Peak Hip Extension Angle 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.

Trunk orthosis with joints providing resistive force improves dynamic sagittal alignment in postoperative patients with lumbar spinal stenosis

This study aimed to determine whether a trunk orthosis with joints providing resistive force (TORF) modifies sagittal malalignment during level walking in patients with lumbar spinal stenosis (LSS). Fifteen patients, 6 months after undergoing surgery for LSS, performed level walking at a self-selected speed while wearing a TORF. Dynamic sagittal alignment, including sagittal vertical axis, lumbar lordosis, and pelvic tilt, and spatiotemporal data as well as lower limb kinematic and kinetic data were recorded using a three-dimensional motion analysis system and six force plates. Statistical analysis was performed to compare these data with and without the TORF, respectively. Compared to the condition without the TORF, the use of the TORF significantly decreased positive sagittal vertical axis (p < 0.05) and increased the lumbar lordosis and pelvic tilt (p < 0.05). Peak hip flexion angle and extension moment during loading response (LR) significantly increased (p < 0.05), and peak hip extension angle and flexion moment during PS statistically decreased (p < 0.05). There was no difference in spatiotemporal data between the two conditions. Our findings suggest that TORF may modify the dynamic sagittal global alignment and lower limb kinematic and kinetics in postoperative LSS patients during level walking.

A portable visual biofeedback device can accurately measure and improve hip extension angle in individuals post-stroke

BackgroundVisual biofeedback has shown success in improving gait mechanics in individuals post-stroke but has typically been restricted to use on a treadmill or a short walkway. Using real-time visual biofeedback during overground walking could increase the ease of clinical translation of this method. The objective was to investigate the reliability of a real-time hip extension feedback device during unconstrained, overground walking. We hypothesized that the peak hip extension angle outcome of our device would be comparable to peak hip extension angle measured from a common motion capture system. In addition, we hypothesized that individuals post-stroke would increase their hip extension angle after a single walking bout with visual biofeedback of their hip extension angle. MethodsFourteen individuals with chronic stroke walked for one six-minute walking bout with the visual biofeedback device. Before (pre-training) and after (post-training) the feedback walking bout, participants walked in a straight line at their self-selected speed for at least five steps per foot. FindingsOur device was reliable in measuring peak hip extension angle when compared to 3D motion capture equipment (R2 = 0.99). Individuals increased their hip extension angle after one session with the visual biofeedback (+2.886 ± 2.189 deg) compared to a control walking bout (+1.550 ± 1.629 deg) (Z = −2.103, p = 0.035). InterpretationOur novel and inexpensive biofeedback method may provide benefit for individuals post-stroke and expand the possibilities for feedback in rehabilitation.

Is Maximum Available Hip Extension Range of Motion of the Residual Limb Reached During Passive Prone Lying in the Acute Stage After Dysvascular Transtibial Amputation?

ABSTRACT Introduction Individuals after a transtibial amputation (TTA) are at risk to develop a hip flexion contracture, which may adversely affect future ambulation with a prosthesis. Although patients have traditionally been advised to lie prone to maintain or improve hip extension, compensatory pelvic tilting may occur in prone lying (PL). We sought to compare hip extension range of motion (ROM) in PL to the modified Thomas test (MTT) position, because research implies that, in the MTT, patients are better able to control for compensatory pelvic tilting. We hypothesized that individuals after a TTA would have a greater peak hip extension angle in the MTT position compared with the PL position. Methods Ten individuals after a dysvascular TTA, mean age of 60 ± 8.42 years, participated in this study. The same physical therapist marked the femur and pelvis for goniometric measurement of peak hip extension angle by 12 raters blinded to each other's measurements. The markers remained unchanged as six raters measured all participants in PL and six different raters measured all participants in the MTT position. Results and Discussion The intraclass correlation (ICC) indicated high interrater reliability between the raters for the PL and MTT positions (ICC = 0.985 for PL and 0.976 for MTT). The average peak hip extension angle in PL was −14.0° ± 13.3°, standard error of mean = 4.3°; and in the MTT position was −8.6° ± 15.3°, standard error of mean = 4.8° (the negative mean connotes that, on average, participants did not have hip extension to neutral for either condition). We found a mean of 5.4° ± 6.6° more hip extension ROM for the MTT position compared with PL (P = 0.028). Conclusions Our findings show that, on average, patients after a TTA have significantly greater peak hip extension angle in the MTT position compared with the PL position. Thus, passive PL may not be as effective of a stretching position for preventing a hip flexion contracture after a TTA, because PL does not always extend the patient's hip to its maximum available ROM, due to the reduced ability to control the pelvis from tilting anteriorly. Clinical Relevance Adequate hip flexor length is positively correlated with gait parameters, which include increased velocity and step length in people using a prosthesis after transtibial amputation. This study implies that the MTT position may be a better method for improving and maintaining hip flexor length over the traditional strategy of passive PL.

