Contralateral Pelvic Drop Research Articles

Gait biomechanics and hip muscular strength in patients with patellofemoral osteoarthritis

A significant number of patients with patellofemoral osteoarthritis (PFOA) have described a history of patellofemoral pain syndrome (PFPS). This leads to speculation that the underpinning mechanical causes of PFPS and PFOA may be similar. Although alterations in gait biomechanics and hip strength have been reported in PFPS, this relationship has not yet been explored in PFOA. Therefore the purpose of this study was compare gait biomechanics and hip muscular strength between PFOA patients and a healthy control group. Fifteen patients with symptomatic, radiographic PFOA and 15 controls participated. All patients underwent a walking gait analysis and maximal hip strength testing. Biomechanical variables of interest included the peak angular values of contra-lateral pelvic drop, hip adduction and hip internal rotation during the stance phase. Hip abduction and external rotation strength were assessed using maximal voluntary isometric contractions. The PFOA group demonstrated significantly lower hip abduction strength compared to controls but no difference in hip external rotation strength. There were no statistical differences between the PFOA and control groups for contra-lateral pelvic drop, hip adduction and hip internal rotation angles during walking. Despite patients with PFOA exhibiting weaker hip abductor muscle strength compared to their healthy counterparts they did not demonstrate alterations in pelvis or hip biomechanics during gait. These preliminary data suggests that weaker hip abductor strength does not result in biomechanical alterations during gait in this population.

The effect of contralateral pelvic drop and trunk lean on frontal plane knee biomechanics during single limb standing

Pelvic drop as a result of hip abductor weakness has been hypothesized as a potential modifier of frontal plane knee joint kinetics during gait in individuals with pathology such as knee osteoarthritis (OA). However, hip muscle strengthening interventions have failed to find significant reductions in frontal plane loading measures such as the external knee adduction moment (KAM) with altered hip strength. Since this could in part be due to a lack of change in pelvic kinematics between conditions or test sessions or due to alterations in lateral trunk lean angle, the relationship between pelvic drop and subsequent changes in centre of mass with knee joint loading remains unclear. The purpose of this study was to examine the effect of a consciously altered frontal plane centre of mass position (pelvic drop and trunk lean to the contralateral side) on the KAM during single limb standing. Twenty healthy individuals performed a series of single limb standing trials, where they were asked to balance on their dominant leg. KAM was assessed during single limb stance in two conditions: with pelvis and trunk maintained in a level position, and with contralateral pelvic drop. A third condition involving contralateral pelvic drop and trunk lean was assessed to examine exaggerated changes in centre of mass. The KAM increased significantly with contralateral pelvic drop (p=0.001) and with combined contralateral pelvic drop and trunk lean (p<0.001) compared to the level pelvis trials. These findings suggest that pelvic drop alone can significantly increase KAM magnitude, a risk factor for the progression of knee OA. Assessment of pelvic obliquity prior to treatment may allow those with marked pelvic drop to be targeted for hip muscle strengthening.

Frontal Plane Biomechanics in Males and Females with and without Patellofemoral Pain

The study's purpose was to compare trunk, pelvis, hip, and knee frontal plane biomechanics in males and females with and without patellofemoral pain syndrome (PFPS) during stepping. Eighty recreational athletes were equally divided into four groups: female PFPS, female controls, male PFPS, and male controls. Trunk, pelvis, hip, and knee frontal plane kinematics and activation of the gluteus medius were evaluated at 15°, 30°, 45°, and 60° of knee flexion during the downward and upward phases of the stepping task. Isometric hip abductor torque was also evaluated. Females showed increased hip adduction and knee abduction at all knee flexion angles, greater ipsilateral trunk lean and contralateral pelvic drop from 60° of knee flexion till the end of the stepping task (P = 0.027-0.001), diminished hip abductor torque (P < 0.001), and increased gluteus medius activation than males (P = 0.008-0.001). PFPS subjects presented increased knee abduction at all the angles evaluated; greater trunk, pelvis, and hip motion from 45° of knee flexion of the downward phase till the end of the maneuver; and diminished gluteus medius activation at 60° of knee flexion, compared with controls (P = 0.034-0.001). Females with PFPS showed lower hip abductor torque compared with the other groups. Females presented with altered frontal plane biomechanics that may predispose them to knee injury. PFPS subjects showed frontal plane biomechanics that could increase the lateral patellofemoral joint stress at all the angles evaluated and could increase even more from 45° of knee flexion in the downward phase until the end of the maneuver. Hip abductor strengthening and motor control training should be considered when treating females with PFPS.

