Kinematic and kinetic differences during walking in patients with and without symptomatic femoroacetabular impingement

BackgroundFemoroacetabular impingement is a common hip pathology resulting in pain and impaired physical function. However, very little is known about gait differences between those with and without femoroacetabular impingement. Thus, the purpose of this study was to compare three-dimensional gait kinematics and kinetics between those with femoroacetabular impingement and a healthy, pain-free control group.MethodsThree-dimensional gait analysis was conducted on 30 individuals with symptomatic femoroacetabular impingement scheduled for surgery and 30 pain-free controls. Spatiotemporal and peak hip kinematics and joint moments were compared between the two groups. Ensemble averages were also calculated for kinematic and kinetic profiles across the gait cycle in all three planes of movement for visual inspection.FindingsParticipants with femoroacetabular impingement walked slower and with significantly smaller cadences than those in the control group. Kinematically, the impingement group exhibited significantly less peak hip extension, adduction and internal rotation during stance, with effect sizes ranging from 0.48 (adduction) to 1.00 (internal rotation). Finally, those with FAI exhibited significantly less peak external hip flexion (effect size = 0.52) and external rotation (effect size = 0.85) moments than the control group.InterpretationIndividuals with femoroacetabular impingement exhibit differences in gait kinematics in all planes of motion compared to those with without FAI. These findings support the need for focused neuromuscular reconditioning across all movement directions in this patient group.     

Vacuum level effects on gait characteristics for unilateral transtibial amputees with elevated vacuum suspension

BackgroundThe elevated vacuum suspension system has demonstrated unique health benefits for amputees, but the effect of vacuum pressure values on gait characteristics is still unclear. The purpose of this study was to investigate the effects of elevated vacuum levels on temporal parameters, kinematics and kinetics for unilateral transtibial amputees.MethodsThree-dimensional gait analysis was conducted in 9 unilateral transtibial amputees walking at a controlled speed with five vacuum levels ranging from 0 to 20 in Hg, and also in 9 able-bodied subjects walking at self-preferred speed. Repeated ANOVA and Dunnett's t-test were performed to determine the effect of vacuum level and limb for within subject and between groups.FindingsThe effect of vacuum level significantly affected peak hip external rotation and external knee adduction moment. Maximum braking and propulsive ground reaction forces generally increased for the residual limb and decreased for the intact limb with increasing vacuum. Additionally, the intact limb experienced an increased loading due to gait asymmetry for several variables.InterpretationThere was no systematic vacuum level effect on gait. Higher vacuum levels, such as 15 and 20 in Hg, were more comfortable and provided some relief to the intact limb, but may also increase the risk of osteoarthritis of the residual limb due to the increased peak external hip and knee adduction moments. Very low vacuum should be avoided because of the negative effects on gait symmetry. A moderate vacuum level at 15 in Hg is suggested for unilateral transtibial amputees with elevated vacuum suspension.     

Effects of hip and trunk muscle strengthening on hip function and lower limb kinematics during step-down task

BackgroundStrengthening of the hip and trunk muscles has the potential to change lower limb kinematic patterns, such as excessive hip medial rotation and adduction during weight-bearing tasks. This study aimed to investigate the effect of hip and trunk muscles strengthening on hip muscle performance, hip passive properties, and lower limb kinematics during step-down task in women.MethodsThirty-four young women who demonstrated dynamic knee valgus during step-down were divided into two groups. The experimental group underwent three weekly sessions of strengthening exercises for eight weeks, and the control group continued their usual activities. The following evaluations were carried out: (a) isokinetic maximum concentric and eccentric work of hip lateral rotators, (b) isokinetic hip passive torque of lateral rotation and resting transverse plane position, and (c) three-dimensional kinematics of the lower limb during step-down.FindingsThe strengthening program increased concentric (P < 0.001) and eccentric (P < 0.001) work of hip lateral rotators, and changed hip resting position toward lateral rotation (P < 0.001). The intervention did not significantly change hip passive torque (P = 0.089, main effect). The program reduced hip (P = 0.002), thigh (P = 0.024) and shank (P = 0.005) adduction during step-down task. Hip, thigh and knee kinematics in transverse plane and foot kinematics in frontal plane did not significantly modify after intervention (P ≥ 0.069, main effect).InterpretationHip and trunk strengthening reduced lower limb adduction during step-down. The changes in hip maximum work and resting position may have contributed to the observed kinematic effects.     

