Hip Internal Rotation Research Articles

Lumbopelvic-Hip Rhythm in People with Lumbar Flexion-with-Rotation Syndrome during Hip Internal Rotation.

According to previous research, hip internal rotation (HIR) aggravates low back pain (LBP) symptoms, especially in patients with lumbar flexion with rotation (F + R) syndrome. Therefore, the present study aimed to examine the lumbopelvic-hip rhythm during the HIR test in patients with this syndrome. In this cross-sectional study, 20 men without LBP and 20 matched men with LBP, subcategorized in the F+R subgroup, participated. The participants performed the HIR test. Kinematics data were recorded using a motion analysis system. After processing the kinematics, a comparison was made in the hip and pelvic kinematics between the groups. A statistical analysis based on an independent t test revealed a significant increased (P < 0.05) pelvic rotation during the tests with the dominant ( P = 0.007) and nondominant limbs (P = 0.025) in those with LBP. The analysis also showed that during the test with the dominant lower limb, the pelvis and hip moved with a more synchronized pattern in patients with LBP (P = 0.001). In the patients with lumbar F + R syndrome, there was a tendency for early pelvic rotation during the dominant HIR test. Moreover, LBP people also exhibited a greater pelvic rotation range of motion in the first half and whole pathways of the test. These impairments could be a risk factor for the development of LBP symptoms in these patients.

Predictive simulation of single-leg landing scenarios for ACL injury risk factors evaluation.

The Anterior Cruciate Ligament (ACL) rupture is a very common knee injury during sport activities. Landing after jump is one of the most prominent human body movements that can lead to such an injury. The landing-related ACL injury risk factors have been in the spotlight of research interest. Over the years, researchers and clinicians acquire knowledge about human movement during daily-life activities by organizing complex in vivo studies that feature high complexity, costs and technical and most importantly physical challenges. In an attempt to overcome these limitations, this paper introduces a computational modeling and simulation pipeline that aims to predict and identify key parameters of interest that are related to ACL injury during single-leg landings. We examined the following conditions: a) landing height, b) hip internal and external rotation, c) lumbar forward and backward leaning, d) lumbar medial and lateral bending, e) muscle forces permutations and f) effort goal weight. Identified on related research studies, we evaluated the following risk factors: vertical Ground Reaction Force (vGRF), knee joint Anterior force (AF), Medial force (MF), Compressive force (CF), Abduction moment (AbdM), Internal rotation moment (IRM), quadricep and hamstring muscle forces and Quadriceps/Hamstrings force ratio (Q/H force ratio). Our study clearly demonstrated that ACL injury is a rather complicated mechanism with many associated risk factors which are evidently correlated. Nevertheless, the results were mostly in agreement with other research studies regarding the ACL risk factors. The presented pipeline showcased promising potential of predictive simulations to evaluate different aspects of complicated phenomena, such as the ACL injury.

The Association of Trunk and Hip Kinematic With Knee Abduction Angle During Single-Leg Landing

Objectives: Children aged 10 to 12 years often show dangerous maneuvers during landing, which include increased knee valgus, placing them at higher risk of anterior cruciate ligament (ACL) injuries. The study aimed to investigate the relation of the trunk and hip kinematics with the peak knee abduction angle during single-leg landing among preadolescent female soccer players. Methods: Thirty-six preadolescent female soccer players aged 10 to 12 years attended the study. Participants did a static trial and after that performed landing trials. A single-leg landing was applied to assess the landing kinematics. A three-dimensional motion capture system was applied to analyze trunk, hip, and knee kinematics. Results: Pearson correlation coefficient demonstrated a significantly positive relationship between peak hip internal rotation angle (r=0.361) (P=0.03) and peak knee abduction angle. Furthermore, no significant relationship was identified between peak hip adduction (r=-0.102) (P=0.55), peak trunk rotation (r=0.239) (P=0.16), peak trunk lateral flexion (r=0.052) (P=0.76), and peak valgus knee. Discussion: Peak hip rotation angle was correlated with the valgus knee with a weak correlation value among preadolescent female soccer players. Future studies should consider kinematic risk factors related to ACL injuries in combination with neuromuscular control trunk and hip during more demanding tasks.

