Sex-specific hip osteoarthritis-associated gait abnormalities: Alterations in dynamic hip abductor function differ in men and women

BackgroundHip osteoarthritis results in abnormal gait mechanics, but it is not known whether abnormalities are the same in men and women. The hypothesis tested was that gait abnormalities are different in men and women with hip osteoarthritis vs. sex-specific asymptomatic groups.Methods150 subjects with mild through severe radiographic hip osteoarthritis and 159 asymptomatic subjects were identified from an Institutional Review Board-approved motion analysis data repository. Sagittal plane hip range of motion and peak external moments about the hip, in all three planes, averaged from normal speed walking trials, were compared for men and women, with and without hip osteoarthritis using analysis of variance.FindingsThere were significant sex by group interactions for the external peak hip adduction and external rotation moments (P = 0.009–0.045). Although asymptomatic women had peak adduction and external rotation moments that were respectively 12% higher and 23% lower than asymptomatic men (P = 0.026–0.037), these variables did not differ between men and women with hip osteoarthritis (P ≥ 0.684). The osteoarthritis vs. asymptomatic group difference in the peak hip adduction moment was 45% larger in women than in men. The osteoarthritis vs. asymptomatic group difference in the peak hip external rotation moment was 55% larger for men than for women (P < 0.001). Sex did not influence the association between radiographic severity and gait variables.InterpretationNormal sex differences in gait were not seen in hip osteoarthritis. Sex-specific adaptations may reflect different aspects of hip abductor function. Men and women with hip osteoarthritis may require different interventions to improve function.     

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.     

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.     

Improvements in kinematics,muscle activity and pain during functional tasks in females with patellofemoral pain following a single patterned electrical stimulation treatment

BackgroundIndividuals with patellofemoral pain present with altered hip muscle activation, faulty movement patterns, and pain during functional tasks. Examining new treatment options to address these impairments may better treat those with patellofemoral pain. The purpose of this study was to determine if patterned electrical stimulation to the lower extremity affects muscle activity, movement patterns, and pain following a single treatment.MethodsFifteen females with patellofemoral pain were randomized to receive a single 15-minute treatment of either a patterned electrical neuromuscular stimulation or a sham. Peak kinematics of the knee, hip, and trunk, electromyography and pain were examined pre and post-intervention during a single leg squat and lateral step-down task. Group means and pre/post reduced kinematic values were also plotted during the entire task with 90% confidence intervals to identify differences in movement strategies.FindingsNo baseline differences were found in peak kinematics between groups. No pre to post-intervention differences in peak knee, hip and trunk kinematics were found, however differences were seen when the quality of movement across the entire tasks was assessed. The electrical stimulation group had improved knee flexion and hip abduction during the lateral step-down. A significant improvement in gluteus medius activation following patterned electrical neuromuscular stimulation occurred during the step-down (P = 0.039). Significant pain improvements were also seen in both the single leg squat (P = 0.025) and lateral step-down (P = 0.006).InterpretationA single treatment of patterned electrical neuromuscular stimulation improved muscle activation, lower extremity kinematics during functional tasks, and pain.     

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.     

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.     

Re-evaluating the functional implications of the Q-angle and its relationship to in-vivo patellofemoral kinematics

