Progressive resistance training and dynamic alignment in osteoarthritis: A single-blind randomised controlled trial

Background

We hypothesised that high intensity progressive resistance training would improve lower limb dynamic alignment and function (lower knee adduction moment, increased muscle strength, and fewer knee osteoarthritis symptoms).

Methods

Women (n = 54) with osteoarthritis in at least one knee were randomised into a 6-month resistance training or a sham-exercise program. The primary outcomes were dynamic shank and knee adduction angles and knee adduction moment of the most symptomatic knee measured with quantitative gait analysis. Secondary outcomes were muscle strength, gait speed, and osteoarthritis symptoms.

Findings

Dynamic alignment and knee adduction moment did not change over time or between groups. Muscle strength improved in both groups over time, but significantly more in the resistance training group (P = 0.002). By contrast, gait velocity and pain improved over time (P ≤ 0.009) in both groups. Improvements in shank adduction angle were related to improvements in self-reported disability (r = 0.381, P = 0.015), but not to changes in muscle strength, gait velocity, or pain (all P > 0.05).

Interpretations

Although muscle strength improved significantly more in the PRT group, the hypothesised reduction in knee adduction moment, shank and knee adduction angles were not evident after either exercise modality. However, improvements in disability and shank adduction angle were significantly directly related. Initial alignment should be used to stratify this population into separate groups when designing future trials and alternative modes of training investigated to potentially enhance beneficial alterations in knee alignment.     

Effect of specific gait modifications on medial knee loading,metabolic cost and perception of task difficulty

Background

The metabolic cost and cognitive demand of altering natural gait have not been well studied. The purpose of this investigation was to assess three modified patterns – toe out, ipsilateral trunk lean and a medial weight shift at the foot – on the basis of 1) medial knee joint load reduction, 2) metabolic cost of performance and 3) subject perception of task difficulty.

Methods

12 healthy individuals underwent 3 dimensional motion analysis and metabolic testing to assess the gait mechanics and energy expenditure of natural gait and the three experimental gait patterns, performed to a self-selected moderate degree. Walking speed was controlled. Perceived workload was assessed using the NASA Task Load Index.

Findings

Trunk lean significantly reduced first peak knee adduction moment (↓32%, P < 0.001) as well as KAM impulse (↓35%, P < 0.001), but was costly in terms of energy expenditure (↑11%, P < 0.001) and perceived workload (↑1178%, P < 0.001). A moderate toe-out pattern significantly reduced the second peak knee adduction moment (↓32%, P < 0.001) and KAM impulse (↓14%, P = 0.026), but had no effect on the first peak. Conversely, toe-out was least demanding in terms of additional energy expenditure (↑2%, P = 0.001) and perceived workload (↑314%, P = 0.001). Medial shift did not reduce knee adduction moment.

Interpretation

The prioritization of joint load reduction versus additional metabolic and cognitive demands could play a substantial role in the clinical decision making process of selecting a modified gait pattern.     

Altered tibiofemoral joint contact mechanics and kinematics in patients with knee osteoarthritis and episodic complaints of joint instability

Background

To evaluate knee joint contact mechanics and kinematics during the loading response phase of downhill gait in knee osteoarthritis patients with self-reported instability.

Methods

Forty-three subjects, 11 with medial compartment knee osteoarthritis and self-reported instability (unstable), 7 with medial compartment knee osteoarthritis but no reports of instability (stable), and 25 without knee osteoarthritis or instability (control) underwent Dynamic Stereo X-ray analysis during a downhill gait task on a treadmill.

Findings

The medial compartment contact point excursions were longer in the unstable group compared to the stable (P = 0.046) and the control groups (P = 0.016). The peak medial compartment contact point velocity was also greater for the unstable group compared to the stable (P = 0.047) and control groups (P = 0.022). Additionally, the unstable group demonstrated a coupled movement pattern of knee extension and external rotation after heel contact which was different than the coupled motion of knee flexion and internal rotation demonstrated by stable and control groups.

Interpretation

Our findings suggest that knee joint contact mechanics and kinematics are altered during the loading response phase of downhill gait in knee osteoarthritis patients with self-reported instability. The observed longer medial compartment contact point excursions and higher velocities represent objective signs of mechanical instability that may place the arthritic knee joint at increased risk for disease progression. Further research is indicated to explore the clinical relevance of altered contact mechanics and kinematics during other common daily activities and to assess the efficacy of rehabilitation programs to improve altered joint biomechanics in knee osteoarthritis patients with self-reported instability.     

Comparison of Mirror,Raw Video,and Real-Time Visual Biofeedback for Training Toe-Out Gait in Individuals With Knee Osteoarthritis

Objective

To compare performance error and perceived difficulty during toe-out gait modification in people with knee osteoarthritis (OA) across 3 different types of visual feedback: mirror, raw video, and real-time biofeedback of toe-out angle.