Diagnostics Using the Change-of-Direction and Acceleration Test (CODAT) of the Biomechanical Patterns Associated with Knee Injury in Female Futsal Players: A Cross-Sectional Analytical Study

The primary aim of this study was to identify kinematic differences at initial contact between female futsal players with and without previous knee injury, using a functional motor pattern test. The secondary aim was to determine kinematic differences between the dominant and non-dominant limb in the whole group, using the same test. A cross-sectional study was performed in 16 female futsal players allocated into two groups: eight females with a previous knee injury, i.e., affected by the valgus collapse mechanism without surgical intervention, and eight with no previous injury. The evaluation protocol included the change-of-direction and acceleration test (CODAT). One registration was made for each lower limb, i.e., the dominant (the preferred kicking limb) and non-dominant limb. A 3D motion capture system (Qualisys AB, Göteborg, Sweden) was used to analyze the kinematics. The Cohen's d effect sizes between the groups demonstrated a strong effect size towards more physiological positions in the non-injured group in the following kinematics in the dominant limb: hip adduction (Cohen's d = 0.82), hip internal rotation (Cohen's d = 0.88), and ipsilateral pelvis rotation (Cohen's d = 1.06). The t-test for the dominant and non-dominant limb in the whole group showed the following differences in knee valgus: dominant limb (9.02 ± 7.31 degrees) and non-dominant limb (1.27 ± 9.05 degrees) (p = 0.049). Conclusions: The players with no previous history of knee injury had a more physiological position for avoiding the valgus collapse mechanism in the hip adduction and internal rotation, and in the pelvis rotation in the dominant limb. All the players showed more knee valgus in the dominant limb, which is the limb at greater risk of injury.

The effect of patient positioning on measurements of bone mineral density of the proximal femur: a simulation study using computed tomographic images.

Several studies have analyzed the effect of hip rotation on the measurement of bone mineral density (BMD) of the proximal femur by dual-energy x-ray absorptiometry (DXA). However, as the effects of hip flexion and abduction on BMD measurements remain uncertain, a computational simulation study using CT images was performed in this study. Hip CT images of 120 patients (33 men and 87 women; mean age, 82.1 ± 9.4 years) were used for analysis. Digitally reconstructed radiographs of the proximal femur region were generated from CT images to calculate the BMD of the proximal femur region. BMD at the neutral position was quantified, and the percent changes in BMD when hip internal rotation was altered from -30° to 15°, when hip flexion was altered from 0° to 30°, and when hip abduction was altered from -15° to 30° were quantified. Analyses were automatically performed with a 1° increment in each direction using computer programming. The alteration of hip angles in each direction affected BMD measurements, with the largest changes found for hip flexion (maximum change of 17.7% at 30° flexion) and the smallest changes found for hip rotation (maximum change of 2.2% at 15° internal rotation). The BMD measurements increased by 0.34% for each 1° of hip abduction, and the maximum change was 12.3% at 30° abduction. This simulation study quantified the amount of BMD change induced by altering the hip position. Based on these results, we recommend that patients be positioned carefully when acquiring DXA images.

The Variable Influence of Orthotic Management on Hip and Pelvic Rotation in Children with Unilateral Neurogenic Equinus Deformity.

Equinus deformity with or without concomitant drop foot is a common finding in children with unilateral spastic cerebral palsy and spastic hemiplegia of other causes. Hypothetically, these deformities may lead to pelvic retraction and hip internal rotation during gait. Orthoses are used to reduce pes equinus during gait and to restore hindfoot first contact. We aimed to investigate whether the use of orthotic equinus correction reduces rotational hip and pelvic asymmetries. In a retrospective study, 34 children with unilateral spastic cerebral palsy or spastic hemiplegia of other causes underwent standardized instrumented 3D gait analysis with and without orthotic equinus management. We analyzed the differences in the torsional profile during barefoot walking and while wearing orthoses, as well as investigated the influence of ankle dorsiflexion and femoral anteversion on pelvic and hip kinematics and hip kinetics. Wearing orthoses corrected pes equinus and pelvic internal rotation at the end of the stance phase and in the swing phase compared to barefoot walking. Hip rotation and the rotational moment did not significantly change with orthoses. Orthotic management or femoral anteversion did not correlate to pelvic and hip asymmetry. The findings indicate that the correction of the equinus by using orthoses had a variable effect on the asymmetry of the hip and pelvis and internal rotation; both appear to have a multifactorial cause that is not primarily driven by the equinus component.

