion, hip internal rotation, hind foot angle, WOMAC scale, and VAS pain scale. The discrepancies in these parameters were analyzed between the Genu valgum and genu varum groups. This study design represents a cross-sectional approach. Results: The Independent t-test was used to examine the results among the groups, with a significance level set at p ≤ 0.05. Considerable statistical changes were observed in cadence, hindfoot angle, knee flexion ROM, and hip internal rotation ROM, with corresponding p-values of 0.0006, 0.049, 0.002, and 0.01, respectively. However, no significant differences were found in the case of the WOMAC scale and VAS pain rating scale between the groups with Genu valgum and genu varum deformities, as their p-values were considerably higher than the significance level (0.169, 0.948). Conclusion: The objective of the study was to gain insight into the biomechanical and functional condition of individuals suffering from knee osteoarthritis. Substantial differences were observed between the groups regarding cadence, hindfoot angle, knee flexion range of motion (ROM), and hip internal rotation ROM. However, when evaluating the WOMAC scale and VAS pain rating scale, both groups exhibited nearly identical values, indicating a lack of statistical significance in these outcome measures.

Hip Muscle Strength, Range of Motion, and Functional Performance in Young Elite Male Australian Football Players.

Hip and groin injuries are common in field sports such as football, with measurement of hip strength and range of motion (ROM) recommended for assessment of these conditions. We aimed to report hip strength, hip ROM, and functional task performance in young elite Australian football athletes. Cross-sectional study. Fifty-eight newly drafted Australian Football League athletes completed hip abduction, adduction, internal rotation, external rotation, and flexion strength testing with an adjustable stabilized or hand-held dynamometer. Hip internal rotation and external rotation, bent knee fall out, and ankle dorsiflexion ROM were also measured. Players completed hop for distance, side bridge, and star excursion balance functional tests. We compared findings between the dominant and nondominant limbs. We found small deficits unlikely to be clinically meaningful in the dominant limb for hip abduction and adduction strength, and a small deficit in the nondominant limb for external rotation strength and side bridge time. Athletes had lower hip internal rotation (mean difference 2.56°; 95% confidence interval, 0.87 to 4.26) and total rotation ROM (2.03°; 95% confidence interval, 0.06 to 4.01) on the dominant limb. There were no meaningful differences between dominant and nondominant limbs for hip strength, ROM, or functional tests. Our results may be used for benchmarking young male Australian football athletes when targeting optimal strength and returning from injury.

Range of Motion Adaptations During a Simulated Game Exposure in Softball Pitchers.

Hip and shoulder range of motion (ROM) alterations are correlated with increased risk of injury in softball athletes. The purpose of this study was to investigate bilateral shoulder and hip ROM adaptation during a simulated softball double-header exposure. It was hypothesized that shoulder and hip ROM would decrease after simulated game exposure and would not return to baseline following a 30-minute break. Thirty (14.8±1.9 yrs, 162.5±18.3 cm, 71.79±16.03 kg) adolescent softball pitchers participated. Testing included: bilateral hip and shoulder ROM (preSG), simulated game exposure (100 pitches), bilateral hip and shoulder ROM (postSG), 30-minute break, bilateral hip and shoulder ROM (preDH), pitching first inning of a simulated double header (12 pitches), and bilateral hip and shoulder ROM (postDH). Two separate repeated measures multivariate analyses of variance tests determined differences in ROM between time points. Dominant shoulder internal rotation ROM and non-dominant shoulder internal and external rotation ROM significantly decreased from preDG. Stride hip external rotation ROM and drive hip internal and external rotation ROM significantly decreased from preSG to preDH. Key results revealed the break given between games may not be sufficient recovery time for hip ROM. Thus, assessing ROM as workload progresses can be a useful strategy for monitoring a softball pitcher's injury risk.

Immediate Effects of Foam Roller and Stretching to the Lead Hip on Golfers Swing: A Randomized Crossover Trial.

