Hip External Rotation Moments Research Articles

Gait analysis and clinical outcomes of anterior and lateral approach total hip arthroplasty: A prospective randomized study

Objectives: This study compared the lateral and direct anterior approaches (DAAs) for total hip arthroplasty (THA) regarding gait analysis and post-operative outcomes. Methods: Patients undergoing THA for osteonecrosis or primary osteoarthritis were randomized to either the lateral or DAA. Standardized surgical procedures and implants were used. Gait analysis, including temporal distance parameters, kinetics, and kinematics, was conducted at 6 weeks, 3 months, and 18 months. Results: Thirty-four patients (16 lateral, 18 anterior) participated, with comparable demographics. At 6 weeks, the anterior approach group had significantly higher Harris hip scores, improved gait speed, greater hip extension and external rotation moments, higher peak hip abduction angle, and reduced peak hip extension angle. The lateral approach (LA) group showed decreased hip abduction and internal rotation moments. By 3 and 18 months, outcomes were similar between groups. Conclusion: The anterior approach facilitates faster rehabilitation at 6 weeks, but outcomes converge with the LA by 3 and 18 months postoperatively.

Postural Control During Single-Leg Landing in Female Athletes After Anterior Cruciate Ligament Reconstruction.

Secondary anterior cruciate ligament (ACL) injury is a complication of ACL reconstruction (ACLR), which may result from altered neuromuscular control affecting anticipatory postural adjustments (APAs) and compensatory postural adjustments (CPAs) required for maintaining balance during movement. However, it remains unclear how APAs and CPAs differ in single-leg landings post-ACLR compared to healthy subjects. The purpose of this study was to clarify the differences in muscle activities of APAs and CPAs, lower limb kinematics, and kinetics between athletes with a history of ACLR and healthy athletes during single-leg landing. Cross-sectional study. Eighteen female athletes were recruited and divided into ACLR (n = 9) and control groups (n = 9). The experimental task involved a single-leg landing from a 30 cm box. Joint angles and moments were determined using a 3-dimensional motion analysis system, while muscle activity was assessed using surface electromyography. Analysis intervals were divided into two phases: the APA phase (-150 ms to 50 ms) and the CPA phase (50 ms to 250 ms), with initial contact (0 ms) as the reference point. Muscle activity onset time was defined as the time when the baseline exceeded by the sum of mean values and 2 standard deviations. No significant differences were observed in muscle activity or onset time between the ACLR and control groups. However, an increased hip external rotation moment was observed during the CPA phase in the ACLR group. These findings suggest that APAs and CPAs of athletes who returned to sports more than 1 year post-ACLR may be similar. The increased hip external rotation moment in the ACLR group during the CPA phase could represent a specific compensatory strategy to decrease the hip internal rotation angle post-ACLR. III.

Are hip biomechanics during running associated with symptom severity or cam morphology size in male football players with FAI syndrome?

BackgroundFemoroacetabular impingement (FAI) syndrome is considered a motion-related condition. Little is known about the influence of symptom severity and cam morphology on hip biomechanics for individuals with FAI syndrome. Research questionAre hip biomechanics during running associated with symptom severity or cam morphology size in male football players with FAI syndrome? MethodsForty-nine male, sub-elite football (soccer or Australian football) players (mean age= 26 years) with FAI syndrome completed the International Hip Outcome Tool-33 (iHOT-33) and Copenhagen Hip and Groin Outcome Score (HAGOS) and underwent radiographic evaluation. Biomechanical data were collected during overground running (3–3.5 m∙s−1) using three-dimensional motion capture technology and an embedded force plate. Various discrete hip angles and impulses of joint moments were analysed during the stance phase. Linear regression models investigated associations between running biomechanics data (dependent variables) and iHOT-33 and HAGOS scores and cam morphology size (independent variables). ResultsHip joint angles during running were not associated with symptom severity in football players with FAI syndrome. A positive association was found between the impulse of the hip external rotation moment and HAGOS-Sport scores, such that a smaller impulse magnitude occurred with a lower HAGOS-Sport score (0.026 *10−2 [95%CI <0.001 *10−2 to 0.051 *10−2], P = 0.048). Larger cam morphology was associated with a greater peak hip adduction angle at midstance (0.073 [95%CI 0.002–0.145], P = 0.045). SignificanceHip biomechanics during running did not display strong associations with symptom severity or cam morphology size in male football players with FAI syndrome who were still participating in training and match play. Future studies might consider investigating associations during tasks that utilise end range hip joint motion or require greater muscle forces.