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.

Association of Proximal and Distal Factors With Lower Limb Kinematics During a Classical Ballet Jump

Excessive dynamic lower limb misalignment may predispose ballet dancers to jump-related injuries. However, it is unknown whether proximal and distal factors influence this movement pattern. The aim of this study was to investigate whether hip abduction strength, foot alignment, and ankle dorsiflexion range of motion (ROM) are associated with peak angles of hip adduction and internal rotation and knee abduction during the preparation and landing phases of a classical ballet jump. Cross-sectional study. Forty-one healthy amateur ballet dancers were included. Hip abduction strength was evaluated isometrically using a handheld dynamometer, foot alignment was determined by the shank-forefoot alignment, and weight-bearing ankle dorsiflexion ROM was measured by performing the lunge test. Peak hip and knee angles were analyzed 3-dimensionally during the preparation and landing phases of a single-leg jump. A Pearson correlation matrix was used to investigate the association of hip abduction strength, shank-forefoot alignment, and ankle dorsiflexion ROM with peak angles of hip adduction and internal rotation and knee abduction during the preparation and landing phases of the jump. Greater hip abduction strength was associated with greater peak hip internal rotation angle (r = .43, P < .05), but not with peak hip adduction and knee abduction angles during the preparation phase of the jump. There were no associations of shank-forefoot alignment and ankle dorsiflexion ROM with peak hip and knee angles during the preparation (r = -.23 to .36, P > .05) and landing (r = -.20 to .24, P > .05) phases of the jump. There was no association of hip abduction strength with peak hip and knee angles during the landing phase of the jump (r = -.28 to .16, P > .05). Hip abductors strengthening, correction of foot misalignments, and increasing ankle dorsiflexion ROM may not prevent excessive hip and knee movements during a classical ballet single-leg jump in amateur dancers.

Hip Abduction Can Be Considered the Sole Posterior Precaution Strategy to Lower the Rate of Impingement After Posterior Approach Total Hip Arthroplasty With Large Femoral Head: A Computer Simulation Study

BackgroundStudies suggest that posterior hip precautions are unnecessary after total hip arthroplasty; however, many surgeons and patients choose to follow these precautions to some extent. In this study, we hypothesized that 20° of hip abduction would be sufficient to prevent impingement and dislocation in motions requiring hip flexion when using larger prosthetic heads (≥36 mm) when the acetabular implant is placed within a reasonable orientation (anteversion:15-25° and inclination: 40-60°). MethodsUsing a robotic hip platform, we investigated the effect of hip abduction on prosthetic and bony impingement in 43 patients. For the flexed seated position, anterior pelvic tilt angles of 10 and 20° were chosen, while anterior pelvic tilt angles of 70 and 90° were chosen for the bending forward position. An additional 10° of hip external rotation and 10 or 20° of hip internal rotation were also added to the simulation. One hip received a 32-mm head; otherwise, 36-, 40-mm, or dual-mobility heads were used. The study power was 0.99, and the effect size was 0.644. ResultsIn 65% of the cases, bone-bone impingement between the calcar and anterior-inferior iliac spine was the main type of impingement. The absolute risk of impingement decreased between 0 and 16.3% in both tested positions with the addition of 20° hip abduction. ConclusionWith modern primary total hip arthroplasty stems (low neck diameter) and an overall acceptable cup anteversion angle, small degrees of hip abduction may be the only posterior hip precaution strategy required to lower the risk of dislocation among patients. Future studies can potentially investigate the concept of personalized hip precautions based on preoperative computer simulations, utilized implants, hip-spine relations, and final implant orientation.