Age explains limited hip extension recovery at one year from total hip arthroplasty

BackgroundTo investigate the dependency of the one-year recovery in gait after total hip arthroplasty on age and preoperative conditions.MethodsLongitudinal retrospective study on 20 elderly patients with unilateral total hip arthroplasty consequent to hip osteoarthritis, assessed by gait analysis before surgery (T0), 2 weeks (T1), 6 (T2) and 12 months (T3) post-surgery. A set of variables assessing primary gait deviations and compensatory mechanisms were extracted from gait analysis data. Their variations throughout the one-year period were analyzed through a repeated measures ANOVA. Their dependency on preoperative conditions (age, hip passive limitations and Thomas Test) at one year after surgery were assessed through a correlation analysis and an ANCOVA.FindingsHip sagittal range significantly increased (P < 0.05) after each measurement session from mean 21 (SD 10) degrees at T0, to 31 (6) at T1, to 34 (6) at T2 until 36 (4) degrees at T3. The peak of hip and ankle power generation significantly increased from T0 to T3, with a progressive reduction of compensatory mechanisms towards normal values.At T3, preoperative hip passive extension and Thomas Test score did not affect hip sagittal range during gait, while age did (P < 0.05, R² = 0.36). Ankle and hip peak powers were also correlated with age (P = 0.033 and P = 0.008, respectively). In our sample, age was the main cause of hip sagittal joint range limitation.InterpretationAt one year from total hip arthroplasty, age affects hip joint limitations and gait recovery more than preoperative passive restrictions due to muscle shortening.     

The role of knee joint moments and knee impairments on self-reported knee pain during gait in patients with knee osteoarthritis

BackgroundThe association between high mechanical knee joint loading during gait with onset and progression of knee osteoarthritis has been extensively studied. However, less attention has been given to risk factors related to increased pain during gait. The purpose of this study was to evaluate knee joint moments and clinical characteristics that may be associated with gait-related knee pain in patients with knee osteoarthritis.MethodsSixty-seven participants with knee osteoarthritis were stratified into three groups of no pain (n = 18), mild pain (n = 27), or moderate/severe pain (n = 22) based on their self-reported symptoms during gait. All participants underwent three-dimensional gait analysis. Quadriceps strength, knee extension range of motion, radiographic knee alignment and self-reported measures of global pain and function were also quantified.FindingsThe moderate/severe pain group demonstrated worse global pain (P < 0.01) and physical function scores (P < 0.01) compared to the no pain and the mild pain groups. The moderate/severe pain group also walked with greater knee flexion moments during the midstance phase of gait compared to the no pain group (P = 0.02). Additionally, the moderate/severe pain group demonstrated greater varus knee malalignment (P = 0.009), which was associated with higher weight acceptance peak knee adduction moments (P = 0.003) and worse global pain (P = 0.003) and physical function scores (P = 0.006).InterpretationGreater knee flexion moment is present during the midstance phase of gait in patients with knee osteoarthritis and moderate/severe pain during gait. Additionally, greater varus malalignment may be a sign of increased global knee joint dysfunction that can influence many activities of daily living beyond gait.     