Dynamic adjustment of submaximal effort soccer side-foot kicks

ABSTRACT We aimed to illustrate kicking leg dynamics during submaximal effort soccer side-foot kicks. Side-foot kicks with three effort levels (50, 75 and 100% effort levels based on maximal effort) of eight male university soccer players were captured (500 Hz) while initial ball velocities were monitored simultaneously. Systematic regulation in joint kinetics (angular impulses) was clearly demonstrated for hip flexion and knee extension moments thereby supporting the interpretation that the final foot velocity is controlled in a context of a planar, sequential segmental system. Out of the thigh-shank plane motion (hip external rotation moment) was also found to be systematically adjusted. Kinematic contributions of knee extension angular velocity to the final foot velocity increased significantly in the maximal effort while that of hip external rotation reduced significantly, coinciding with a more straightforward approach-run. The adjustable range of the foot-ball interaction was found to be rather smaller in side-foot kicks. However, significantly smaller ball/foot velocity ratios in the two submaximal conditions suggested ankle joint fixation was manipulated towards ball impact. Players and coaches ought to recognise that the intensities of side-foot kicks were regulated by the motions within and without the thigh-shank plane alongside several kinematic changes.

Model-based estimation of muscle and ACL forces during turning maneuvers in alpine skiing

In alpine skiing, estimation of the muscle forces and joint loads such as the forces in the ACL of the knee are essential to quantify the loading pattern of the skier during turning maneuvers. Since direct measurement of these forces is generally not feasible, non-invasive methods based on musculoskeletal modeling should be considered. In alpine skiing, however, muscle forces and ACL forces have not been analyzed during turning maneuvers due to the lack of three dimensional musculoskeletal models. In the present study, a three dimensional musculoskeletal skier model was successfully applied to track experimental data of a professional skier. During the turning maneuver, the primary activated muscles groups of the outside leg, bearing the highest loads, were the gluteus maximus, vastus lateralis as well as the medial and lateral hamstrings. The main function of these muscles was to generate the required hip extension and knee extension moments. The gluteus maximus was also the main contributor to the hip abduction moment when the hip was highly flexed. Furthermore, the lateral hamstrings and gluteus maximus contributed to the hip external rotation moment in addition to the quadratus femoris. Peak ACL forces reached 211 N on the outside leg with the main contribution in the frontal plane due to an external knee abduction moment. Sagittal plane contributions were low due to consistently high knee flexion (> 60^{circ }), substantial co-activation of the hamstrings and the ground reaction force pushing the anteriorly inclined tibia backwards with respect to the femur. In conclusion, the present musculoskeletal simulation model provides a detailed insight into the loading of a skier during turning maneuvers that might be used to analyze appropriate training loads or injury risk factors such as the speed or turn radius of the skier, changes of the equipment or neuromuscular control parameters.

Effects of load increase on lower extremity kinetic and kinematic variables in the back squat exercise.

Squats are one of the most widely used weight training methods worldwide, and the single most ubiquitous with regard to multi-joint resistance training. The objective of the present study was to investigate kinematic and kinetic changes in the lower extremities as a result of load increases during a back squat exercise, and to propose an association between back squats and lower extremity injuries. Eight individuals with experience of back squat training were recruited. The subjects performed back squats with loads of 25%, 50%, 100%, and 125% of their body weight. During the performance, the center of pressure (COP) sway; vertical center of mass (COM) velocity; joint moment; joint range of motion (ROM) of flexion/extension and adduction/abduction; and rotation of the ankle, knee, and hip joints were measured. The participants' lower extremity joint ROM, vertical COM velocity, and COP variability did not change significantly with changes in weight loading. However, the moments applied to the lower extremity joints differed according to changes in barbell weight. The moments of plantar flexion (f= 54.362, p< 0.001), dorsiflexion (f= 8.475, p< 0.001), knee flexion (f= 12.013, p< 0.001), knee extension (f= 8.581, p< 0.001), hip flexion (f= 5.111, p< 0.001), and hip extension (f= 11.053, p< 0.001) increased in the sagittal plane (flexion/extension). There was also a significant increase in ankle eversion (f= 5.612, p= 0.004), hip abduction (f= 3.242, p= 0.037), and adduction (f= 5.846, p= 0.003) in the frontal plane (adduction/abduction). Among the moment variables in the transverse plane (rotation), there were significant differences in ankle internal rotation (f= 7.043, p= 0.001) and hip external rotation (f= 11.070, p< 0.001). As the barbell load increased, posture and performance were maintained, but rotational moments of the joints differed. It is expected that the joint directions that showed significant differences in this study are likely to be vulnerable to the risk of injury when an excessive load is applied to the body. Examples include the hip adduction moment, hip external rotation moment, and ankle internal rotation moment, and apply regardless of the increase in the rotational moments of joints from load increases.