Effects of age and gender on spatiotemporal and kinematic gait parameters in older adults

Purpose: Gait changes are more prominently observed in older adults than in young adults, especially in kinematics of lower extremities and trunk. These changes can result in incidental falls during gait, possibly leading to inability to perform activities of daily living independently. This study aimed to investigate the effect of gender and age on gait changes, such as spatiotemporal parameters and peak joint angles in lower extremities and trunk during gait. Methods: A total of 387 participants (223 women) were included. The Microsoft Kinect V2 sensor was used to obtain the coordinate data of lower extremities and trunk during gait. The coordinate data obtained were processed using the software. Walking speed, stride length, stride time and cadence were calculated as spatiotemporal variables of walking. Forward trunk tilt angle (FTT), hip flexion and extension, and knee flexion and extension were measured as peak angles during one-gait cycle. Participants were categorized into five groups according to age by five years. Multivariate analysis of variance was performed to compare the spatiotemporal and kinematical data among groups. Results: Significant differences among age groups were noted in terms of the walking speed and stride length. Significant differences were also observed in the FTT and hip extension angle. Conclusions: Increased gait changes, increased peak FTT and decreased peak hip extension angle were observed with an increase of age. These altered symptoms may contribute to the screening of older adults at risk of declined physical function at an early stage

Biomechanical analysis of an unpowered hip flexion orthosis on individuals with and without multiple sclerosis

BackgroundGait impairment is a common complication of multiple sclerosis (MS). Gait limitations such as limited hip flexion, foot drop, and knee hyperextension often require external devices like crutches, canes, and orthoses. The effects of mobility-assistive technologies (MATs) prescribed to people with MS are not well understood, and current devices do not cater to the specific needs of these individuals. To address this, a passive unilateral hip flexion-assisting orthosis (HFO) was developed that uses resistance bands spanning the hip joint to redirect energy in the gait cycle. The purpose of this study was to investigate the short-term effects of the HFO on gait mechanics and muscle activation for people with and without MS. We hypothesized that (1) hip flexion would increase in the limb wearing the device, and (2) that muscle activity would increase in hip extensors, and decrease in hip flexors and plantar flexors.MethodsFive healthy subjects and five subjects with MS walked for minute-long sessions with the device using three different levels of band stiffness. We analyzed peak hip flexion and extension angles, lower limb joint work, and muscle activity in eight muscles on the lower limbs and trunk. Single-subjects analysis was used due to inter-subject variability.ResultsFor subjects with MS, the HFO caused an increase in peak hip flexion angle and a decrease in peak hip extension angle, confirming our first hypothesis. Healthy subjects showed less pronounced kinematic changes when using the device. Power generated at the hip was increased in most subjects while using the HFO. The second hypothesis was not confirmed, as muscle activity showed inconsistent results, however several subjects demonstrated increased hip extensor and trunk muscle activity with the HFO.ConclusionsThis exploratory study showed that the HFO was well-tolerated by healthy subjects and subjects with MS, and that it promoted more normative kinematics at the hip for those with MS. Future studies with longer exposure to the HFO and personalized assistance parameters are needed to understand the efficacy of the HFO for mobility assistance and rehabilitation for people with MS.