Predicting injury risk using machine learning in male youth soccer players

The aim of this study was twofold: a) to build models using machine learning techniques on data from an extensive screening battery to prospectively predict lower extremity soft tissue (LE-ST) injuries in non-elite male youth soccer players, and b) to compare models' performance scores (i.e., predictive accuracy) to select the best fit. A sample of 260 male youth soccer players from the academies of five different Spanish non-professional clubs completed the follow-up. Players were engaged in a pre-season assessment that covered several personal characteristics (e.g., anthropometric measures), psychological constructs (e.g., trait-anxiety), and physical fitness and neuromuscular measures (e.g., range of motion [ROM], landing kinematics). Afterwards, all LE-ST injuries were monitored over one competitive season. The predictive ability (i.e., area under the receiver operating characteristic curve [AUC] and F-score) of several screening models was analysed and compared to select the one with the highest scores. A total of 45 LE-ST injuries were recorded over the season. The best fit screening model developed (AUC = 0.700, F-score = 0.380) allowed to successfully identify one in two (True Positive rate = 53.7 %) and three in four (True Negative rate = 73.9 %) players at high or low risk of suffering a LE-ST injury throughout the in-season phase, respectively, using a subset of six field-based measures (knee medial displacement in the drop jump, asymmetry in the peak vertical ground reaction force during landing, body mass index, asymmetry in the frontal plane projection angle assessed through the tuck jump, asymmetry in the passive hip internal rotation ROM, and ankle dorsiflexion with the knee extended ROM). Given that these measures require little equipment to be recorded and can be employed quickly (approximately 5–10 min) and easily by trained staff in a single player, the model developed might be included in the injury management strategy for youth soccer.

The reliability of lower limb 3D gait analysis variables during a change of direction to 90- and 135-degree manoeuvres in recreational soccer players.

Several biomechanical outcomes are being used to monitor the risk of injuries; therefore, their reliability and measurement errors need to be known. To measure the reliability and measurement error in lower limb 3D gait analysis outcomes during a 90∘ and 135∘ change of direction (COD) manoeuvre. A test re-test reliability study for ten healthy recreational players was conducted at seven-day intervals. Kinematics (Hip flexion, adduction, internal rotation angles and knee flexion abduction angles) and kinetics (Knee abduction moment and vertical ground reaction force) data during cutting 90∘ and 135∘ were collected using 3D gait analysis and force platform. Five trials for each task and leg were collected. Standard error of measurement (SEM) and the intraclass correlation coefficient (ICC) were calculated from the randomised leg. The ICC values of the kinematics, kinetics, and vertical ground reaction force (VGRF) outcomes (90∘ and 135∘) ranged from 0.85 to 0.95, showing good to excellent reliability. The SEM for joint angles was less than 1.69∘. The VGRV showed a higher ICC value than the other outcomes. The current study results support the use of kinematics, kinetics, and VGRF outcomes for the assessment of knee ACL risk in clinic or research. However, the hip internal rotation angle should be treated with caution since the standard measurement error exceeded 10% compared to the mean value. The measurement errors provided in the current study are valuable for future studies.

Isolated Adductor Magnus Injuries in Athletes: A Case Series.

Little is known about injuries to the adductor magnus (AM) muscle and how to manage them. To describe the injury mechanisms of the AM and its histoarchitecture, clinical characteristics, and imaging features in elite athletes. Case series; Level of evidence, 4. A total of 11 competitive athletes with an AM injury were included in the study. Each case was clinically assessed, and the diagnosis and classification were made by magnetic resonance imaging (MRI) according to the British Athletics Muscle Injury Classification (BAMIC) and mechanism, location, grade, and reinjury (MLG-R) classification. A 1-year follow-up was performed, and return-to-play (RTP) time was recorded. Different mechanisms of injury were found; most of the athletes (10/11) had flexion and internal rotation of the hip with extension or slight flexion of the knee. Symptoms consisted of pain in the posteromedial (7/11) or medial (4/11) thigh during adduction and flexion of the knee. Clinically, there was a suspicion of an injury to the AM in only 3 athletes. According to MRI, 5 lesions were located in the ischiocondylar portion (3 in the proximal and 2 in the distal myoconnective junction) and 6 in the pubofemoral portion (4 in the distal and 2 in the proximal myoconnective junction). Most of the ischiocondylar lesions were myotendinous (3/5), and most of the pubofemoral lesions were myofascial (5/6). The BAMIC and MLG-R classification coincided in distinguishing injuries of moderate and mild severity. The management was nonoperative in all cases. The mean RTP time was 14 days (range, 0-35 days) and was longer in the ischiocondylar cases than in the pubofemoral cases (21 vs 8 days, respectively). Only 1 recurrence, at <10 months, was recorded. Posteromedial thigh pain after an eccentric contraction during forced adduction of the thigh from hip internal rotation should raise a suspicion of AM lesions. The identification of the affected portion was possible on MRI. An injury in the ischiocondylar portion entailed a longer RTP time than an injury in the pubofemoral portion.