Golfers with decreased range of motion (ROM) of their leading hip internal rotation (IR) have increased lumbar rotation ROM and load. This study investigated the effects of foam roller (FR) applied to their leading hip muscles combined with stretching to the leading hip together with lumbar rotation ROM during the golf swing. The study design was a crossover design. Subjects were allocated to one of two groups comprising FR and dynamic stretching (FR + DS) or practice swing. Motion analysis was used to evaluate hip and lumbar angles during the golf swing. Data were compared using analysis of variance with Bonferroni correction using paired t-test's post hoc. The association between lead hip IR angle and lumbar spine left rotation (Lrot) angle was investigated using correlation analysis. Lead hip IR ROM during the golf swing was significantly greater in the FR + DS group (p = 0.034). The FR + DS group showed a moderate negative correlation between lead hip IR ROM and lower lumbar spine Lrot ROM during the golf swing (r = -0.522). The application of FR + DS might be useful to increase lead hip IR angle during the golf swing. Moreover, the application of FR + DS improves lead hip IR angle and may decrease lumbar spine rotation.

Poster 214: The Effect of Femoral Retroversion on Hip Range of Motion – A 3D Computational Analysis

Objectives: A subset of patients undergoing hip arthroscopy suffers from persistent pain and dysfunction which can be secondary to a number of factors. Femoral rotational deformities are often overlooked and/or providers are unsure when to address femoral deformities. Currently, there is limited to no data guiding surgeons when to consider a femoral osteotomy at the time of hip arthroscopy for FAI. Through previously validated computer-assisted 3D modeling software, this study sought to answer two questions: 1) How much femoral retroversion is too much to render cam femoroplasty ineffective in improving range of motion (ROM)? 2) In the setting of an osteotomy, what degree of femoral version correction would be sufficient to improve impingement free ROM? Methods: Ten patients were selected with symptomatic focal cam impingement lesions who underwent hip arthroscopy and had pre- and post-operative computed tomography (CT) scans. These patients were screened for normal acetabular morphology and demonstrated no radiographic signs of osteoarthritis. Pre- and post-operative 3D modeling of the involved hip was performed and subsequently dynamized with the femoral version set at (15, 5, -5 and -15 degrees) to define the impingement free ROM and location of impingement with maximum hip flexion and maximum hip internal rotation (IR) at 90 degrees of hip flexion. Results: Mean alpha angle pre and post cam resection were 66°±7.6 ° and 44°±4.9° respectively and were significantly different (p=0.003). Location of impingement shifted during hip flexion from the medial to anterior femoral neck with decreasing femoral version while the IR impingement location remained on the anterior femoral neck and was unaffected by femoral version. Kruskal-Wallis testing demonstrated decreasing femoral version significantly decreased hip flexion and IR ROM in both the pre and post cam resection groups (p&lt;0.0003). Impingement free ROM, as defined by hip flexion and IR greater than 90° and 10° respectively, was only identified in the 5 and 15 degree femoral anteversion models irrespective of whether cam femoroplasty had been performed. In the post cam resection group, hip IR ROM was significantly less with any level of decreasing femoral version (p&lt;0.002) while hip flexion ROM was significantly less with any level of decreased femoral version when compared to 15 degrees of anteversion (p&lt;0.04). When assessing the degree of change in ROM between the pre and post cam resection groups, femoral version had contrasting effects on hip ROM with decreasing femoral version showing less improvement with hip IR ROM while the femoral retroversion models had significantly greater improvements in hip flexion ROM when compared to the 15 degree anteversion model (p=0.02). Conclusions: Decreasing femoral version demonstrates significantly decreased hip flexion and IR both in the presence and absence of a CAM lesion. After cam femoroplasty, any level of decreased femoral version has a significant effect on hip ROM when compared to normal femoral anteversion. Femoral version seems to be the predominant factor in determining the amount of hip IR ROM in flexion and to a certain extent hip flexion ROM irrespective of the cam FAI. Impingement free ROM was only identified within the femoral anteversion models even after cam femoroplasty suggesting that recurrent mechanical collision and intra-articular damage seen with FAI may still be present with any level of true femoral retroversion. This study provides insight into the changes in hip flexion and IR that can be expected following both cam resection and simulated femoral osteotomy. [Table: see text]

Hip Range of Motion and Strength in Male Athletes with Stage 1 Osteitis Pubis: A Cross-Sectional and Correlational Study.