Design

Repeated-measures, within-subject trial.

Setting

University motion analysis laboratory.

Participants

Individuals with knee OA (N=20; 11 women; mean age, 65.4±9.8y) participated in this study. Seven participants had mild knee OA, 9 had moderate knee OA, and 4 had severe knee OA.

Interventions

Participants were trained to walk on a treadmill while matching a target indicating a 10° increase in stance phase toe-out compared with toe-out angle measured during self-selected walking. The target was provided visually via the 3 types of feedback listed above and were presented in a random order.

Main Outcome Measures

Kinematic data were collected and used to calculate the difference between the target angle and the actual performed angle for each condition (toe-out performance error). Difficulty was assessed using a numerical rating scale (0–10) provided verbally by participants.

Results

Toe-out performance error was significantly less when using the real-time biofeedback method than when using the other 2 methods (P=.025; mean difference vs mirror=2.05°; mean difference vs raw video=1.51°). Perceived difficulty was not statistically different between the groups (P=.51).

Conclusions

Although statistically significant, the 2° difference in toe-out gait performance error may not necessitate the large economic and personnel costs of real-time biofeedback as a means to modify movement in clinical or research settings.     

Are the kinematics of the knee joint altered during the loading response phase of gait in individuals with concurrent knee osteoarthritis and complaints of joint instability? A dynamic stereo X-ray study

Background

Joint instability has been suggested as a risk factor for knee osteoarthritis and a cause of significant functional decline in those with symptomatic disease. However, the relationship between altered knee joint mechanics and self-reports of instability in individuals with knee osteoarthritis remains unclear.

Methods

Fourteen subjects with knee osteoarthritis and complaints of joint instability and 12 control volunteers with no history of knee disease were recruited for this study. Dynamic stereo X-ray technology was used to assess the three-dimensional kinematics of the knee joint during the loading response phase of gait.

Findings

Individuals with concurrent knee osteoarthritis and joint instability demonstrated significantly reduced flexion and internal/external rotation knee motion excursions during the loading response phase of gait (P < 0.01), while the total abduction/adduction range of motion was increased (P < 0.05). In addition, the coronal and transverse plane alignment of the knee joint at initial contact was significantly different (P < 0.05) for individuals with concurrent knee osteoarthritis and joint instability. However, the anteroposterior and mediolateral tibiofemoral joint positions at initial contact and the corresponding total joint translations were similar between groups during the loading phase of gait.

Interpretations

The rotational patterns of tibiofemoral joint motion and joint alignments reported for individuals with concurrent knee osteoarthritis and joint instability are consistent with those previously established for individuals with knee osteoarthritis. Furthermore, the findings of similar translatory tibiofemoral motion between groups suggest that self-reports of episodic joint instability in individuals with knee osteoarthritis may not necessarily be associated with adaptive alterations in joint arthrokinematics.     

The effects of pediatric obesity on dynamic joint malalignment during gait

Background

There is a greater prevalence of lower extremity malalignment in obese children during static posture; however, there has been less examination of dynamic joint function in this cohort. Therefore, the purpose of this study was to determine kinematic differences that exist between obese and non-obese children that would support previously reported static joint malalignment.

Methods

Forty children were classified as obese (n = 20) or non-obese (n = 20). Lower extremity joint kinematics were collected during five walking trials at a self-selected pace. Peak joint displacement and amount of joint motion throughout the gait cycle (calculated as the integrated displacement curve) were analyzed for group differences.

Findings

Non-obese children had greater peak knee and hip extension during gait; however, there were no group differences in the integrated sagittal displacement curve. Obese children had greater peak angular displacement and integrals of angular displacement for peak hip adduction, hip internal rotation, and foot abduction (toe-out) than non-obese children. Obese children also had greater peak knee external rotation than non-obese children.

Interpretation

Non-obese children showed greater range of motion in the sagittal plane, particularly at the hip and knee. Frontal and transverse plane differences suggest that obese children function in a more genu valgum position than non-obese children. Static measures of genu valgum have been previously associated with pediatric obesity; the findings indicate that there are also dynamic implications of said malalignment in obese children. Genu valgum presents increased risk of osteoarthritis for obese children and should be considered when prescribing weight bearing exercise to this cohort.     

Correlations among measures of knee stiffness,gait performance and complaints in individuals with knee osteoarthritis

Background

Stiffness is a common complaint in individuals with knee osteoarthritis and is a component of the osteoarthritis diagnosis. Yet the relationship between stiffness and function is poorly understood and methods to quantify stiffness are limited.