Greater Hip Moments in Rear-Foot-Elevated Split Squats Than in Conventional Back Squats With the Same Relative Intensity of Loads.

Arakawa, H, Mori, M, and Tanimoto, M. Greater hip moments in rear-foot-elevated split squats than in conventional back squats with the same relative intensity of loads. J Strength Cond Res 37(5): 1009-1016, 2023-Rear-foot-elevated split squat (RFESS) is often performed as an alternative to conventional double-leg back squat (DLBS). This study aimed to compare 3-dimensional joint kinetics of DLBS and RFESS using the same relative intensity of loads. Eight male college rugby players performed 3 repetitions of DLBS and RFESS at 10-repetition-maximum (RM) loading. Before testing, both exercises were incorporated into the subjects' training program with a progressive increase in loads for 4 months. A 3-dimensional optical motion capture system and force platform were used for data collection. The 3-dimensional moments at the knee and hip joints in each of the 3 axes were calculated based on the inverse dynamic procedure. p values < 0.05 were considered statistically significant. The hip extension moment was 44% greater in the RFESS than in the DLBS at the bottom position ( p < 0.01) and 47% greater for the peak value ( p < 0.01) on harmonic averages. The hip abduction and external rotation moments at the bottom position were also greater in the RFESS than in the DLBS. The findings suggest that the magnitude of hip extension moment per leg in DLBS tends to be restricted to less than that expected from the given strength level. In conclusion, the mechanical contribution of hip extensors per leg can be greater in RFESS than in DLBS when using respective 10RM loads, even if the absolute load is smaller and the trunk is more upright in RFESS.

The effect of fatigue on the ankle and knee kinematics and kinetics in moderately and highly trained healthy non-rearfoot runners

ABSTRACT The aim of this study was to compare selected ankle and knee kinematic and kinetic parameters before and after a prolonged exhaustive treadmill run between two groups of non-rearfoot footstrike pattern (NRFP) runners with different training volumes. Twenty-eight habitual NRFP runners were assigned to two groups based on their weekly training volume (Highly-trained (HT)/Moderately-trained (MT)). Participants underwent the VO2max test, and the exhaustive treadmill ran with biomechanical analysis at the beginning and the end. The two-way RMANOVA was used to assess differences between the groups and the phase of the run. A paired t-test was used for post-hoc analysis in case of significant interaction effect. Kinetic results showed significant group effect for ankle plantarflexion moment and hip external rotation moment (end-phase: both greater in MT group). Kinematic results showed significant group×phase interaction for ankle dorsiflexion angle (end-phase: greater in MT group) at initial contact (IC), peak knee flexion angle (end-phase: greater in MT group), and peak ankle eversion angle during the stance phase (end-phase: greater in HT group). Additionally, a group effect was found for knee flexion angle at IC (end-phase: greater in HT group). This study suggests that HT healthy NRFP runners may have less potential for increased biomechanical risk of AT overload during an exhaustive run.

The time-continuous association between turnout and axial joint moments in the competitive Irish dance ‘fly’ landing

ABSTRACT Turnout is a key technical and aesthetic element in competitive Irish dance involving external rotation of the lower limb and must be sustained during landings. ‘Forced’ turnout, aided by floor friction rather than active hip rotation, is likely to result in large internal rotation moments at the knee and ankle, which may increase the risk of injury. The aim of the current study was to establish the relationship between the hip and ankle external rotation vector field and maximum internal rotation moments of the ankle and knee. Thirteen (12 female) competitive Irish dancers performed 10 flys (common Irish dance leap) onto a force plate while being recorded by a ten-camera motion capture system. Time-continuous data were analysed over the duration of landing using statistical parametric mapping (SPM). A positive correlation (p < 0.05) was found between the hip-ankle turnout vector field and maximum ankle internal rotation moments throughout most of the landing. Post-hoc analyses showed that hip external rotation contributed the most to the maximum ankle internal rotation moment (p < 0.05). Increasing hip turnout during landing could reduce internal rotation moments, assuming hip turnout brings the thigh and foot axial orientation more in line with each other.