Variables Associated With Knee Valgus in Male Professional Soccer Players During a Single-Leg Vertical Landing Task.

Prior studies have explored the relationship between knee valgus and musculoskeletal variables to formulate injury prevention programs, primarily for females. Nonetheless, there is insufficient evidence pertaining to professional male soccer players. Here, the aim was to test the correlation of lateral trunk inclination, hip adduction, hip internal rotation, ankle dorsiflexion range of motion, and hip isometric strength with knee valgus during the single-leg vertical jump test. Twenty-four professional male soccer players performed a single-leg vertical hop test, hip strength assessments, and an ankle dorsiflexion range of motion test. A motion analysis system was employed for kinematic analysis. Maximal isometric hip strength and ankle dorsiflexion range of motion were tested using a handheld dynamometer and a digital inclinometer, respectively. The correlation of peak knee valgus with peak lateral trunk inclination was .43 during the landing phase (P = .04) and with peak hip internal rotation was -.68 (P < .001). For knee valgus angular displacement, only peak lateral trunk inclination presented a moderate positive correlation (r = .40, P = .05). This study showed that trunk and hip kinematics are associated with knee valgus, which could consequently lead to increased knee overload in male professional soccer players following a unilateral vertical landing test.

Effects of Core Stability Training on Kinematic and Kinetic Variables in Patients With Chronic Low Back Pain

Purpose: This study aims to assess the effects of an 8-week core stability training on the kinematics and kinetics of trunk flexion and extension motions in patients with chronic non-specific low back pain (CNSLBP). Methods: A total of 30 CNSLBP patients with the age range of 25 to 45 years were randomly divided into 2 equally sized groups. The subjects were identified through clinical examination. Before and after the training, tests were applied to assess peak 3-dimensional hip joint moments, peak negative and positive hip joint powers, and lumbopelvic coupling angles during trunk flexion and extension motions. The first group underwent an 8-week core stability training program, including the specific exercise of the deep muscles of abdominal along with the lumbar multifidus co-activation. After the 8-week program, the post-test stage was performed similarly to the pre-test. Results: The main effects of “time” (P=0.029, f=0.84) and “time-by-group” interactions (P=0.03, f=0.16) for hip abductor moments and internal rotator moment (P=0.03, f=0.87) were significant. A trend toward the statistically significant main effect of “time” was found for the coupling angle during the flexion phase (P&lt;0.05, f=1.88), extension phase (P=0.02, f=0.93), and “time×group” interaction during the flexion (P&lt;0.05, f=1.96), extension (P=0.01, f=0.96) phases. Conclusion: Core stability training has the potential to improve kinematics and kinetics during trunk flexion and extension motions in patients with CNSLBP.

The effects of the Posterior X Taping versus augmented feedback on lower-extremity kinematic and muscle activity pattern during unilateral weight-bearing activities in men with tibiofemoral varus malalignment

PurposeTibiofemoral Varus Malalignment (TFRV) contributes to overuse injuries by altering lower limb biomechanics. Both Posterior X Taping (PXT) and Real Time Feedback (RTF), have each been recommended for subjects with TFRV as they are thought to enhance control of excessive tibiofemoral rotations. This paper evaluates this claim.MethodsA total of recreational male 24 athletes with TFRV participated in the current study. Kinematic and electromyography variables of lower extremity were synchronously ​recorded on five consecutive repetitions of the single-legged-squat (SLS) and forward-step-down) FSD) tasks before and after applications of PXT and RTF.ResultsThe subjects at post-intervention in RTF group exhibited decreased hip adduction during FSD, and decreased hip adduction and internal rotation during eccentric and concentric phases of the SLS; Additionally, we observed increased gluteus medius activity during eccentric phase of the SLS and FSD tasks. In contrast, subjects at the post-intervention in PXT group exhibited decreased tibiofemoral external rotation and increased ankle external rotation during all the phases of both SLS and FSD tasks.ConclusionThese results suggest that the PXT and RTF interventions are recommended to immediately improve the functional defects of the subjects with TFRV during SLS and FSD tasks.