BackgroundThe Q-angle is widely used clinically to evaluate individuals with anterior knee pain. Recent studies have questioned the utility of this measure and have suggested that a large Q-angle may not be associated with lateral patellofemoral translation, as often assumed. The objective of this study was to determine: 1) how accurately the Q-angle represents the line-of-action of the quadriceps and 2) if adding active quadriceps contraction or a bent knee position to the measurement of the Q-angle improves its reliability, accuracy, and association with patellofemoral kinematics.MethodsThe study included individuals diagnosed with chronic idiopathic patellofemoral pain and control subjects (n = 43 and n = 30 knees). Three measures of the clinical Q-angle (straight- and bent-knee with relaxed quadriceps and straight-knee with maximum isometric quadriceps contraction) were obtained with a goniometer and compared to a fourth MR-based measure of Q-angle. Patellofemoral kinematics were derived from dynamic cine-phase contrast images, acquired while subjects extended/flexed their knee from approximately 0° and 45°.FindingsThe Q-angle did not represent the line-of-action of the quadriceps. The average difference between each clinical and the MR-based Q-angle ranged from 5° to 8°. These differences varied greatly across subjects (range: − 28.5° to 3.9^o). Adding an active quadriceps contraction or a bent knee position, did not improve the reliability of the Q-angle. An increased Q-angle correlated to medial patellar displacement and tilt (r = 0.38—0.54, P < 0.001) in the cohort with anterior knee pain.InterpretationClinicians are cautioned against using the Q-angle to infer patellofemoral kinematics.     

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.     

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 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.     

The effect of a rotator cuff tear and its size on three-dimensional shoulder motion

BackgroundRotator cuff-disease is associated with changes in kinematics, but the effect of a rotator cuff-tear and its size on shoulder kinematics is still unknown in-vivo.MethodsIn this cross-sectional study, glenohumeral and scapulothoracic kinematics of the affected shoulder were evaluated using electromagnetic motion analysis in 109 patients with 1) subacromial pain syndrome (n = 34), 2) an isolated supraspinatus tear (n = 21), and 3) a massive rotator cuff tear involving the supraspinatus and infraspinatus (n = 54). Mixed models were applied for the comparisons of shoulder kinematics between the three groups during abduction and forward flexion.FindingsIn the massive rotator cuff-tear group, we found reduced glenohumeral elevation compared to the subacromial pain syndrome (16°, 95% CI [10.5, 21.2], p < 0.001) and the isolated supraspinatus tear group (10°, 95% CI [4.0, 16.7], p = 0.002) at 110° abduction. Reduced glenohumeral elevation in massive rotator cuff tears coincides with an increase in scapulothoracic lateral rotation compared to subacromial pain syndrome (11°, 95% CI [6.5, 15.2], p < 0.001) and supraspinatus tears (7°, 95% CI [1.8, 12.1], p = 0.012). Comparable differences were observed for forward flexion. No differences in glenohumeral elevation were found between the subacromial pain syndrome and isolated supraspinatus tear group during arm elevation.InterpretationThe massive posterosuperior rotator cuff-tear group had substantially less glenohumeral elevation and more scapulothoracic lateral rotation compared to the other groups. These observations suggest that the infraspinatus is essential to preserve glenohumeral elevation in the presence of a supraspinatus tear. Shoulder kinematics are associated with rotator cuff-tear size and may have diagnostic potential.     

Effects of thigh holster use on kinematics and kinetics of active duty police officers

BackgroundBody armour, duty belts and belt mounted holsters are standard equipment used by the Swedish police and have been shown to affect performance of police specific tasks, to decrease mobility and to potentially influence back pain. This study aimed to investigate the effects on gait kinematics and kinetics associated with use of an alternate load carriage system incorporating a thigh holster.MethodsKinematic, kinetic and temporospatial data were collected using three dimensional gait analysis. Walking tests were conducted with nineteen active duty police officers under three different load carriage conditions: a) body armour and duty belt, b) load bearing vest, body armour and thigh holster and c) no equipment (control).FindingsNo significant differences between testing conditions were found for temporospatial parameters. Range of trunk rotation was reduced for both load carriage conditions compared to the control condition (p < 0.017). Range of hip rotation was more similar to the control condition when wearing thigh holster rather than the belt mounted hip holster (p < 0.017). Moments and powers for both left and right ankles were significantly greater for both of the load carriage conditions compared to the control condition (p < 0.017).InterpretationThis study confirms that occupational loads carried by police have a significant effect on gait kinematics and kinetics. Although small differences were observed between the two load carriage conditions investigated in this study, results do not overwhelmingly support selection of one design over the other.     