Mirror gait retraining for the treatment of patellofemoral pain in female runners

BackgroundAbnormal hip mechanics are often implicated in female runners with patellofemoral pain. We sought to evaluate a simple gait retraining technique, using a full-length mirror, in female runners with patellofemoral pain and abnormal hip mechanics. Transfer of the new motor skill to the untrained tasks of single leg squat and step descent was also evaluated. MethodsTen female runners with patellofemoral pain completed 8 sessions of mirror and verbal feedback on their lower extremity alignment during treadmill running. During the last 4 sessions, mirror and verbal feedback were progressively removed. Hip mechanics were assessed during running gait, a single leg squat and a step descent, both pre- and post-retraining. Subjects returned to their normal running routines and analyses were repeated at 1-month and 3-month post-retraining. Data were analyzed via repeated measures analysis of variance. FindingsSubjects reduced peaks of hip adduction, contralateral pelvic drop, and hip abduction moment during running (P<0.05, effect size=0.69–2.91). Skill transfer to single leg squatting and step descent was noted (P<0.05, effect size=0.91–1.35). At 1 and 3months post retraining, most mechanics were maintained in the absence of continued feedback. Subjects reported improvements in pain and function (P<0.05, effect size=3.81–7.61) and maintained through 3months post retraining. InterpretationMirror gait retraining was effective in improving mechanics and measures of pain and function. Skill transfer to the untrained tasks of squatting and step descent indicated that a higher level of motor learning had occurred. Extended follow-up is needed to determine the long term efficacy of this treatment.

Trunk, Pelvis, Hip, and Knee Kinematics, Hip Strength, and Gluteal Muscle Activation During a Single-Leg Squat in Males and Females With and Without Patellofemoral Pain Syndrome

Controlled laboratory study using a cross-sectional design. To determine whether there are any differences between the sexes in trunk, pelvis, hip, and knee kinematics, hip strength, and gluteal muscle activation during the performance of a single-leg squat in individuals with patellofemoral pain syndrome (PFPS) and control participants. Though there is a greater incidence of PFPS in females, PFPS is also quite common in males. Trunk kinematics may affect hip and knee function; however, there is a lack of studies of the influence of the trunk in individuals with PFPS. Eighty subjects were distributed into 4 groups: females with PFPS, female controls, males with PFPS, and male controls. Trunk, pelvis, hip, and knee kinematics and gluteal muscle activation were evaluated during a single-leg squat. Hip abduction and external rotation eccentric strength was measured on an isokinetic dynamometer. Group differences were assessed using a 2-way multivariate analysis of variance (sex by PFPS status). Compared to controls, subjects with PFPS had greater ipsilateral trunk lean (mean ± SD, 9.3° ± 5.3° versus 6.7° ± 3.0°; P = .012), contralateral pelvic drop (10.3° ± 4.7° versus 7.4° ± 3.8°; P = .003), hip adduction (14.8° ± 7.8° versus 10.8° ± 5.6°; P<.0001), and knee abduction (9.2° ± 5.0° versus 5.8° ± 3.4°; P<.0001) when performing a single-leg squat. Subjects with PFPS also had 18% less hip abduction and 17% less hip external rotation strength. Compared to female controls, females with PFPS had more hip internal rotation (P<.05) and less muscle activation of the gluteus medius (P = .017) during the single-leg squat. Despite many similarities in findings for males and females with PFPS, there may be specific sex differences that warrant consideration in future studies and when clinically evaluating and treating females with PFPS.