The immediate effects of foot orthoses on hip and knee kinematics and muscle activity during a functional step-up task in individuals with patellofemoral pain

BackgroundEvidence shows that anti-pronating foot orthoses improve patellofemoral pain, but there is a paucity of evidence concerning mechanisms. We investigated the immediate effects of prefabricated foot orthoses on (i) hip and knee kinematics; (ii) electromyography variables of vastus medialis oblique, vastus lateralis and gluteus medius during a functional step-up task, and (iii) associated clinical measures.MethodsHip muscle activity and kinematics were measured during a step-up task with and without an anti-pronating foot orthoses, in people (n = 20, 9 M, 11 F) with patellofemoral pain. Additionally, we measured knee function, foot posture index, isometric hip abductor and knee extensor strength and weight-bearing ankle dorsiflexion.FindingsReduced hip adduction (0.82°, P = 0.01), knee internal rotation (0.46°, P = 0.03), and decreased gluteus medius peak amplitude (0.9 mV, P = 0.043) were observed after ground contact in the ‘with orthoses’ condition. With the addition of orthoses, a more pronated foot posture correlated with earlier vastus medialis oblique onset (r = − 0.51, P = 0.02) whilst higher Kujala scores correlated with earlier gluteus medius onset (r = 0.52, P = 0.02).InterpretationAlthough small in magnitude, reductions in hip adduction, knee internal rotation and gluteus medius amplitude observed immediately following orthoses application during a task that commonly aggravates symptoms, offer a potential mechanism for their effectiveness in patellofemoral pain management. Given the potential for cumulative effects of weight bearing repetitions completed with a foot orthoses, for example during repeated stair ascent, the differences are likely to be clinically meaningful.     

Hip kinematics and kinetics in persons with and without cam femoroacetabular impingement during a deep squat task

BackgroundPrevious studies have indicated that hip and pelvis kinematics may be altered during functional tasks in persons with femoroacetabular impingement. The purpose of this study was to compare hip and pelvis kinematics and kinetics during a deep squat task between persons with cam femoroacetabular impingement and pain-free controls.MethodsFifteen persons with cam femoroacetabular impingement and 15 persons without cam femoroacetabular impingement performed a deep squat task. Peak hip flexion, abduction, and internal rotation, and mean hip extensor, adductor, and external rotator moments were quantified. Independent t-tests (α < 0.05) were used to evaluate between group differences.FindingsCompared to the control group, persons with cam femoroacetabular impingement demonstrated decreased peak hip internal rotation (15.2° (SD 9.5°) vs. 9.4° (SD 7.8°); P = 0.041) and decreased mean hip extensor moments (0.56 (SD 0.12) Nm/kg vs. 0.45 (SD 0.15) Nm/kg; P = 0.018). In addition persons in the cam femoroacetabular impingement group demonstrated decreased posterior pelvis tilt during squat descent compared to the control group, resulting in a more anteriorly tilted pelvis at the time peak hip flexion (12.5° (SD 17.1°) vs. 23.0° (SD 12.4°); P = 0.024).InterpretationThe decreased hip internal rotation observed in persons with cam femoroacetabular impingement may be the result of bony impingement. Furthermore, the decrease in posterior pelvis tilt may contribute to impingement by further approximating the femoral head–neck junction with the acetabulum. Additionally, decreased hip extensor moments suggest that diminished hip extensor muscle activity may contribute to decreased posterior pelvis tilt.     

Kinematic and kinetic gait deviations in males long after anterior cruciate ligament reconstruction

BackgroundBiomechanical deviations long (approx. 5 years) after anterior cruciate ligament reconstruction have not been quantified in males, despite their distinct risk profile as compared to females. These deviations can indicate altered joint loading during chronic, repetitive motions.MethodsCross-sectional study, comparing kinematic and kinetic variables between 15 male anterior cruciate ligament reconstructed patients and 15 healthy controls. During walking and running gait, measurements were taken of impact dynamics, knee and hip sagittal plane angles and moments, and knee varus angles and adduction moments.FindingsComparing affected limbs to control limbs, significantly lower maximum (P = 0.001) and initial (P = 0.003) loading rates were found during running, but not in walking. Hip angles were lower for affected limbs of patients compared to the control group (P = 0.039) in walking, but not during running. Between-limb comparisons showed important differences in symmetry of the affected patients. Maximum force during running was higher in the unaffected limb (P = 0.015), which was linked with a higher loading rate (P = 0.008). Knee flexion angle was reduced by 2° on average for the affected limb during running (P = 0.010), and both walking and running knee and hip moments showed differences. Knee varus angle showed a 1° difference during walking (P < 0.001), but not during running. Knee adduction moment was significantly lower (more valgus) during both walking and running.InterpretationMale anterior cruciate ligament reconstructed patients demonstrate persistent, clinically important gait asymmetries and differences from healthy controls long after surgery in kinematics, kinetics, and impact biomechanics.     