Is there a dose-response of medial wedge insoles on lower limb biomechanics in people with pronated feet during walking and running?

Although the effects of medial wedge insoles on lower limb biomechanics have been investigated, information about the effects of different magnitudes of medial posting is still lacking. What are the dose-response effects of medial wedge insoles with postings varying between 0 °, 3 °, 6 °, and 9 ° of inclination on the lower limb biomechanics during walking and running in individuals with pronated feet? Sixteen participants with an FPI ≥ 6 were recruited. Four arch-supported insole conditions with varying degrees of medial heel wedge were tested (0°, 3°, 6°, and 9°). A 3D motion analysis system with force plates was used to obtain the kinetics and kinematics of walking and running at self-selected speeds. To compare the ankle, knee, and hip angles and moments among conditions, a time series analysis was performed using Statistical Parametric Mapping (SPM). A reduction in ankle eversion angle was observed during walking for all insoles. For running, the 6° and 9° insoles decreased the ankle eversion angle during early stance and increased this angle during the propulsive phase. A decrease in ankle eversion moment was observed in walking and running for 6° and 9° insoles. An increase in knee adduction moment occurred in walking and running for all insoles. For hip, the 6° and 9° insoles showed, during walking, a decrease in hip adduction angle and an increase in hip adduction and external rotation moments. For most variables, statistical differences were found for a greater period across the stance phase as the medial wedge increased, except for ankle eversion moment and hip external rotation moment during walking. The biomechanical effects over the time series for many of the parameters increased with the addition of insole inclination, showing a dose-response effect of medial wedge insoles on the lower limb biomechanics during walking and running in adults with excessive foot pronation.

Neuromuscular Training Improves Self-Reported Function and Single-Leg Landing Hip Biomechanics in Athletes After Anterior Cruciate Ligament Reconstruction.

Background:Neuromuscular training (NMT) has been shown to attenuate high-risk biomechanics in uninjured athletes. At the time that athletes return to sport after anterior cruciate ligament (ACL) reconstruction (ACLR), they demonstrate hip biomechanical deficits associated with injury to the reconstructed knee versus the uninjured contralateral knee.Purpose:The primary purpose of the study was to examine whether an NMT program can improve single-leg drop (SLD) landing hip biomechanics for athletes after ACLR. Secondarily, we compared the posttraining SLD hip biomechanics of athletes after ACLR with a control group of athletes who also completed the NMT program.Study Design:Controlled laboratory study.Methods:A total of 18 ACLR and 10 uninjured athletes were recruited and completed a 12-session NMT program. A knee-specific questionnaire and biomechanics of an SLD task was evaluated for each athlete before and after NMT. Paired t tests were used to compare pre- and posttraining International Knee Documentation Committee (IKDC) scores. Repeated-measures analysis of variance (ANOVA) was performed to assess the main effects and interactions of testing session × limb for the ACLR athletes. A 2-way ANOVA was conducted to quantify the interactions and main effects of group × limb.Results:There was a significant increase (P = .03) in IKDC scores from pre- to posttraining. For the ACLR athletes, there was a significant session × limb interaction for hip external rotation moment (P = .02) and hip abduction angle (P = .013). Despite increases in hip external rotation moment, no significant changes from pre- to posttraining were observed for the involved limbs. No significant changes were observed for hip abduction angle of the involved limbs between training sessions. Significant main effects of session (P < .05) revealed that athletes landed with greater hip excursion, lower hip flexion moment, and lower ground-reaction force after training. The posttraining comparison between the ACLR and control groups found no significant group × limb interactions for any of the hip kinematic or kinetic variables. A significant main effect of group (P < .05) revealed that the ACLR athletes landed with greater hip flexion angle and hip external rotation moment.Conclusion:ACLR athletes demonstrated an improvement in SLD hip biomechanics and neuromuscular control after participating in an NMT program.Clinical Relevance:This evidence indicates a potential role for NMT to improve hip biomechanics during an SLD task so as to reduce ACL injury risk.