Patients with osteoarthritic knees have shorter orientation and tangent indicatrices during gait

BackgroundThis study introduces two novel outcomes that could be used to identify people with knee osteoarthritis from healthy controls. These outcomes examine the lengths of paths on a sphere derived from knee angle and knee position during gait.MethodsParticipants with moderate knee osteoarthritis (n = 47) and no knee pathology (n = 51) walked overground. The time-varying orientation matrices and position vectors of the knee (leg relative to the thigh) were measured, then arclength (constant speed) parameterized. The orientation matrix column aligned with the long axis of the leg, and the tangent, normal and binormal vectors (Frenet Frame) along the position vectors were calculated. These unit length vectors all scribe paths (indicatrices) on a unit sphere. The path lengths of these indicatrices, for all or part of a gait cycle, were the novel outcomes. A stepwise discriminant analysis defined a linear function that included those outcomes that best allocated a participant to the osteoarthritis or control group.FindingsGroup differences were best detected with the indicatrix lengths associated with the orientation of the leg’s long axis over a gait cycle (P < 0.001) and the tangent vector over the stance phase (P = 0.014). Both outcomes were smaller in the knee osteoarthritis compared to control group. Walking speed was poorly correlated with all indicatrix lengths (ρ < |0.484|) and a discriminate analysis correctly classified 83.7% of the participants.InterpretationSmaller indicatrix measures distinguished those with knee osteoarthritis from healthy controls. These outcomes introduce a promising new kinematic approach when examining gait data.     

Differences in lumbar spine and lower extremity kinematics during a step down functional task in people with and people without low back pain

BackgroundWhen functional movements are impaired in people with low back pain, they may be a contributing factor to chronicity and recurrence. The purpose of the current study was to examine lumbar spine, pelvis, and lower extremity kinematics during a step down functional task between people with and without a history of low back pain.MethodsA 3-dimensional motion capture system was used to analyze kinematics during a step down task. Total excursion of the lumbar spine, pelvis, and lower extremity segments in each plane were calculated from the start to end of the task. Separate analysis of variance tests (α = 0.05) were conducted to determine the effect of independent variables of group and plane on lumbar spine, pelvis, and lower extremity kinematics. An exploratory analysis was conducted to examine kinematic differences among movement-based low back pain subgroups.FindingsSubjects with low back pain displayed less lumbar spine movement than controls across all three planes of movement (P-values = 0.001–0.043). This group difference was most pronounced in the sagittal plane. For the lower extremity, subjects with low back pain displayed more frontal and axial plane knee movement than controls (P-values = 0.001). There were no significant differences in kinematics among movement-based low back pain subgroups.InterpretationPeople with low back pain displayed less lumbar region movement in the sagittal plane and more off-plane knee movements than the control group during a step down task. Clinicians can use this information when assessing lumbar spine and lower extremity movement during functional tasks, with the goal of developing movement-based interventions.     

Kinematics and kinetics of single-limb heel rise in diabetes related medial column foot deformity

BackgroundDiabetes-related medial column foot deformities contribute to high plantar pressure, joint instability, ulceration and amputation. Impaired foot function may be an early indicator of foot structural incompetence and contribute to deformity progression. This study examines the ability of single-limb heel rise multi-segmental kinematics and kinetics to identify midfoot and hindfoot dysfunction in those with diabetes-related medial column foot deformity.MethodsSingle-limb heel rise foot kinematics and kinetics were examined in adults with diabetes mellitus and peripheral neuropathy with and without medial column foot deformity and age-, weight-matched controls.FindingsHindfoot relative to shank plantarflexion, peak and excursion, were reduced in both diabetes groups compared to controls (P < 0.017). Controls ' initial forefoot relative to hindfoot position was plantarflexed 31° and plantarflexed an additional 13° during heel rise. The initial forefoot relative to hindfoot position for the diabetes group without deformity was similarly plantarflexed as controls (34°) while the diabetes deformity group was less plantarflexed (lower arch position: 23°, P < 0.017). During the heel rise task both diabetes groups demonstrated less ability to plantarflex the forefoot relative to the hindfoot compared to controls (2 and 5° respectively, P < 0.017). Ankle plantarflexion power was reduced in the diabetes deformity group compared to controls (P < 0.017).InterpretationThe single-limb heel rise task identified movement dysfunction in those with diabetes mellitus and peripheral neuropathy. Failure to plantarflex the forefoot relative to hindfoot may compromise midfoot joint stability and increase the risk of injury and arch collapse.     