Reliability and validity of the Four Square Step Test in patients with hip osteoarthritis before and after total hip replacement

ObjectiveTo determine the validity and inter- and intra-rater reliability of the Four Square Step Test (FSST) in assessing gait performance, balance and physical function for patients with hip osteoarthritis before and after total hip replacement (THR).DesignObservational, repeated measures.SettingA specialist orthopaedic hospital.ParticipantsFifty-eight participants with moderate to severe hip osteoarthritis scheduled to receive primary hip replacement within 4 months from recruitment.Main outcome measureTime to complete the FSST, time and steps to complete the Figure of 8 Walk Test (F8W) and Berg Balance Scale score (BBS).ResultsThe Bland and Altman limits of agreement for intra-rater measurements of the FSST were −3.2 s to 3.5 seconds before THR and −1.5 to 2.0 seconds after THR. Limits of agreement for two different raters were −2.2 to 3.4 seconds, all with small mean differences indicating little bias between raters or replications. Concurrent validity was assessed, and the FSST correlated highly with the F8W (r = 0.7, P < 0.001) and moderately with the BBS (r = 0.6, P < 0.001). Only one participant was rated as being at moderate risk of falls on the BBS, with the other participants scoring low; only one participant failed to complete the F8W. This is in contrast to the FSST, which 21 people failed to complete pre-operatively.ConclusionsThe FSST is a valid and reliable measure of multi-directional stepping speed and balance, giving a more informative measure of gait performance than the F8W and BBS, and is feasible for use in a clinical population of patients both before and after THR.     

A multiple regression normalization approach to evaluation of gait in total knee arthroplasty patients

BackgroundGait features characteristic of a cohort may be difficult to evaluate due to differences in subjects' demographic factors and walking speed. The aim of this study was to employ a multiple regression normalization method that accounts for subject age, height, body mass, gender, and self-selected walking speed in the evaluation of gait in unilateral total knee arthroplasty patients.MethodsThree-dimensional gait analysis was performed on 45 total knee arthroplasty patients and 31 aged-matched controls walking at their self-selected speed. Gait data peaks including joint angles, ground reaction forces, net joint moments, and net joint powers were normalized using subject body mass, standard dimensionless equations, and a multiple regression approach that modeled subject age, height, body mass, gender, and self-selected walking speed.FindingsNormalizing gait data using subject body mass, dimensionless equations, and multiple regression approach resulted in a significantly lower knee adduction moment and knee extensor power in total knee arthroplasty patients compared to controls (p < 0.05). In contrast to normalization using body mass and dimensionless equations, multiple regression normalization greatly reduced variance in gait data by minimizing correlations with subject demographic factors and walking speed, resulting in significantly higher peak hip extension angles and peak hip flexion powers in total knee arthroplasty patients (p < 0.05).InterpretationTotal knee arthroplasty patients generate greater hip extension angles and hip flexor power and have a lower knee adduction moment than healthy controls. This gait pattern may be a strategy to reduce muscle and joint loading at the knee.     