Effects of unweighting on gait kinematics during walking on a lower-body positive-pressure treadmill in patients with hip osteoarthritis

BackgroundHip osteoarthritis (OA) is a musculoskeletal condition that makes walking difficult due to pain induced by weight-bearing activities. Treadmills that support the body weight (BW) reduce the load on the lower limbs, and those equipped with a lower-body positive-pressure (LBPP) device, developed as a new method for unweighting, significantly reduce pain in patients with knee OA. However, the effects of unweighting on gait kinematics remain unclear in patients with hip OA. Therefore, we investigated the effects of unweighting on kinematics in patients with hip OA during walking on a treadmill equipped with an LBPP device.MethodsA total of 15 women with hip OA and 15 age-matched female controls wore a three-dimensional (3-D) motion analysis system and walked at a self-selected speed on the LBPP treadmill. Data regarding self-reported hip pain using a numeric rating scale (NRS) in which the scores 0 and 10 represented no pain and the worst pain, respectively, under three different BW conditions (100, 75, and 50%) were collected. Moreover, 3-D peak joint angles during gait under each condition were calculated and compared.ResultsIn the hip OA group, the NRS pain scores at 50 and 75% BW conditions significantly decreased compared with that at 100% BW condition (50%, P = 0.002; 75%, P = 0.026), and the peak hip extension angle decreased compared with that in the healthy controls (P = 0.044). In both groups, unweighting significantly decreased the peak hip (P < 0.001) and knee (P < 0.001) flexion angles and increased the peak ankle plantar flexion angle (P < 0.001) during walking.ConclusionsUnweighting by the LBPP treadmill decreased pain in the hip OA group but did not drastically alter the gait kinematics compared with that in the control group. Therefore, regarding the use of the LBPP treadmill for patients with hip OA, clinicians should consider the benefits of pain reduction rather than the kinematic changes.

Racial differences in gait mechanics

The effect of race has rarely been investigated in biomechanics studies despite racial health disparities in the incidence of musculoskeletal injuries and disease, hindering both treatment and assessment of rehabilitation. The purpose of this study was to test the hypothesis that racial differences in gait mechanics exist between African Americans (AA) and white Americans (WA). Ninety-two participants (18–30 years old) were recruited with equal numbers in each racial group and sex. Self-selected walking speed was measured for each participant. 3D motion capture and force plate data were recorded during 7 walking trials at regular and fast set speeds. Step length, step width, peak vertical ground reaction force, peak hip extension, peak knee flexion, and peak ankle plantarflexion were computed for all trials at both set speeds. Multivariate and post-hoc univariate ANOVA models were fit to determine main and interaction effects of sex and race (SPSS V26, α = 0.05). Self-selected walking speed was slower in AA (p = 0.004, ƞp2 = 0.088). No significant interactions between race and sex were identified. Males took longer steps (regular: p < 0.001, ƞp2 = 0.288, fast: p < 0.001, ƞp2 = 0.193) and had larger peak knee flexion (regular: p = 0.007, ƞp2 = 0.081, fast: p < 0.001, ƞp2 = 0.188) and ankle plantarflexion angles (regular: p = 0.050, ƞp2 = 0.044, fast: p = 0.049, ƞp2 = 0.044). Peak ankle plantarflexion angle (regular: p = 0.012, ƞp2 = 0.071, fast: p < 0.001, ƞp2 = 0.137) and peak hip extension angle during fast walking (p = 0.007, ƞp2 = 0.083) were smaller in AA. Equivalency in gait measures between racial groups should not be assumed. Racially diverse study samples should be prioritized in the development of future research and individualized treatment protocols.