The functional role of hip muscles during gait in patients with increased femoral anteversion

BackgroundFemoral anteversion affects the lever arm and moment-generating capacity of the hip abductors, while an increased hip internal rotation during walking was proposed to be a compensatory mechanism to restore the abductive lever arm. Children with isolated increased femoral anteversion, however, do not always present a deficit in the net hip abduction moment during gait, suggesting that a more comprehensive understanding of the effect of morphology and motion on muscle forces and moments is needed to aid clinical decision making. Research questionAre muscle contributions to hip joint moments and muscle forces altered in patients with increased femoral anteversion and internally rotated gait pattern compared to a control group of typically developing children? And how would the functional role of the muscle be altered if the patients walked straight? MethodsThis follow-up study compared patients with increased femoral anteversion (n = 42, 12.8 ± 1.9 years, femoral anteversion: 39.6 ± 6.9°) to controls (n = 9, 12.0 ± 3.0 years, femoral anteversion: 18.7 ± 4.1°). Muscle forces and moment contributions were calculated using personalized musculoskeletal models. Additionally, a hypothetical scenario, in which the gait of the controls was modelled with an anteverted femoral morphology, was used to understand what would happen if the patients walked straight. ResultsGluteus medius abductive contribution was lower in patients compared to controls, despite a comparable net abduction moment around the hip. Patients presented lower muscle forces. However, if modelled to walk straight, they would require higher forces as well as a larger co-contraction of both hip internal and external rotators in the transversal plane. SignificanceThis study suggests that patients with increased femoral anteversion walking with an internally rotated gait pattern present lower muscle forces, but when modelled to walk straight muscle forces increase. The current results provide important information to better understand this condition and improve treatment recommendations in these patients.

Do exist differences in kinematics and EMG of the hip and knee between male runners with and without patellofemoral pain in different running speeds?

ObjectivePatellofemoral pain (PFP) presents a higher prevalence in female runners, while PFP in male is somehow neglected. Moreover, the effects of progressive greater running speed have not been reported. This study investigates the influence of progressive greater running speed on lower limb tridimensional kinematics and muscle activation (EMG) in male runners with PFP while compared with controls. DesignCross-Sectional Design. MethodsThirteen runners with PFP and 18 controls ran in a treadmill under three different speeds: 9, 11, and 13 km/h. Principal component scores from kinematic data and EMG onset and amplitude were used to compare groups through the Mann-Whitney test at each running speed. ResultsMale PFP subjects presented increased hip internal rotation at 11 km/h and increased hip and knee internal at 13 km/h, as well as reduced knee adduction at all speeds. PFP subjects also ran with delayed and shorter vastus medialis oblique pre-activation compared with normal subjects. ConclusionsThis study demonstrated that PFP increased knee and hip internal rotation at higher demand running, therefore, it is important to evaluate the transverse plane of the hip and knee biomechanics in male runners with PFP to optimize the rehabilitation and reconditioning method of these subjects.

Between-day reliability and minimum detectable change of the Conventional Gait Model 2 and Plug-in Gait Model during running