Methods

Using a cross-sectional observational design with 66 subjects with knee osteoarthritis, stiffness and damping coefficients were calculated from a relaxed knee oscillation procedure. Gait parameters were measured using an electronic walkway. Self-reported pain, stiffness, and function were measured with the Western Ontario and McMaster Osteoarthritis Index. Correlation and Alexander's normalized-t approximation analyses were used to assess associations among the variables. Subset analysis was performed on subjects with and without tibiofemoral joint crepitus.

Findings

Slight to moderate correlations existed between stiffness and damping coefficients and most gait parameters ((| r | = 0.30–0.56; P < .05) and between Western Ontario and McMaster Osteoarthritis Index scores and all gait parameters (| r | = 0.35–0.62; P < .05). The damping coefficient was only slightly associated with patient-rated Western Ontario and McMaster Osteoarthritis Index stiffness subscale scores. Subset analysis revealed significant correlations that differed between those with and without crepitus.

Interpretation

These findings suggest that laboratory measured stiffness and damping coefficients, Western Ontario and McMaster Osteoarthritis Index scores and gait-related measurements assess different aspects related to movement in individuals with knee osteoarthritis. Stiffness and damping coefficients may offer the ability to explain gait changes in the knee that are independent of a person's perceptions particularly in the early stages of the disease.     

Sagittal plane joint loading is related to knee flexion in osteoarthritic gait

Background

High mechanical loading has been consistently linked with medial tibiofemoral osteoarthritis, and is considered to play a central role in the pathogenesis of the disease. Evidence from healthy adults indicates that knee flexion kinematics may influence knee load. The purpose of this study therefore, was to investigate the association between knee flexion kinematics and indicators of joint loading during walking (peak moments and vertical ground reaction force), in individuals with medial tibiofemoral osteoarthritis.

Methods

In this cross-sectional study, 89 participants with painful medial tibiofemoral osteoarthritis completed three-dimensional walking gait analysis to measure stance phase ground reaction forces, knee joint moments, and knee flexion kinematics.

Findings

In stepwise regression, greater knee flexion excursion was associated with higher peak vertical ground reaction force, accounting for 10% of its variance (B = 0.62 [95% CI 0.34, 0.89], P < 0.001). Greater peak knee flexion was associated with a higher flexion moment, accounting for 44% of its variance (B = 0.12 [95% CI 0.09, 0.15], P < 0.001). No association was found between the knee adduction moment and knee flexion kinematics during walking.

Interpretation

Our data suggest that greater knee flexion is associated with higher joint loads in the sagittal plane (i.e. a higher peak knee flexion moment). However, knee flexion kinematics were not associated with the knee adduction moment — a proxy measure of medial compartment knee load. Thus, high knee flexion should be considered an undesirable gait characteristic with respect to knee load in individuals with medial tibiofemoral osteoarthritis.     

Gastrocnemius inflexibility on foot progression angle and ankle kinetics during walking

Background

Gastrocnemius inflexibility is a major problem in many orthopedic and neurological patients. Clinically, inflexible gastrocnemius muscles interfere with the performance of functional abilities and associate with many overuse injuries of the lower extremity. The purpose of this study was to investigate the effects of the gastrocnemius inflexibility on the foot progression angle and ankle kinetics during walking.

Methods

There were 50 subjects, 23 patients with the inflexible gastrocnemius and 27 normal subjects, included in this investigation. Participants were asked to walk at two preset cadences of 100 steps/min and 140 steps/min. Data were collected from a motion analysis system and force plates. Kinematic and kinetic variables of gait were computed and analyzed.

Findings

Compared with the control group, greater toe-out foot progression angle (P = 0.001, effect size = 0.314) and knee external rotation (P = 0.008, effect size = 0.136) were found in the inflexible group during stance phase. Furthermore, significant greater plantarflexion moment (P = 0.032, effect size = 0.093) and medial ground reaction force (P = 0.009, effect size = 0.135) during midstance were discovered in the inflexible group.

Interpretation

The present results indicate that gastrocnemius inflexibility might bring about the changes in the joint angles, ankle moments and ground reaction forces. The abnormal joint alignment in the lower extremities and greater force upon joint tissue might be significant for the clinical considerations on soft tissue injuries for the patients with inflexible gastrocnemius muscles.     

Frontal plane compensatory strategies associated with self-selected walking speed in individuals post-stroke

Background

Approximately two out of three individuals post-stroke experience walking impairments. Frontal plane compensatory strategies (i.e. pelvic hiking and circumduction) are observed in post-stroke gait in part to achieve foot clearance in response to reduced knee flexion and ankle dorsiflexion. The objective of this study was to investigate the relationship between self-selected walking speed and the kinematic patterns related to paretic foot clearance during post-stroke walking.