Field hockey sport-specific postures during unanticipated sidestepping: Implications for anterior cruciate ligament injury prevention

ABSTRACT Much research has investigated whole-body postures and associated knee joint loading during unanticipated sidestepping (UnSS). However, no research has considered sport-specific postures in field hockey. The purpose of this study was to investigate differences in trunk and lower limb angle and lower extremity joint moment waveforms during UnSS while holding a hockey stick in a flexed posture (HS-UnSS) and traditional UnSS. Additionally, we aimed to determine if differences in posture during HS-UnSS were associated with changes in knee joint moments. Twelve elite female field hockey athletes underwent 3D motion analysis during UnSS and HS-UnSS. Athletes increased trunk (0–100% of stance phase, hip (0–15%), knee (12–29%; 39–59%; 78–100%) and ankle (41–57%) flexion angles, and increased hip flexion (19–24%; 42–45%; 75–84%) and external rotation moments (75–80%) during HS-UnSS compared with UnSS (p < 0.05). Flexed postures observed during HS-UnSS did not influence knee flexion and valgus moments when compared with UnSS (p > 0.05), however knee external rotation moments reduced. Changes in trunk flexion were positively associated with peak knee internal rotation moments from UnSS to HS-UnSS (r = 0.779, p = 0.005). These findings indicate that field hockey players sidestep with significantly different techniques when holding a hockey stick, which should be considered in injury prevention training protocols.

Breast Support Alters Knee Joint Biomechanics During A Landing Task.

Females have a greater rate of traumatic knee injuries than male athletes. Trunk position has been shown to affect knee joint biomechanics during a landing task. Given the position of breast tissue, insufficiently supported breasts may also alter knee joint biomechanics. However, no previous research has investigated the effect of breast tissue or support on knee joint biomechanics during landing. PURPOSE: to determine the effect of breast support on knee and hip joint kinetics during a landing task. METHODS: Fifteen female athletes performed five step-off landings from a height of 40 cm in each of three bra support conditions: control (CON), low support (LOW) and high support (HIGH). 3D kinematics and ground reaction forces (GRFs) were simultaneously recorded using a 9-camera motion capture system (240 Hz,) and pair of force platforms (1200 Hz,)..) was used to calculate knee and hip joint angles and moments. Custom software (was used to determine peak joint angles and moments. Repeated measures ANOVAs with Tukey’s post-hoc analyses were used to compare mean knee and hip joint kinetics. RESULTS: No differences in peak knee abduction moments were observed, though peak knee external rotation moments were smaller in the LOW compared to CON (p = 0.007) and HIGH conditions (p = 0.013). No differences were observed between CON and HIGH (p = 0.423). No differences were observed in peak hip abduction moment or peak hip external rotation moment. CONCLUSIONS: These findings indicate that knee joint biomechanics during a landing task are affected by breast support. The current study did not address the role of trunk orientation or differences in breast size amongst participants. Future research should address the role of breast motion on trunk kinematics and kinetics.Table 1: Mean knee and hip joint moments in the CON, LOW and HIGH support conditions.

Lower-Limb Biomechanics in Football Players with and without Hip-related Pain.

This study aimed to evaluate the differences in lower-limb biomechanics between adult subelite competitive football players with and without hip-related pain during two contrasting tasks-walking and single-leg drop jump (SLDJ)-and to determine whether potential differences, if present, are sex dependent. Eighty-eight football players with hip-related pain (23 women, 65 men) and 30 asymptomatic control football players (13 women, 17 men) who were currently participating in competitive sport were recruited. Biomechanical data were collected for the stance phase of walking and SLDJ. Pelvis, hip, knee, and ankle angles, as well as the impulse of the external joint moments, were calculated. Differences between groups and sex-specific effects were calculated using linear regression models. Compared with their asymptomatic counterparts, football players with hip-related pain displayed a lower average pelvic drop angle during walking (P = 0.03) and a greater average pelvic hike angle during SLDJ (P < 0.05). Men with hip-related pain displayed a smaller total range of motion (excursion) for the transverse plane pelvis angle (P = 0.03) and a smaller impulse of the hip external rotation moment (P < 0.01) during walking compared with asymptomatic men. Women with hip-related pain displayed a greater total range of motion (excursion) for the sagittal plane knee angle (P = 0.01) during walking compared with asymptomatic women. Overall, few differences were observed in lower-limb biomechanics between football players with and without hip-related pain, irrespective of the task. This outcome suggests that, despite the presence of symptoms, impairments in lower-limb biomechanics during function do not appear to be a prominent feature of people with hip-related pain who are still participating in sport.