Proximal and distal kinematics in female runners with patellofemoral pain

BackgroundFemale runners have a high incidence of developing patellofemoral pain. Abnormal mechanics are thought to be an important contributing factor to patellofemoral pain. However, the contribution of abnormal trunk, hip, and foot mechanics to the development of patellofemoral pain within this cohort remains elusive. Therefore the aim of this study was to determine if significant differences during running exist in hip, trunk and foot kinematics between females with and without patellofemoral pain. Methods32 female runners (16 patellofemoral pain, 16 healthy control) participated in this study. All individuals underwent an instrumented gait analysis. Between-group comparisons were made for hip adduction, hip internal rotation, contra-lateral pelvic drop, contra-lateral trunk lean, rearfoot eversion, tibial internal rotation, as well as forefoot dorsiflexion and abduction FindingsThe patellofemoral pain group had significantly greater peak hip adduction and hip internal rotation. No differences in contra-lateral pelvic drop were found. A trend towards reduced contra-lateral trunk lean was found in the patellofemoral pain group. No significant differences were found in any of the rearfoot or forefoot variables but significantly greater shank internal rotation was found in the patellofemoral pain group. InterpretationWe found greater hip adduction, hip internal rotation and shank internal rotation in female runners with patellofemoral pain. We also found less contra-lateral trunk lean in the patellofemoral pain group. This may be a potential compensatory mechanism for the poor hip control seen. Rehabilitation programs that correct abnormal hip and shank kinematics are warranted in this population.

The Effect of a Hip-Strengthening Program on Mechanics During Running and During a Single-Leg Squat

Block randomized controlled trial. To investigate whether a strengthening and movement education program, targeting the hip abductors and hip external rotators, alters hip mechanics during running and during a single-leg squat. Abnormal movement patterns during running and single-leg squatting have been associated with a number of running-related injuries in females. Therapeutic interventions for these aberrant movement patterns typically include hip strengthening. While these strengthening programs have been shown to improve symptoms, it is unknown if the underlying mechanics during functional movements is altered. Twenty healthy females with excessive hip adduction during running, as determined by instrumented gait analysis, were recruited. The runners were matched by age and running distance, and randomized to either a training group or a control group. The training group completed a hip strengthening and movement education program 3 times per week for 6 weeks in addition to single-leg squat training with neuromuscular reeducation consisting of mirror and verbal feedback on proper mechanics. The control group did not receive an intervention but maintained the current running distance. Using a handheld dynamometer and standard motion capture procedures, hip strength and running and single-leg squat mechanics were compared before and after the strengthening and movement education program. While hip abductor and external rotation strength increased significantly (P<.005) in the training group, there were no significant changes in hip or knee mechanics during running. However, during the single-leg squat, hip adduction, hip internal rotation, and contralateral pelvic drop all decreased significantly (P = .006, P = .006, and P = .02, respectively). The control group exhibited no changes in hip strength, nor in the single-leg squat or running mechanics at the conclusion of the 6-week study. A training program that included hip strengthening and movement training specific to single-leg squatting did not alter running mechanics but did improve single-leg squat mechanics. These results suggest that hip strengthening and movement training, when not specific to running, do not alter abnormal running mechanics. Therapy, level 2b.

Comparison of 2D and 3D kinematic changes during a single leg step down following neuromuscular training

Objectives Evaluate the effects of a weight-bearing neuromuscular training program on 2D and 3D lower extremity kinematics during a single leg step down. Design Pre-test, post-test quasi experimental. Setting Laboratory. Participants Sixty nine healthy females performed a single leg step down. The 20 females with the most medial knee orientation during this task participated in this study (20.0 yr (1.6 yr), 167.9 cm (6.0 cm), 63.2 kg (8.3 kg)). Main Outcome Measures 2D knee frontal plane projection angle (FPPA) and 3D lower extremity joint (hip and knee) and segment (pelvis and femur) angles during a single leg step down before and after training were compared using paired t-tests. Pearson correlation coefficients were used to measure the association of 2D and 3D kinematic changes following training. Results Knee FPPA decreased 4.6° after training ( P < 0.001). Hip flexion ( P < 0.001) and hip adduction ( P = 0.04) increased after training. However, no other 3D joint kinematic changes were observed. Segment angle changes included decreased femoral internal rotation ( P = 0.008) and adduction ( P = 0.08) and increased anterior pelvic tilt ( P < 0.001) and contralateral pelvic drop ( P = 0.02). The association between changes in 2D and 3D joint kinematics ranged from 0.12 to 0.34. Conclusions Exercises intended to improve altered lower extremity kinematics may reduce medial knee 2D FPPA values during a single leg step down. However, this 2D change may not be linked with any specific change in 3D joint kinematics.