GASTROCNEMIUS TIGHTNESS AFFECTS HIP AND PELVIC MOVEMENT IN GAIT

The passive extensibility of skeletal muscles is an important health-related component of physical fitness. Tight gastrocnemius is a common orthopedic problem and frequently leads to overuse injuries of the lower extremity. Moreover, gastrocnemius tightness is commonly associated with lower back pain. Previous studies have reported that tight gastrocnemius results in kinematic and kinetic deviations of the ankle and knee during gait and a greater hip flexion at the moment of maximal ankle dorsiflexion. Accordingly, this study performs an experimental investigation into the effects of tight gastrocnemius on the hip and pelvic movements in gait. Sixteen subjects with tight gastrocnemius (defined as [Formula: see text] of ankle dorsiflexion with knee extended) and 16 healthy individuals matched by age and gender participated in the study. The three-dimensional angles of the hip and pelvis and moments of the hip were obtained for both groups during the stance phase of gait using force plates and a motion analysis system. Compared with the control group, the peak hip flexion angle is significantly higher in the tight group ([Formula: see text]), while the peak hip extension angle is significantly lower ([Formula: see text]). Moreover, the peak pelvic anterior tilt is significantly higher than that of the control group ([Formula: see text]), while the peak pelvic posterior tilt is significantly lower ([Formula: see text]). Finally, the peak extensor moment of the tight group is significantly higher than that of the control group ([Formula: see text]), while the peak flexor moment is significantly lower ([Formula: see text]). The results confirm that tight gastrocnemius leads to changes in the three-dimensional hip and pelvic angles and hip moments during gait. Disturbance of the hip and pelvic movement is thus a critical clinical consideration when evaluating soft tissue injuries in patients with tight gastrocnemius.

Hybrid Assistive Limb improves restricted hip extension after total hip arthroplasty

ABSTRACT The Hybrid Assistive Limb (HAL) was developed as an exoskeleton robot that supports gait training. The purpose of this study was to assess the usefulness of training using the HAL after total hip arthroplasty (THA). We targeted 16 consecutive patients who underwent THA via the posterior approach. We randomized patients to the HAL group (8 hips), in which the HAL was used as part of physical therapy, or the control group (8 hips), in which only typical physical therapy was performed. Gait analysis was performed before and after surgery, and comparisons were made between the two groups. We evaluated the single support time (%), double support time (%), cadence (steps/min), velocity (cm/s), stride length (cm), and anteroposterior and lateral variability, and assessed the hip and knee joint range of motion in the sagittal plane. The results showed improvements in the hip extension angle and other gait parameters in the HAL group. Among gait-related problems after THA, a decreased peak hip extension angle is reported to be a significant factor that affects gait disability. This study revealed that HAL usage after THA seems to be a useful method to obtain sufficient extension angle.

External loading alters lower extremity kinetics, kinematics, and muscle activity in a distribution-specific manner during the transition from stair descent to level walking

BackgroundExcess body mass is thought to be a major cause of altered biomechanics in obesity, but the effects of body mass distribution in biomechanics during daily living tasks are unknown. The purpose of this study was to determine how increasing body mass centrally and peripherally affects lower extremity kinematics, kinetics, and muscle activation when transitioning from stair descent to level gait. MethodsFifteen normal weight volunteers descended a staircase at a self-selected pace under unloaded, centrally loaded, and peripherally loaded conditions. Spatial-temporal gait characteristics and lower extremity joint kinematics, kinetics, and mean electromyography amplitude were calculated using 3D motion analysis. FindingsBoth central and peripheral loading reduced gait velocity. Peripheral loading increased time spent in stance phase, increased step width, and reduced step length. At the hip joint, peripheral loading reduced peak hip extension and adduction angle. Conversely, central loading reduced peak hip flexor moment. Both central and peripheral loading increased peak knee flexion angle, but only peripheral loading increased peak knee extensor moment. Central and peripheral loading increased mean electromyography amplitude of the medial gastrocnemius, but only peripheral loading increased mean electromyography amplitude of the semitendinosus and the vastus medialis. InterpretationIncreasing mass centrally and peripherally differently affects spatial-temporal gait characteristics and lower extremity joint kinematics, kinetics, and electromyography when transitioning from stair descent to level gait. Body mass distribution may be an important factor for obesity-induced biomechanical alterations and should be considered when developing biomechanical models of obesity.