BackgroundThe Plug-in Gait model (PiG) is commonly used in 3D motion analysis but has limited reliability. Although an improved version of PiG has been developed, called the Conventional Gait Model 2 (CGM2), there is limited evidence on its between-day reliability for running. Research questionWhat is the between-day intraclass correlation coefficient (ICC3,k) and minimum detectable change (MDC) of lower limb kinematics and kinetics for CGM2 during running and does reliability differ between CGM2 and PiG. MethodsTwenty-three healthy participants performed running at a comfortable speed in two identical test sessions at least 5 days apart. Lower limb kinematic and kinetic data in the three planes of motion were calculated using CGM2 and PiG. The ICC and MDC were calculated for the kinematic and kinetic parameters at initial contact and peak during the stance phase of running. ResultsCGM2 kinematics showed good-to-excellent reliability (ICC: 0.75–0.93), except for hip extension and ankle internal rotation, and less than 5° MDC (1.8°−4.9°) of the coronal and sagittal planes, except for hip extension. PiG showed poor-to-moderate reliability (ICC: −0.15 to 0.72) in the coronal and transverse planes and greater than 5° MDC (5.0°−21.8°), except for knee extension, adduction, and ankle dorsiflexion. CGM2 showed good-to-excellent reliability for peak kinetics (ICC: 0.75–0.97), except for hip internal rotation and knee extension. The ICC and MDC were higher for CGM2 than PiG, with significant differences in the coronal plane of the hip and knee joints and transverse plane of the hip joint in kinematics and in the sagittal and coronal plane of the hip and knee joints in kinetics. SignificanceThe between-day reliability of CGM2 was mostly good to excellent for lower limb kinematics and kinetics during running. We believe that CGM2 can more accurately assess kinematic differences between the coronal and transverse planes than the PiG.

Effect of Flat Running Shoes on Hip Kinematics in Male Recreational Runners.

Patellofemoral joint pain and iliotibial band syndrome are very common running-related injuries. Excessive contralateral pelvic drop, hip adduction, and hip internal rotation have been suggested to be associated with the two injuries. The purpose of this repeated measures and the cross-sectional study was to investigate the effect of flat running shoes on these kinematic variables compared with that of conventional running shoes with a 10 mm drop. Eighteen male recreational runners were recruited to run in flat shoes and conventional shoes with a 10 mm drop, in random order. Impact force data and lower extremity kinematics were synchronously obtained using two Kistler force plates and eight motion infrared cameras, whereas differences in the impact force and hip kinematics were compared using statistical parametric mapping. Regarding hip kinematics, the hip flexion (p = 0.004) and adduction angles (p = 0.004) decreased significantly at 30-70% and 62-85% of the stance phase, respectively, while wearing flat running shoes; the contralateral pelvic drop angle (p = 0.001) decreased significantly at 31-75% of the stance phase while wearing flat running shoes. The knee internal rotation angle (p = 0.035) decreased significantly at 8-17% of the stance phase while wearing flat running shoes compared with conventional running shoes. Given that these kinematic variables are associated with patellofemoral joint pain and iliotibial band syndrome, flat running shoes may have potential benefits for the prevention or treatment of knee injuries.

The association between hip strength, physical function and dynamic balance in people with unilateral knee osteoarthritis: A cross-sectional study

BackgroundIn people with knee osteoarthritis, the association between multidirectional hip strength and physical function or balance is unknown. ObjectiveTo determine the relationship between hip flexion, extension, abduction, adduction, external and internal rotation strength and (1) physical function and (2) dynamic balance. DesignCross-sectional. MethodsForty-seven participants (20 men and 27 women, age 66.2 ± 8.2 years) with unilateral knee osteoarthritis were included. Hip strength was assessed with hand-held dynamometry; physical function was assessed with the 40m fast-paced walk test (40mFPWT), 30-s chair-stand test (30sCST), and stair-climb test (SCT); and dynamic balance was assessed in 3 directions using the Star Excursion Balance Test. Multivariable linear regression analysis was used to determine the strength of relationships between measures. ResultsHip strength, in all directions except for internal rotation, was positively associated with better physical function (40mFPWT: R2 = 0.48 to 0.65; SCT: R2 = 0.5 to 0.54; 30sCST: R2 = 0.39 to 0.42), and dynamic balance (anterior: R2 = 0.33 to 0.45; posteromedial: R2 = 0.32 to 0.45; posterolateral: R2 = 0.27 to 0.35). Hip strength, after adjusting for knee extension strength, explained an additional 8%–12% (p < 0.05) and 5%–12% (p < 0.05) reach in the anterior and posteromedial directions of the Star Excursion Balance Test, respectively. ConclusionsHip strength in multiple directions is associated with measures of physical function and dynamic balance in people with unilateral knee osteoarthritis. Clinicians are encouraged to consider hip strength in multiple directions in the context of the patients’ functional and/or balance goals when developing exercise programs for people with knee osteoarthritis.