Background: The objectives of this study were: (1) to determine whether athletes with stage 1 osteitis pubis (OP) present differences in hip range of motion (ROM) and muscle strength, between both sides and compared with healthy athletes; (2) to investigate the relationship between the internal rotation (IR) ROM and pain intensity and physical function. Methods: a cross-sectional and correlational study was designed, in which 30 athletes (15 athletes with stage 1 OP and 15 healthy athletes) were included. Pain intensity, physical function, hip ROM and hip muscle strength were assessed. Results: The ROM assessment reported significant differences between both groups in the IR, external rotation (ER) and adduction (ADD) ROM of the painful side (PS) (p < 0.05). The OP group showed differences between both sides in IR ER and ADD ROM (p < 0.05). No statistically significant differences were found between or within groups in the maximum isometric strength of the hip (p > 0.05). A strong negative correlation between pain intensity and IR ROM (r = −0.640) and a strong positive correlation between physical function and IR ROM (r = 0.563) were found in the OP group. Conclusions: Male athletes with stage 1 OP present a hip IR, ER and ADD ROM limitation in the PS compared to non-PS and to healthy athletes. IR ROM is correlated to pain intensity and physical function in athletes with stage 1 OP.

Characteristics of Biomechanical and Physical Function According to Symptomatic and Asymptomatic Acetabular Impingement Syndrome in Young Adults.

Femoroacetabular impingement (FAI) is caused by hip joint anomalies. Although asymptomatic and symptomatic FAI have been reported in young adults, information on biomechanical and functional characteristics of FAI is rare. We compared the subjective hip score, range of motion (ROM), dynamic balance, and hip strength between symptomatic FAI (FAIsym) and asymptomatic FAI (FAIasym) groups and healthy controls. Participants (n = 307; men: 155, women: 152) were classified according to morphological abnormalities and hip joint symptoms, comprising symptomatic FAI, asymptomatic FAI, and healthy controls. The Copenhagen Hip and Groin Outcome Score (HAGOS), hip ROM, Y-balance test (YBT), and isokinetic hip strength were measured. The types of FAI were not significantly differenent in both men and women. FAIsym exhibited significantly reduced HAGOS, whereas FAIasym showed no significant difference compared to the healthy group (men: healthy 91.7 vs. FAIasym 87.2 vs. FAIsym 49.9, women: healthy 91.7 vs. FAIasym 86.2 vs. FAIsym 53.9). Hip flexion, adduction, and internal and external rotation ROMs were only significantly reduced in symptomatic FAI. Asymptomatic and symptomatic FAI groups displayed significantly lower YBT scores than healthy controls (men healthy: 84.9 vs. FAIasym: 69.0 vs. FAIsym 58.7, women healthy 79.2 vs. FAIasym 64.0 vs. FAIsym 55.5). Isokinetic hip flexion, adduction, and abduction strengths were significantly lower in FAIsym. In conclusion, FAIasym showed no decrease in muscle strength but displayed reduced dynamic balance. Subjective satisfaction, ROM, muscle strength, and dynamic balance were lower in FAIsym compared to FAIasym and healthy groups.

Fiabilidad intraexaminador e interexaminador de Clinometer para medir el rango de movimiento en pacientes con artrosis de cadera

ObjectiveTo evaluate the test–retest and inter-rater reliability of the application Clinometer for measuring the hip range of motion (ROM) in patients with hip osteoarthritis and its correlation with the universal goniometer. MethodsA blinded repeated measured was carried out with 35 patients with hip osteoarthritis. Hip internal rotation, external rotation, flexion and extension ROM were measured using Clinometer app by 2 independents raters. The intraclass correlation coefficient was used to calculate the test–retest reliability and inter-rater reliability. The standard error measurement and minimal detectable change were also calculated. The Pearson's correlation coefficient was used to correlate the app with the universal goniometer. ResultsClinometer application achieved excellent test–retest reliability (intraclass correlation coefficient: 0.82-0.96) and inter-rater reliability (intraclass correlation coefficient: 0.81-0.95) in all the ROMs assessed. The correlation analysis with the universal goniometer showed strong correlation values (r>0.70) in all the ROMs assessed. ConclusionClinometer application presented excellent test–retest reliability and inter-rater reliability for the measurement of hip ROM in patients with hip osteoarthritis. The smartphone application showed a strong correlation compared to universal goniometer.