Sex specific associations between biomechanical recovery and clinical recovery after total hip arthroplasty

BackgroundThere are sex-specific gait differences in men and women before and after total hip arthroplasty (THA) but we do not know their impact on clinical outcomes. The objective of this study was to identify sex-specific associations between pre- and postoperative changes in pain and function and (i) gait mechanics, (ii) passive range of motion, and (iii) abductor strength.MethodsPre- and one-year postoperative data were identified from a data repository (n = 124; 64 Women; Age 61 (SD 10); BMI 29 (SD 5)). We used linear regression analysis to identify sex-specific associations between Harris Hip Score pain and function subscores, and sagittal plane hip kinematics and 3D hip kinetics during gait, hip abductor strength, and passive hip range of motion (RoM).FindingsCombinations of biomechanical variables predicted up to 24% of the variation in pain improvement and up to 27% of the variation in functional improvement. In men, increased peak external rotation moments were associated with pain improvement. Passive flexion RoM and peak extension moments were associated with functional improvement. In women, increased passive adduction RoM and peak external rotation moments were associated with pain improvement. Peak adduction moments and passive flexion RoM were associated with functional improvement.InterpretationsThe different associations between improvement in clinical outcomes and improvement in gait, passive RoM, and abductor strength suggest that the biomechanical path to recovery may be different in men and women.     

The influence of sex and obesity on gait biomechanics in people with severe knee osteoarthritis scheduled for arthroplasty

BackgroundSex and body mass may influence knee biomechanics associated with poor total knee arthroplasty (TKA) outcomes for knee osteoarthritis (OA). This study aimed to determine if gait differed between men and women, and overweight and class I obese patients with severe knee OA awaiting TKA.Methods34 patients with severe knee OA (average age 70.0 (SD 7.2) years, body mass index 30.3 (4.1 kg/m²)) were recruited from a TKA waiting list. Three-dimensional gait analysis was performed at self-selected walking speed. Comparisons were made between men and women, and overweight (body mass index (BMI) 25.0–29.9 kg/m²) and class I obese (BMI 30.0–34.9 kg/m²) participants. Biomechanical outcomes included absolute and body size-adjusted peak knee adduction moment (KAM), KAM impulse, peak knee flexion moment, as well as peak knee flexion and varus-valgus angles, peak varus-valgus thrust, and peak vertical ground reaction force (GRF).FindingsMen had a higher absolute peak KAM, KAM impulse and peak GRF compared to women, and this sex-difference in frontal plane moments remained after adjusting for body size. However, when additionally adjusting for static knee alignment, differences disappeared. Knee biomechanics were similar between obesity groups after adjusting for the greater body weight of those with class I obesity.InterpretationMen had greater KAM and KAM impulse even after adjustment for body size; however adjustment for their more varus knees removed this difference. Obesity group did not influence knee joint kinematics or moments. This suggests sex- and obesity-differences in these variables may not be associated with TKA outcomes.     

Neuromechanical gait adaptations in women with joint hypermobility — An exploratory study

BackgroundJoint hypermobility is known to be associated with joint and muscle pain, joint instability and osteoarthritis. Previous work suggested that those individuals present an altered neuromuscular behavior during activities such as level walking. Therefore, the aim of this study was to explore the differences in ground reaction forces, temporal parameters and muscle activation patterns during gait between normomobile and hypermobile women, including symptomatic and asymptomatic hypermobile individuals.MethodsA total of 195 women were included in this cross-sectional study, including 67 normomobile (mean 24.8 [SD 5.4] years) and 128 hypermobile (mean 25.8 [SD 5.4] years), of which 56 were further classified as symptomatic and 47 as asymptomatic. The remaining 25 subjects could not be further classified. Ground reaction forces and muscle activation from six leg muscles were measured while the subjects walked at a self-selected speed on an instrumented walkway. Temporal parameters were derived from ground reaction forces and a foot accelerometer. The normomobile and hypermobile groups were compared using independent samples t-tests, whereas the normomobile, symptomatic and asymptomatic hypermobile groups were compared using one-way ANOVAs with Tukey post-hoc tests (significance level = 0.05).FindingsSwing phase duration was higher among hypermobile (P = 0.005) and symptomatic hypermobile (P = 0.018) compared to normomobile women. The vastus medialis (P = 0.049) and lateralis (P = 0.030) and medial gastrocnemius (P = 0.011) muscles showed higher mean activation levels during stance in the hypermobile compared to the normomobile group.InterpretationHypermobile women might alter their gait pattern in order to stabilize their knee joint.     