Scapular asymmetry in participants with and without shoulder impingement syndrome; a three-dimensional motion analysis

BackgroundThis study analyzed the dynamic three-dimensional scapular kinematics and scapular asymmetry in participants with and without shoulder impingement syndrome.MethodsTwenty-nine participants with shoulder impingement syndrome, have been suffering from unilateral shoulder pain at the dominant arm lasting more than six weeks and thirty-seven healthy controls participated in the study. Scapular kinematics was measured with an electromagnetic tracking device during shoulder elevation in the sagittal plane. Data for bilateral scapular orientation were analyzed at 30°, 60°, 90°, and 120° of humerothoracic elevation and lowering. The symmetry angle was calculated to quantify scapular asymmetry throughout shoulder elevation.FindingsStatistical comparisons indicated that the scapula was more downwardly rotated (p < 0.001) and anteriorly tilted (p = 0.005) in participants with shoulder impingement syndrome compared to healthy controls. Side-to-side comparisons revealed that the scapula was more anteriorly tilted on the involved side of participants with shoulder impingement syndrome (p = 0.01), and the scapula was rotated more internally (p = 0.02) and downwardly (p = 0.01) on the dominant side of healthy controls. Although there were side-to-side differences in both groups, symmetry angle calculation revealed that the scapular movement was more asymmetrical for scapular internal and upward rotation in individuals with shoulder impingement syndrome when compared with healthy controls (p < 0.05).InterpretationThe findings of the study increase our knowledge and understanding of scapular alterations in symptomatic and asymptomatic populations, which creates biomechanical considerations for shoulder assessment and rehabilitation.     

Correlations between ankle–foot impairments and dropped foot gait deviations among stroke survivors

BackgroundThe purpose of this paper is to 1) evaluate the relationship between ankle kinematics during gait and standardized measures of ankle impairments among sub-acute stroke survivors, and 2) compare the degree of stroke-related ankle impairment between individuals with and without dropped foot gait deviations.MethodsFifty-five independently ambulating stroke survivors participated in this study. Dropped foot was defined as decreased peak dorsiflexion during the swing phase and reduced ankle joint motion in stance. Standardized outcome measures included the Chedoke–McMaster Stroke Assessment (motor impairment), Modified Ashworth Scale (spasticity), Medical Research Council (muscle strength), passive and active range of motion, and isometric muscle force.FindingsFoot impairment was not related to peak dorsiflexion during swing (r = ? 0.17, P = 0.247) and joint motion during stance (r = 0.05, P = 0.735). Active (r = 0.45, P < 0.001) and passive (r = 0.48, P < 0.001) range of motion was associated with stance phase joint motion. Peak dorsiflexion during swing was related to isometric dorsiflexor muscle force (r = ? 0.32, P = 0.039). Individuals with dropped foot demonstrated greater motor impairment, plantarflexor spasticity and ankle muscle weakness compared to those without dropped foot.InterpretationOur investigation suggests that ankle–foot impairments are related to ankle deviations during gait, as indicated by greater impairment among individuals with dropped foot. These findings contribute to a better understanding of gait-specific ankle deviations, and may lead to the development of a more effective clinical assessment of dropped foot impairment.     

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.     