Influence of lower limb torque, range of motion, and foot alignment in patellar rotation (Arno angle) in athletes

BackgroundAlterations of frontal plane patellar alignment could be related to lower limb disorders. Clinical assessment must be able to identify the influence of non-local factors in patellar alignment. ObjectiveTo identify the influence of lower limb torque, range of motion (ROM), and foot alignment on patellar rotation in healthy athletes. MethodsThis cross-sectional study was performed with 232 healthy basketball and volleyball elite athletes. Participants were assessed in preseason for: patellar medial and lateral rotation (Arno angle), passive hip internal rotation (IR) ROM, iliotibial band flexibility, hip abductors and external rotators (ER) torque, shank-forefoot alignment (SFA), and ankle dorsiflexion ROM. Hierarchical multiple linear regression was performed to identify if these variables and sex, age, and body mass could be associated with patellar rotation in a standing position. ResultsHip ER isometric torque explained a small part (10%) of the variance of the Arno angle in healthy athletes (R² change=0.10; unstandardized ß=11.74 (95% CI 6.82, 16.65); Standardized Coefficient Beta=0.32) and sex explained 2% of its variance (R² change=0.02; unstandardized ß= 2.42 (95% CI 0.32, 4.52); Standardized Coefficient Beta=0.15). After controlling for sex, hip ER torque explained 9% of Arno angle variance (R² change=0.09; unstandardized ß= 11.09 (95% CI 6.43, 15.76; Standardized Coefficient Beta=0.31). The other variables were not associated with patellar rotation. ConclusionsHip ER torque may influence patellar rotation in different directions (medial or lateral rotation). Possible mechanisms that explain the contribution of higher and lower hip ER torque in lateral and medial patellar rotation, respectively, are discussed.

Interaction of hip and foot factors associated with anterior knee pain in mountain bikers

ObjectiveTo investigate the association of interactions among trunk, hip, and foot/ankle musculoskeletal factors with the presence of anterior knee pain (AKP) in mountain bikers. DesignCross-sectional study. SettingPrivate clinical setting. ParticipantsFifty professional and amateur cyclists, with and without AKP, were included. Main outcome measuresBridge test with unilateral knee extension, hip stability isometric test (HipSIT), passive hip internal rotation (IR) range of motion (ROM), shank-forefoot alignment (SFA), and ankle dorsiflexion ROM were analyzed by classification and regression tree (CART) to identify interactions with AKP presence. A receiver-operating characteristic (ROC) curve verified accuracy of the model. To investigate strength of associations, prevalence ratios were calculated for each terminal node of the CART model. ResultsInteractions among passive hip IR ROM, HipSIT, ankle dorsiflexion ROM and SFA identified mountain bikers with and without AKP. The model achieved 76.9% sensitivity and 87.5% specificity. The area under the ROC curve was 0.86 (95% confidence interval: 0.75–0.97; standard error 0.05; p < 0.0001). ConclusionPresence of AKP in mountain bike cyclists was associated with interactions among passive hip IR ROM, HipSIT and ankle dorsiflexion ROM captured by CART, indicating that the contribution of one factor depends on the presence of other factors.

Validity and reliability of a smartphone goniometer application for measuring hip range of motions.

Mobile applications which are designed to assess the range of motion (ROM) are widely used. The aim of this cross-sectional observational study was to determine the inter-observer and intra-observer reliability of a smartphone application "PT Goniometer" (PTG) and determine the correlation between PTG and universal goniometer (UG) regarding active ROMs of the hip in healthy participants. Thirty-four healthy young participants were included in the study. Two physiotherapists performed active hip flexion, abduction, internal rotation and external rotation ROM measurements of dominant legs of the participants by using PTG and UG. Intraclass correlation coefficients (ICC) were calculated to determine the intra-observer and inter-observer reliability. Level of correlations between PTG and UG were used to establish concurrent validity of PTG. The PTG demonstrated excellent inter-observer and intra-observer reliability (ICC > 0.90) for all measured hip movements. The minimum detectable change (MDC95) was ranged from 3.29° to 5.1° for the intra-observer reliability, and from 2.55° to 3.21° for the inter-observer reliability. Additionally, the concurrent validity was found excellent (r = 0.91-0.93). The results of the present study suggest that PTG is a valid and reliable mobile technology for measuring hip ROMs.