Sex differences in trunk,pelvis, hip and knee kinematics and eccentric hip torque in adolescents

BackgroundAdolescents have a high incidence of knee joint dysfunctions, with up to 28% of adolescents reporting knee pain. Although adolescent females have a greater incidence of knee injuries in comparison to males, few studies conducted biomechanical evaluations in this population aiming to identify sex differences. If trunk and/or lower limb biomechanical impairments are identified in female adolescents, the implementation of early interventions for injury prevention will be better justified. The purpose of this study was to compare the trunk, pelvis, hip and knee kinematics during a single-leg squat task, as well as the isokinetic eccentric hip torque, between male and female healthy adolescents.MethodsForty-four healthy adolescents were divided into two groups, group of males (n = 22) and group of females (n = 22). Kinematics during single-leg squat were assessed using a electromagnetic tracking system. For the evaluation of eccentric hip torque in the three planes an isokinetic dynamometer was used. Group differences were assessed using a one-way multivariate analysis of variance.FindingsResults showed that adolescent females presented greater hip adduction, hip external rotation and knee abduction, as well as smaller trunk flexion during single-leg squat in comparison to males. Additionally, adolescent females showed smaller isokinetic eccentric hip torque normalized by body mass in all planes in comparison to males.InterpretationThese sex differences in terms of trunk/lower limb kinematics and eccentric hip torque generation might play an important role in the greater incidence of overuse knee injuries observed in adolescent females.     

Changes in gait characteristics of women with early and established medial knee osteoarthritis: Results from a 2-years longitudinal study

BackgroundDespite the large number of cross-sectional studies on gait in subjects with knee osteoarthritis, there are scarcely any longitudinal studies on gait changes in knee osteoarthritis.MethodsGait analysis was performed on 25 women with early and 18 with established medial knee osteoarthritis, as well as a group of 23 healthy controls. Subjects were asked to walk at their comfortable speed. Kinematic and kinetic data were measured at baseline and after 2 years follow-up.FindingsResults indicated that the early osteoarthritis group, similar to established osteoarthritis group, showed significantly higher maximum knee adduction angles compared to the controls during the early stance phase of gait. None of the kinematic or kinetic measures, changed over two years in the early osteoarthritis group. In the established osteoarthritis group, at the time of entry, an increased first and second peak knee adduction moment, as well as higher mid-stance knee adduction moment and knee adduction moment impulse, were present compared to the control and the early osteoarthritis groups. Mid-stance knee adduction moment and knee adduction moment impulse, further increased over two years only in the established osteoarthritis group. For all three groups, the peak knee flexion angle during the stance phase decreased significantly over time.InterpretationIncreased maximum knee adduction angle during stance phase was the only alteration in the gait pattern of subjects with early knee osteoarthritis compared to the controls. This suggests that, unlike in the later stages of the disease, gait is rather stable over two years in early osteoarthritis.     

Trunk and lower limb biomechanics during stair climbing in people with and without symptomatic femoroacetabular impingement