Recovery of balance and gait after stroke is deteriorated by confluent white matter hyperintensities: Cohort study

BackgroundWhite matter hyperintensities (WMHs) are well known to affect post-stroke disability, mainly by cognitive impairment. Their impact on post-stroke balance and gait disorders is unclear.ObjectivesWe aimed to test the hypothesis that WMHs would independently deteriorate post-stroke balance and gait recovery.MethodsThis study was performed in 210 individuals of the cohort Determinants of Balance Recovery After Stroke (DOBRAS), consecutively enrolled after a first-ever hemisphere stroke. Clinical data were systematically collected on day 30 ± 3 (D30) post-stroke and at discharge from the rehabilitation ward. WMHs were searched on MRI, graded with the Fazekas scale, and dichotomized as no/mild (absence/sparse) or moderate/severe (confluent). The primary endpoint was the recovery of the single limb stance, assessed with the Postural Assessment Scale for Stroke (PASS). The secondary endpoint was the recovery of independent gait, assessed with the modified Fugl–Meyer Gait Assessment (mFMA). The adjusted hazard ratios (aHRs) of achievements of these endpoints by level of WMHs were estimated by using Cox models, accounting for other relevant clinical and imaging factors.ResultsIndividuals with moderate/severe WMHs (n = 86, 41%) had greater balance and gait disorders and were more often fallers than others (n = 124, 59%). Overall, they had worse and slower recovery of single limb stance and independent gait (P < 0.001). Moderate/severe WMHs was the most detrimental factor for recovery of balance (aHR 0.46, 95% confidence interval [CI] 0.32–0.68, P < 0.001) and gait (0.51, 0.35–0.74, P < 0.001), along with age, stroke severity, lesion volume and disrupted corticospinal tract. With cerebral infarct, endovascular treatments had an independent positive effect, both on the recovery of balance (aHR 1.65, 95% CI 1.13–2.4, P = 0.009) and gait (1.78, 1.24–2.55, P = 0.002).ConclusionsWMHs magnify balance and gait disorders after stroke and worsen their recovery. They should be better accounted for in post-stroke rehabilitation, especially to help establish a prognosis of mobility.ClinicalTrials.gov registrationNCT03203109.     

Paravertebral spinal injection for the treatment of patients with degenerative facet osteoarthropathy: Evidence of motor performance improvements based on objective assessments

BackgroundThis study examined short- and long-term improvements in motor performance, quantified using wearable sensors, in response to facet spine injection in degenerative facet osteoarthropathy patients.MethodsAdults with confirmed degenerative facet osteoarthropathy were recruited and were treated with medial or intermediate branch block injection. Self-report pain, health condition, and disability (Oswestry), as well as objective motor performance measures (gait, balance, and timed-up-and-go) were obtained in five sessions: pre-surgery (baseline), immediately after the injection, one-month, three-month, and 12-month follow-ups. Baseline motor performance parameters were compared with 10 healthy controls.FindingsThirty patients (age = 50 (14) years) and 10 controls (age = 46 (15) years) were recruited. All motor performance parameters were significantly different between groups. Results showed that average pain and Oswestry scores improved by 51% and 24%, respectively among patients, only one month after injection. Similarly, improvement in motor performance was most noticeable in one-month post-injection measurements; most improvements were observed in gait speed (14% normal walking, P < 0.02), hip sway within balance tests (63% eyes-open P < 0.01), and turning velocity within the timed-up-and-go test (28%, P < 0.02). Better baseline motor performance led to better outcomes in terms of pain relief; baseline turning velocity was 18% faster among the responsive compared to the non-responsive patients.InterpretationsSpinal injection can temporarily (one to three months) improve motor performance in degenerative facet osteoarthropathy patients. Successful pain relief in response to treatment is independent of demographic characteristics and initial pain but dependent on baseline motor performance. Immediate self-reported pain relief is unrelated to magnitude of gradual improvement in motor performance.