The Relationship Between Hip-Abductor Strength and the Magnitude of Pelvic Drop in Patients With Low Back Pain

It has been theorized that a positive Trendelenburg test (TT) indicates weakness of the stance hip-abductor (HABD) musculature, results in contralateral pelvic drop, and represents impaired load transfer, which may contribute to low back pain. Few studies have tested whether weakness of the HABDs is directly related to the magnitude of pelvic drop (MPD). To examine the relationship between HABD strength and MPD during the static TT and during walking for patients with nonspecific low back pain (NSLBP) and healthy controls (CON). A secondary purpose was to examine this relationship in NSLBP after a 3-wk HABD-strengthening program. Quasi-experimental. Clinical research laboratory. 20 (10 NSLBP and 10 CON). HABD strengthening. Normalized HABD strength, MPD during TT, and maximal pelvic frontal-plane excursion during walking. At baseline, the NSLBP subjects were significantly weaker (31%; P = .03) than CON. No differences in maximal pelvic frontal-plane excursion (P = .72), right MPD (P = 1.00), or left MPD (P = .40) were measured between groups. During the static TT, nonsignificant correlations were found between left HABD strength and right MPD for NSLBP (r = -.32, P = .36) and CON (r = -.24, P = .48) and between right HABD strength and left MPD for NSLBP (r = -.24, P = .50) and CON (r = -.41, P = .22). Nonsignificant correlations were found between HABD strength and maximal pelvic frontal-plane excursion for NSLBP (r = -.04, P = .90) and CON (r = -.14, P = .68). After strengthening, NSLBP demonstrated significant increases in HABD strength (12%; P = .02), 48% reduction in pain, and no differences in MPD during static TT and maximal pelvic frontal-plane excursion compared with baseline. HABD strength was poorly correlated to MPD during the static TT and during walking in CON and NSLBP. The results suggest that HABD strength may not be the only contributing factor in controlling pelvic stability, and the static TT has limited use as a measure of HABD function.

The effect of real-time gait retraining on hip kinematics, pain and function in subjects with patellofemoral pain syndrome

BackgroundPatellofemoral pain syndrome (PFPS) is the most common overuse injury in runners. Recent research suggests that hip mechanics play a role in the development of this syndrome. Currently, there are...

Individuals with severe knee osteoarthritis (OA) exhibit altered proximal walking mechanics compared with individuals with less severe OA and those without knee pain

To examine hip, pelvis, and trunk walking biomechanics in individuals with medial compartment knee osteoarthritis (OA) of varying radiographic disease severities and others without knee pain. Hip, pelvis, and trunk kinematics and hip kinetics were assessed in 75 individuals with radiographically confirmed OA and 20 asymptomatic individuals. Differences in peak hip adduction and abduction angles, the amount of contralateral pelvic drop, and peak lateral trunk lean measured by 3-dimensional gait analysis were examined using analyses of variance. Peak external hip abduction and adduction moments were compared using analyses of covariance, with gait speed as a covariate. Those with severe OA disease exhibited significantly less peak hip adduction (5.0°), but more ipsilateral trunk lean toward the study extremity (5.0°) than all other groups (P < 0.001). Those in the severe (1.1°) and asymptomatic (0.9°) groups also exhibited significantly less lateral trunk lean toward the non-study extremity (P = 0.004). No significant differences in hip joint moments or contralateral pelvic drop were observed between the groups (P > 0.02). Gait changes at the hip and trunk were evident across the groups based on radiographic disease severity and compared with those without knee pain. Although not conclusive from this cross-sectional study design, the results provide initial evidence to support increased lateral trunk lean as being a compensatory response to the disease.