Squat and gait biomechanics 6 months following hip arthroscopy for femoroacetabular impingement syndrome.

The purpose of this study was to (i) assess whether squat and gait biomechanical measures improve in patients with femoroacetabular impingement syndrome (FAIS) 6 months after surgery compared to pre-operative measures and (ii) compare biomechanical properties to controls without FAIS. In this prospective study, biomechanical data during a double leg squat task and gait for 15 FAIS patients and 9 controls were collected using three-dimensional motion analysis. Data were collected in the FAIS group at two-time points, pre-operatively and 6-month post-operatively following arthroscopic hip surgery, and at a single time point for the healthy controls. Independent sample’s t-test were used to compare the FAIS group to the controls, and paired samples t-test were used to determine within-group differences before and after hip arthroscopy in the FAIS group. The results indicated that there were significant within-group increases for sagittal plane moment rate during the double leg squat task (P = 0.009) between the pre-operative and post-operative time points for the FAIS group. Between-group differences showed that FAIS patients pre-operatively exhibit slower squat velocities during the descent (P = 0.005) and ascent phase (P = 0.012) of a double leg squat when compared healthy controls. Reduced hip external rotation moments during gait (P = 0.02) were also found between FAIS patients pre-operatively and controls. In conclusion, alterations in hip biomechanics are present before surgery for FAIS when compared to healthy controls, and joint mechanics change 6 months after surgery. However, the biomechanical differences during a double leg squat and gait were minimal.

Sex affects gait adaptations after exercise in individuals with anterior cruciate ligament reconstruction

BackgroundOsteoarthritis after anterior cruciate ligament reconstruction has been linked with changes in gait. Individuals with reconstruction demonstrate gait changes after exercise, however there is no information on altered gait after exercise based on sex. The purpose of this study was to examine the association of sex on changes in running gait after exercise in individuals with reconstruction compared to healthy. MethodsForty females (22 reconstructed) and 22 men (11 reconstructed) ran before and after exercise. Triplanar lower extremity kinematics and kinetics were measured on the involved limb. Data were reduced to 0–100% of gait. Change scores were calculated for each 1% with 90% confidence intervals. Mean differences were calculated for all significant differences. FindingsAfter exercise, females with reconstruction increased knee valgus (1.81°), knee external rotation (2.02°), lateral trunk flexion (1.24°) and trunk rotation (2.15°) compared to healthy females. Females with reconstruction increased knee extension moment (0.07 Nm/kg), knee abduction moment (0.08 Nm/kg), hip extension moment (0.14 Nm/kg) and hip internal rotation moment (0.04 Nm/kg) compared to healthy females. After exercise, males with reconstruction decreased knee varus (−4.83°), hip adduction (−1.99°), and hip internal rotation (−4.44°), however increased lateral trunk flexion (1.94°) compared to healthy males. Males with reconstruction increased knee extension moment (0.07 Nm/kg), knee adduction moment (0.31 Nm/kg), knee internal rotation moment (0.13 Nm/kg), hip flexion moment (0.17 Nm/kg), and hip external rotation moment (0.05 Nm/kg) compared to healthy males. InterpretationMales with reconstruction increased hip loading while women with reconstruction increased trunk motion post-exercise. Sex should be considered when evaluating response to exercise after reconstruction.

The effects of intensive dietary weight loss and exercise on gait in overweight and obese adults with knee osteoarthritis. The Intensive Diet and Exercise for Arthritis (IDEA) trial

The Intensive Diet and Exercise for Arthritis (IDEA) trial was an 18-month randomized controlled trial that enrolled 454 overweight and obese older adults with symptomatic and radiographic knee osteoarthritis (OA). Participants were randomized to either exercise (E), intensive diet-induced weight loss (D), or intensive diet-induced weight loss plus exercise (D + E) interventions. We previously reported that the clinical benefits of D + E were significantly greater than with either intervention alone (e.g., greater pain reduction, and better function, mobility, and health-related quality of life). We now test the hypothesis that D + E has greater overall benefit on gait mechanics compared to either intervention alone. Knee joint loading was analyzed using inverse dynamics and musculoskeletal modeling. Analysis of covariance determined the interventions’ effects on gait. The D + E group walked significantly faster at 18-month follow-up (1.35 m s−1) than E (1.29 m s−1, p = 0.0004) and D (1.31 m s−1, p = 0.0007). Tibiofemoral compressive impulse was significantly lower (p = 0.0007) in D (1069 N s) and D + E (1054 N s) compared to E (1130 N s). D had significantly lower peak hip external rotation moment (p = 0.01), hip abduction moment (p = 0.0003), and peak hip power production (p = 0.016) compared with E. Peak ankle plantar flexion moment was significantly less (p < 0.0001) in the two diet groups compared with E. There also was a significant dose-response to weight loss; participants that lost >10% of baseline body weight had significantly (p = 0.0001) lower resultant knee forces and lower muscle (quadriceps, hamstring, and gastrocnemius) forces than participants that had less weight loss. Compared to E, D produces significant load reductions at the hip, knee, and ankle; combining D with E attenuates these reductions, but most remain significantly better than with E alone.