BackgroundFemoroacetabular impingement is a pathomechanical hip condition leading to pain and impaired physical function. It has been shown that those with femoroacetabular impingement exhibit altered gait characteristics during level walking and stair climbing, and decreased muscle force production during isometric muscle contractions. However, no studies to-date have looked at trunk kinematics or muscle activation during dynamic movements such as stair climbing in this patient population. The purpose of this study was to compare biomechanical outcomes (trunk and lower limb kinematics as well as lower limb kinetics and muscle activation) during stair climbing in those with and without symptomatic femoroacetabular impingement.MethodsTrunk, hip, knee and ankle kinematics, as well as hip, knee and ankle kinetics and muscle activity of nine lower limb muscles were collected during stair climbing for 20 people with clinical and radiographic femoroacetabular impingement and compared to 20 age- and sex-matched pain-free individuals.FindingsThose with femoroacetabular impingement ascended the stairs slower (effect size = 0.82), had significantly increased peak trunk forward flexion angles (effect size = 0.99) and external hip flexion moments (effect size = 0.94) and had decreased peak external knee flexion moments (effect size = 0.90) compared to the control group.InterpretationFindings from this study indicate that while those with and without femoroacetabular impingement exhibit many biomechanical similarities when ascending stairs, differences in trunk forward flexion and joint kinetics indicate some important differences. Further longitudinal research is required to elucidate the cause of these differences as well as the clinical relevance.     

In vivo hip joint loads during three methods of walking with forearm crutches

BackgroundPatients with osteoarthritis, joint implants or fractures use crutches in order to reduce lower limb loading. However, insufficient information exists on how much the loading is then in fact reduced. This situation was studied by using seven patients who had instrumented hip implants.MethodsPart I: To investigate the effectiveness of forearm crutches, crutch and hip joint contact forces were measured in seven patients with instrumented hip prostheses. Additionally, the bending moments in the implant neck and torsion around its stem were determined. Reductions of peak loads during 3, 4, and 2-point gaits were compared with loads present when walking without crutches.Part II: This examines joint load reduction during a 4-point gait from one to 12 weeks post-operatively.FindingsPart I: During a 3, 4, and 2-point gait, the joint force was 17, 12, and 13% lower than it was while walking without crutches. The corresponding reductions of the bending moment were 16, 11, and 12%, while the maximum torque decreased by 19, 21, and 10%.Part II: The reductions of contact forces in comparison with walking without crutches were highest during the first 4 weeks after surgery. One and 4 weeks post-operatively, the force maximum was 21 and 8% lower than it was after 3 months. When compared with the initial values of the 1st week, crutch forces decreased by 28% in the 4th week and by 38% in the 3rd month.InterpretationAverage reductions of the joint load by more than 20% are achieved only during the first 4 post-operative weeks. Because fractures are in most cases relatively stable after 6 weeks, and bone ingrowth into implant interfaces is nearly finished after this time, a single crutch and a 2-point gait can be prescribed during the 5th and 6th post-operative week.     

Rehabilitation improves walking kinematics in children with a knee varus: Randomized controlled trial

Background

Previous studies have demonstrated increased medial stresses in knee varus alignment. Selecting a suitable treatment strategy for individuals with knee malalignment should be a priority.

Effects of hip joint transverse plane range of motion with a modeled effusion and capsular tear: A cadaveric study

BackgroundMultiple factors contribute to range of motion of the hip joint in the transverse plane: bony anatomy, hip capsule, corresponding ligaments, articular labrum, ligamentum teres, and negative intra-articular pressure. We hypothesized that violation of the negative pressure of the hip and simulation of an effusion would increase range of motion in the transverse plane in a cadaver model.MethodsTen hip specimens were obtained and dissected with the femur and iliac wing mounted in a custom joint-testing rig in neutral position. Specimens were tested at 0 and at 90° of flexion with 1.5 Nm internal and external rotational torque. Three conditions were assessed: (1) intact specimen, (2) an effusion modeled by a 10 ml saline infusion, and (3) a capsular tear.FindingsThe modeled effusion decreased rotational range of motion limits in both 0 and 90° of flexion, with a greater effect on the specimens at 0° flexion in external rotation with 4.1° less external rotation (p = 0.009). A modeled capsular tear increased rotational motion limits in 0° of flexion in both internal and external rotation and in 90° flexion in internal rotation only (p < 0.025).InterpretationAn effusion may decrease the rotation of the hip, and a capsular tear may increase its rotation. This should be considered in hips with traumatic capsular tears or arthroscopic portals.