Squatting Throwing Is Not Associated With Increased Medial Elbow Torque in Youth Baseball Catchers

To compare medial elbow stress during squatting throwing, standing throwing, and maximum effort throwing and to analyze its relationships with throwing variables and the hip joint internal rotation (IR) range of motion (ROM) in youth baseball catchers. Forty-five youth baseball catchers were recruited. Exclusion criteria included pain during throwing, history of surgery, or upper-extremity injuries within 12 months. Catchers performed 5 throws for each of the following throwing conditions: squatting throwing, standing throwing, and maximum effort throwing. Catchers were outfitted with a wearable sensor sleeve that recorded the medial elbow torque, arm speed, and shoulder rotation. Ball velocity was measured using a radar gun. Final analysis included 42 catchers (mean age, 11.5 ± 1.2 years; mean catcher experience, 16.7 ± 10.3 months). The medial elbow torque was significantly greater during maximum effort throwing (19.0 ± 5.2 Nm) than during squatting throwing (14.3 ± 5.4 Nm) and standing throwing (15.7 ± 4.7 Nm) (both P < .001); there was no significant difference between squatting throwing and standing throwing. Multiple linear regression analysis showed that the ball velocity was significantly positively associated with the medial elbow torque during squatting throwing and standing throwing (P= .023 and P= .029, respectively). During squatting throwing, the hip IR ROM on the throwing side was significantly negatively associated with the medial elbow torque (P= .011). The medial elbow torque during squatting throwing was equivalent to that during standing throwing. Increased medial elbow torque was associated with greater ball velocity during squatting throwing and standing throwing and with decreasing hip joint IR ROM on the throwing side during squatting throwing. Evaluation and stretching of the hip joint IR ROM on the throwing side may be important to decrease elbow stress during squatting throwing in youth baseball catchers. Level II, prospective comparative observational trial.

Gender Differences in Kinematic Analysis of the Lower Limbs during the Chasse Step in Table Tennis Athletes.

The chasse step is one of the most important footwork maneuvers used in table tennis. The purpose of this study was to investigate the lower limb kinematic differences of table tennis athletes of different genders when using the chasse step. The 3D VICON motion analysis system was used to capture related kinematics data. The main finding of this study was that the step times for male athletes (MA) were shorter in the backward phase (BP) and significantly longer in the forward phase (FP) than for female athletes (FA) during the chasse step. Compared with FA, knee external rotation for MA was larger during the BP. MA showed a smaller knee flexion range of motion (ROM) in the BP and larger knee extension ROM in the FP. Moreover, hip flexion and adduction for MA were significantly greater than for FA. In the FP, the internal rotational velocity of the hip joint was significantly greater. MA showed larger hip internal rotation ROM in the FP but smaller hip external rotation ROM in the BP. The differences between genders can help coaches personalize their training programs and improve the performance of both male and female table tennis athletes.

The Effect of Hip Joint Mobilizations Using a Mobilization Belt on Hip Range of Motion and Functional Outcomes.

Joint mobilizations have been studied extensively in the literature for the glenohumeral joint and talocrural joint (ankle). Consequently, joint mobilizations have been established as an effective means of improving range of motion (ROM) within these joints. However, there is a lack of extant research to suggest these effects may apply within another critical joint in the body, the hip. To examine the immediate effects of hip joint mobilizations on hip ROM and functional outcomes. Secondarily, this study sought to examine the efficacy of a novel hip mobilization protocol. A prospective exploratory study. Two research labs. The study included 19 active male (n = 8) and female (n = 11) college students (20.56 [1.5]y, 171.70 [8.6]cm, 72.23 [12.9]kg). Bilateral hip mobilizations were administered with the use of a mobilization belt. Each participant received hip joint mobilization treatments once during 3 weekly sessions followed immediately by preintervention and postintervention testing/measurements. Testing for each participant occurred once per week, at the same time of day, for 3 consecutive weeks. Hip ROM was the first week, followed by modified Star Excursion Balance Test the second week and agility T test during the third week. Pretest and posttest measurements included hip ROM for hip flexion, extension, abduction, adduction, internal and external rotation, as well as scores on the modified Star Excursion Balance Test (anterior, posterolateral, and posteromedial directions) and agility T test. A significant effect for time was found for hip adduction, internal and external rotation ROM, as well as the posterolateral and posteromedial directions of the modified Star Excursion Balance Test. A separate main effect for both limbs was found for adduction and internal rotation ROM. Isolated immediate changes in ROM and functional outcomes were evident. Further evaluation is needed.