Hip Strength and 3-D Mechanics During Running and Squatting in Asymptomatic Female Runners

Diminished hip strength in females with patellofemoral pain syndrome (PFPS) has been linked to excessive hip internal rotation (HIR), hip adduction (HADD) and contralateral pelvic drop (CPD). These relationships have also been found in healthy females, but only in the frontal plane. There have been no studies of correlations between hip strength with 3D kinematics in healthy females. This information may be helpful in identifying individuals who may be at risk for PFPS.FIGUREPURPOSE: To establish a relationship between hip strength and 3-D mechanics in asymptomatic individuals. It was hypothesized that hip abductor strength (HABDS) would correlate with HADD and CPD, and hip external rotator strength (HERS) would correlate with HIR during both running and a single leg squat (SLS). METHODS: 40 healthy female runners (22.7 yrs, 15.2 miles/wk) were recruited. Peak isometric HABDS and HERS were collected via a hand-held dynamometer. Kinematic data were then collected at 200 Hz while subjects performed 5 SLS's to 45° knee flexion, and while they ran on a treadmill at 3.35 m/s. Peak HADD, HIR, CPD were calculated. RESULTS: Unexpectedly, HABDS was not significantly correlated with either HADD or CPD during running or during the SLS. In addition, HERS was not significantly correlated with HIR during either activity. CONCLUSIONS: The lack of correlation between hip strength and hip kinematics may be due to the fact that this study examined healthy individuals in a fresh state. These correlations may be stronger once a threshold of weakness is met, which may be present in a more fatigued state. Additionally, timing of hip muscle firing may be more strongly correlated with hip kinematics than isometric strength. Support: NIH 1 S10 RR022396, DOD W911NF-05-1-0097

Lower Extremity Jumping Mechanics of Female Athletes with and without Patellofemoral Pain before and after Exertion

Background Patellofemoral pain is especially common among female athletes and is traditionally associated with lower extremity mechanics thought to increase retropatellar stress. These detrimental mechanics may increase with exertion. Hypothesis Differences in lower extremity mechanics during single-legged jumps between female athletes with and without patellofemoral pain will increase after exertion. Study Design Controlled laboratory study. Methods Twenty women with patellofemoral pain and 20 healthy female controls participated in a functional lower extremity exertion protocol of repetitive single-legged jumps. Pain, exertion, hip and trunk strength, and 3-dimensional lower extremity joint mechanics were recorded at the beginning and end of the protocol. Results The patellofemoral pain group reported increased pain at the conclusion of the protocol. However, all subjects terminated the protocol due to complaints of fatigue. Mean strength measurements for the patellofemoral pain group were 24% lower for lateral trunk flexion (P = .06), 13% lower for hip abduction (P = .09), and 14% lower for hip external rotation (P = .03) than for controls. Subjects with patellofemoral pain demonstrated greater contralateral pelvic drop at the end of the exertion protocol compared with the control group (P = .003). Group differences in lower extremity mechanics, including increased hip adduction angle, hip flexion angle, hip abduction angular impulse, and decreased hip internal rotation angles, were observed among women with patellofemoral pain throughout the exertion protocol. These group differences were consistent despite increased pain for the patellofemoral pain group after exertion. Both groups demonstrated decreased jump height, hip flexion and internal rotation, knee flexion, and hip extension impulse at the end of the protocol. Conclusion Women with patellofemoral pain demonstrated lower extremity mechanics that differed from the healthy control group during single-legged jumping, particularly at the hip. These differences do not appear to vary with exertion level or pain among patellofemoral pain subjects during single-legged jumps. Clinical Relevance Lower extremity jumping mechanics appear to be consistently different among women with patellofemoral pain. Conservative treatment programs that include kinematic retraining as well as hip and trunk strengthening may improve patient outcomes and prevent recurrence of this common orthopaedic condition.

Hip deformities in walking patients with cerebral palsy.

Hip deformities in walking patients with cerebral palsy are rare. Nineteen diplegic and four hemiplegic patients with unilateral hip subluxation were studied to determine whether or not characteristic gait patterns could be identified. All were examined clinically and radiologically as well as undergoing observational and instrumented three dimensional gait analysis. Twenty one of the patients compensated for the subluxation with an ipsilateral trunk lean and contralateral pelvic drop. These patterns were quantified in the kinematic and kinetic variables measured. We conclude that hip abductor weakness should be considered as the cause of the deformity.