Sub-elite Football Players With Hip-Related Groin Pain and a Positive Flexion, Adduction, and Internal Rotation Test Exhibit Distinct Biomechanical Differences Compared With the Asymptomatic Side.

Background Hip-related groin pain is common in sub-elite football players and may be associated with altered hip biomechanics. Objectives To compare the hip biomechanics, bony hip morphology associated with femoroacetabular impingement (FAI) syndrome, and hip strength and range of motion (ROM) between the symptomatic and asymptomatic limbs of sub-elite football players with unilateral hip-related groin pain and a positive flexion, adduction, and internal rotation (FADIR) test. Methods Fifteen sub-elite football (soccer) players with unilateral hip-related groin pain and a positive FADIR test were recruited for this observational cross-sectional study. Three-dimensional motion analysis and ground reaction force data were recorded for walking and a single-leg drop-jump (SLDJ) task. Participants also underwent a standard anterior-posterior hip radiograph and hip strength and ROM assessment. Between-limb differences were assessed using paired t tests or Wilcoxon signed-rank tests. Results The symptomatic limb displayed a smaller peak hip extension angle (P = .01) and a lower peak hip adduction moment (P = .03) compared with the asymptomatic limb during the stance phase of walking. Additionally, during the SLDJ, the symptomatic limb demonstrated less total sagittal plane ROM (P = .04). The symptomatic limb also demonstrated less external rotation ROM (P = .03). However, no differences were found between limbs for bony hip morphology associated with FAI syndrome or hip strength. Conclusion This study found between-limb asymmetries in low- and high-impact functional tasks, such as walking and an SLDJ, in football players with unilateral hip-related groin pain. Despite unilateral pain, bony morphology associated with FAI syndrome did not differ between limbs. J Orthop Sports Phys Ther 2018;48(7):584-593. Epub 8 May 2018. doi:10.2519/jospt.2018.7910.

Analyzing the effect of an arch support functional insole on walking and jogging in young, healthy females.

The aim of this study was to explore the effectiveness of arch support functional insoles to prevent metatarsalgia. Twenty-five healthy females participated in the study. A Vicon motion capture system was used to collect kinematics data of the lower limb. An AMTI force plate was used to record the vertical ground reaction force (GRF), and the Novel Pedar-X System was used to measure foot pressure while subjects wore normal insoles or functional insoles with an arch support during walking and jogging. With the arch support functional insoles, the first metatarsal (FM) region's contact area was increased and the peak pressure and time-pressure integral of the FM and second and third metatarsal (SATM) were areas decreased. This suggests a lower risk of longitude stress injuries in these areas. The ankle dorsiflexion angle of jogging with the 'arch support functional insoles' (RF) and walking with the 'arch support functional insoles' (WF) were significantly increased at initial contact and the knee and hip flexion angle of RF and WF were reduced. The peak hip extension angle of WF and RF also declined. The vertical loading rate of RF was lower, which would be beneficial in reducing the risk of lower limb injuries during jogging. The results demonstrate that arch support functional insoles can be used effectively to prevent and decrease pain and promote a suitable weight-bearing pattern in the foot for promoting the health of young females.

Effects of High- and Low-Velocity Resistance Training on Gait Kinematics and Kinetics in Individuals with Hip Osteoarthritis: A Randomized Controlled Trial.