Changes in running kinematics and kinetics after a 12-week running program for beginners

ABSTRACT The effect of running training on running kinematics and kinetics in novice runners has not yet been investigated. Previous studies have shown that novice runners are less economical and more prone to injury compared to well-trained runners. Since running economy (RE) and running injury risk have been associated with biomechanical variables that may be trainable, the purpose of this study was to determine the effect of a 12-week training program for beginners on running kinematics and kinetics. It was hypothesised that participants would evolve towards running kinematics and kinetics that have previously been associated with better RE and lower injury risk. 27 participants underwent a full-body, three-dimensional running analysis before and after a 12-week running program. Outcome variables included peak joint angles, joint moments, and ground reaction forces (GRF) in three planes. After training, hip external rotation moment increased significantly with 0.01 Nm/kg. Peak vertical GRF decreased with 0.9 N/kg (4.05%). There were no significant changes in peak joint angles. In conclusion, results show that a 12-week running program for beginners aimed to increase running endurance does not lead to changes in running kinematics or kinetics that have previously been associated with better RE and lower injury risk.

Effect of 16-week corrective training program on three dimensional joint moments of the dominant and non-dominant lower limbs during gait in children with genu varus deformity

Summary Context Proper treatment of lower limbs alignment in children may prevent the progression of pathologies. However, this is not evaluated from a scientific view-point. Objective The purpose of this study was to evaluate the effects of a 16-week Corrective Exercise Continuum (CEC) programming strategy on three dimensional joint moments of dominant and non-dominant lower limbs during walking. Design Randomized control trials. Setting Sports biomechanics laboratory. Participants Twenty eight male children with genu varus and with permission of their parents were volunteered to participate in this study. They were randomly divided in two equal-sized groups (experimental and control). Intervention Corrective Exercise Continuum (CEC) programming strategy. Main Outcome Measures Data acquisition was carried out using six infrared motion analysis cameras (Vicon motion Systems, Oxford, UK) and two force platforms (Kistler AG, Winterthur, Switzerland). The joint moments of the ankle, knee, and hip of the both lower extremities were calculated using inverse dynamics approach. Results The results indicated that CEC decreased the peak knee internal rotation moment (P Conclusions Performing CEC could reduce excessive knee internal rotation moment as well as hip external rotation moment identified as two key risk factors for medial knee osteoarthritis. Therefore, it would be recommended for children with genu varus, in that it can prevent and slow joint degeneration in adulthood.

Amputee Locomotion: Joint Moment Adaptations to Running Speed Using Running-Specific Prostheses after Unilateral Transtibial Amputation.

The objective of this study was to investigate three-dimensional lower extremity joint moment differences between limbs and speed influences on these differences in individuals with lower extremity amputations using running-specific prostheses. Eight individuals with unilateral transtibial amputations and 8 control subjects with no amputations ran overground at three constant velocities (2.5, 3.0, and 3.5 m/sec). A 2 × 2 × 3 (group × leg × speed) repeated-measures analysis of variance with Bonferroni adjustments determined statistical significance. The prosthetic limb generated significantly greater peak ankle plantarflexion moments and smaller peak ankle varus, knee stance extension, knee swing flexion, knee internal rotation, hip stance flexion, hip swing flexion, hip swing extension, hip valgus, and hip external rotation moments than the intact limb did. The intact limb had greater peak hip external rotation moments than control limbs did, but all other peak moments were similar between these limbs. Increases in peak hip stance and knee swing flexion moments associated with speed were greater in the intact limb than in the prosthetic limb. Individuals with amputation relied on the intact limb more than the prosthetic limb to run at a particular speed when wearing running-specific prostheses, but the intact joints were not overloaded relative to the control limbs.