The aim of this study was to investigate the effects of high-velocity (HV) and low-velocity (LV) resistance training on gait kinematics and kinetics in patients with hip osteoarthritis. This was a single-blind, randomized controlled trial. Forty-six women with hip osteoarthritis were randomly allocated to the HV (n = 23) or LV (n = 23) training group. The participants underwent an 8-week home-based the HV or LV resistance-training program, involving the hip and knee muscles. Outcome measures included gait kinematics and kinetics using 3-dimensional analyses, muscle strength and power, the Harris Hip Score, and hip pain using the visual analog scale. There was no significant difference in changes for any of the outcome measures between groups. After the training session, muscle power, walking speed, and cadence significantly increased only in the HV group, whereas stride length and the peak hip extension angle during gait significantly increased, and pain on the visual analog scale and the peak ankle dorsiflexion moment during gait significantly decreased only in the LV group. Muscle strength and Harris Hip Score significantly increased in both groups. The results of this study may indicate that the potential effect of resistance training on abnormal gait pattern depends on movement velocities during training.

The modified Thomas test is not a valid measure of hip extension unless pelvic tilt is controlled.

The modified Thomas test was developed to assess the presence of hip flexion contracture and to measure hip extensibility. Despite its widespread use, to the authors’ knowledge, its criterion reference validity has not yet been investigated. The purpose of this study was to assess the criterion reference validity of the modified Thomas test for measuring peak hip extension angle and hip extension deficits, as defined by the hip not being able to extend to 0º, or neutral. Twenty-nine healthy college students (age = 22.00 ± 3.80 years; height = 1.71 ± 0.09 m; body mass = 70.00 ± 15.60 kg) were recruited for this study. Bland–Altman plots revealed poor validity for the modified Thomas test’s ability to measure hip extension, which could not be explained by differences in hip flexion ability alone. The modified Thomas test displayed a sensitivity of 31.82% (95% CI [13.86–54.87]) and a specificity of 57.14% (95% CI [18.41–90.10]) for testing hip extension deficits. It appears, however, that by controlling pelvic tilt, much of this variance can be accounted for (r = 0.98). When pelvic tilt is not controlled, the modified Thomas test displays poor criterion reference validity and, as per previous studies, poor reliability. However, when pelvic tilt is controlled, the modified Thomas test appears to be a valid test for evaluating peak hip extension angle.

Factors associated with restricted hip extension during gait in women after total hip arthroplasty.

A decreased peak hip extension angle in the late stance phase is a major gait abnormality in patients with THA. The purpose of this study was to determine the relationship between peak hip extension angle during gait and functional impairments such as muscle weakness and the limitation in joint range of motion and to identify the clinical factors influencing peak hip extension angle during gait. 67 female volunteers with THA were examined. Biomechanical gait analysis was performed to measure peak hip extension angle during gait. Maximal isometric strength of the hip and knee, passive hip extension range of motion, leg length discrepancy, and hip pain were assessed. Peak hip extension angle during gait significantly correlated with passive hip extension range of motion (r = 0.259), hip pain (r = -0.264), isometric strengths of the hip musculature (r = 0.278-0.491), and knee extensor (r = 0.386). Stepwise multiple regression analysis revealed that hip abductor torque (β = 0.355, P = 0.001), hip pain (β = -0.353, P = 0.001), and passive hip extension range of motion (β = 0.258, P = 0.011) were significant contributors to peak hip extension angle during gait (R2 = 0.408). Our findings suggest that THA rehabilitation aimed at improving gait ability should focus on strengthening the hip abductors, controlling hip pain and increasing range of motion of hip extension.

Effect of posture on hip angles and moments during gait

Anterior hip pain is common in young, active adults. Clinically, we have noted that patients with anterior hip pain often walk in a swayback posture, and that their pain is reduced when the posture is corrected. The purpose of this study was to investigate a potential mechanism for the reduction in pain by testing the effect of posture on movement patterns and internal moments during gait in healthy subjects. Fifteen subjects were instructed to walk while maintaining three postures: 1) natural, 2) swayback, and 3) forward flexed. Kinematic and force data were collected using a motion capture system and a force plate. Walking in the swayback posture resulted in a higher peak hip extension angle, hip flexor moment and hip flexion angular impulse compared to natural posture. In contrast, walking in a forward flexed posture resulted in a decreased hip extension angle and decreased hip flexion angular impulse. Based on these results, walking in a swayback posture may result in increased forces required of the anterior hip structures, potentially contributing to anterior hip pain. This study provides a potential biomechanical mechanism for clinical observations that posture correction in patients with hip pain is beneficial.

Joint kinematics and kinetics during walking and running in 32 patients with hip dysplasia 1 year after periacetabular osteotomy

Background and purpose — Hip dysplasia can be treated with periacetabular osteotomy (PAO). We compared joint angles and joint moments during walking and running in young adults with hip dysplasia prior to and 6 and 12 months after PAO with those in healthy controls.Patients and methods — Joint kinematics and kinetics were recorded using a 3-D motion capture system. The pre- and postoperative gait characteristics quantified as the peak hip extension angle and the peak joint moment of hip flexion were compared in 23 patients with hip dysplasia (18–53 years old). Similarly, the gait patterns of the patients were compared with those of 32 controls (18–54 years old).Results — During walking, the peak hip extension angle and the peak hip flexion moment were significantly smaller at baseline in the patients than in the healthy controls. The peak hip flexion moment increased 6 and 12 months after PAO relative to baseline during walking, and 6 months after PAO relative to baseline during running. For running, the improvement did not reach statistical significance at 12 months. In addition, the peak hip extension angle during walking increased 12 months after PAO, though not statistically significantly. There were no statistically significant differences in peak hip extension angle and peak hip flexion moment between the patients and the healthy controls after 12 months.Interpretation — Walking and running characteristics improved after PAO in patients with symptomatic hip dysplasia, although gait modifications were still present 12 months postoperatively.

Changes in walking and running in patients with hip dysplasia

Background and purpose Earlier studies have suggested that the hip extension angle and the hip flexor moment in walking are affected by hip dysplasia, but to our knowledge there have been no reports on running or evaluations of self-reported health. We evaluated differences in walking, running, and self-reported health between young adults with symptomatic hip dysplasia and healthy controls.Patients and methods Walking and running in 32 patients with hip dysplasia, mean 34 (18–53) years old, was compared with walking and running in 32 controls, mean 33 (18–54) years old. Joint kinematics and kinetics—quantified by the peak hip extension angle and the peak net joint moment of hip flexion during walking and running—were recorded using a motion-capture system, and health was evaluated using the Copenhagen Hip and Groin Outcome Score (HAGOS).Results The peak hip extension angle during walking was less in the patients than in the controls (–10.4 (SD 4.8) degrees vs. –13.2 (SD 4.5) degrees; p = 0.02). Similarly, the peak net joint moment of hip flexion during walking was lower in the patients than in the controls (0.57 (SD 0.13) N*m/kg vs. 0.70 (SD 0.22) N*m/kg; p = 0.008). In all dimensions of HAGOS, the patients scored lower than the controls. Furthermore, the hip extension angle and the net joint moment of hip flexion correlated with the HAGOS subscales pain and physical function in sport and recreation.Interpretation Patients with symptomatic hip dysplasia do modify walking and running, and we therefore suggest that the impairment found in this study should play an important role in the evaluation of later operative and training interventions.

Does Surgical Approach During Total Hip Arthroplasty Alter Gait Recovery During the First Year Following Surgery?

Multiple surgical approaches exist for total hip arthroplasty (THA). Each approach has risks and benefits in regard to complications and changes in postoperative gait. This study examined the effect of three surgical approaches on postoperative gait mechanics. Thirty patients completed a self-selected speed level walking gait assessment preoperatively, 6 weeks, and 1 year after surgery. We found no difference between approaches 1 year following surgery for any study variable. Several differences existed between time points independent of surgical approach. Significant improvement was found in sagittal and frontal plane hip ROM, peak hip extension and adduction angle and moment, the functional measures, walking speed, and the Harris Hip Score. This study suggests that postoperative gait changes are similar for the three analyzed surgical approaches.