Methods

Gait analysis was performed at self-selected walking speed for 21 individuals post-stroke. Four kinematic variables were calculated during the swing phase of the paretic limb: peak pelvic tilt (pelvic hiking), peak hip abduction (circumduction), peak knee flexion, and peak ankle dorsiflexion. Paretic joint angles were analyzed across self-selected walking speed as well as between functionally relevant ambulation categories (Household < 0.4 m/s, Limited Community 0.4–0.8 m/s, Community > 0.8 m/s).

Findings

While all subjects exhibited similar foot clearance, slower walkers exhibited greater peak pelvic hiking and less knee flexion, ankle dorsiflexion, and circumduction compared to faster walkers (P < .05). Additionally, four of the fastest walkers compensated for poor knee flexion and ankle dorsiflexion through large amounts of circumduction.

Interpretation

These findings suggest that improved gait performance after stroke, as measured by self-selected walking speed, is not necessarily always accomplished through gait patterns that more closely resemble healthy gait for all variables. It appears the ability to walk fast is achieved by either sufficient ankle dorsiflexion and knee flexion to achieve foot clearance or the employment of circumduction to overcome a deficit in either ankle dorsiflexion or knee flexion.     

Hip abductor function in individuals with medial knee osteoarthritis: Implications for medial compartment loading during gait

Background

Hip abductor muscles generate moments of force that control lower extremity frontal plane motion. Strengthening these muscles has been a recent trend in therapeutic intervention studies for knee osteoarthritis. The current study investigated the relationship between hip abductor muscle function (strength and activation) and the net external knee adduction moment during gait in those with medial compartment knee osteoarthritis.

Methods

54 individuals with moderate knee osteoarthritis walked at their self-selected velocity while gluteus medius electromyograms, segment motions and ground reaction forces were recorded. Net external knee adduction moment (KAM) and linear enveloped electromyographic profiles were calculated. Peak KAM was determined and then principal component analyses (PCA) were applied to KAM and electromyographic profiles. Isometric hip abductor strength, anthropometrics and gait velocity were measured. Multiple regression models evaluated the relationship between walking velocity, hip abductor strength, electromyographic variables recorded during gait and KAM waveform characteristics.

Findings

Minimal peak KAM variance was explained by abductor strength (R² = 9%, P = 0.027). PCA-based KAM waveform characteristics were not explained by abductor strength. Overall gluteus medius amplitude (PP1-scores) was related to a reduction in the bi-modal KAM (PP3-scores) pattern (R² = 16%, P = 0.003).

Interpretation

There was no clear relationship between hip abductor muscle strength and specific amplitude and temporal KAM characteristics. Higher overall gluteus medius activation amplitude was related to a sustained KAM during mid-stance. 84 to 90% of the variance in KAM waveform characteristics was not explained by hip abductor muscle function showing hip abductor muscle function has minimal association to KAM characteristics.     

Impact of foot progression angle on the distribution of plantar pressure in normal children

Background

Plantar pressure distribution during walking is affected by several gait factors, most especially the foot progression angle which has been studied in children with neuromuscular diseases. However, this relationship in normal children has only been reported in limited studies. The purpose of this study is to clarify the correlation between foot progression angle and plantar pressure distribution in normal children, as well as the impacts of age and sex on this correlation.

Methods

This study retrospectively reviewed dynamic pedobarographic data that were included in the gait laboratory database of our institution. In total, 77 normally developed children aged 5–16 years who were treated between 2004 and 2009 were included. Each child's footprint was divided into 5 segments: lateral forefoot, medial forefoot, lateral midfoot, medial midfoot, and heel. The percentages of impulse exerted at the medial foot, forefoot, midfoot, and heel were calculated.

Findings

The average foot progression angle was 5.03° toe-out. Most of the total impulse was exerted on the forefoot (52.0%). Toe-out gait was positively correlated with high medial (r = 0.274; P < 0.001) and forefoot impulses (r = 0.158; P = 0.012) but negatively correlated with midfoot impulse (r = − 0.273; P < 0.001). The moderating effects of age and sex on these correlations were insignificant.

Interpretation

Foot progression angle demonstrates significant impact on the distribution of foot pressure, regardless of age or sex. Foot progression angle should be taken into consideration when conducting pedobarographic examinations and balancing plantar pressure as part of the treatment of various foot pathologies.     

Gait analysis after bi-compartmental knee replacement

Background

It is reported that a majority of the patients with knee osteoarthritis have cartilage degeneration in medial and patellofemoral compartments. A bi-compartmental knee replacement system was designed to treat osteoarthritis at medial and patellofemoral compartments. To date, there is very little information regarding the knee mechanics during gait after bi-compartmental knee replacement. The purpose of the study was to evaluate knee strength and mechanics during level walking after knee replacement.

Methods

Ten healthy control subjects and eight patients with unilateral bi-compartmental knee replacement participated in the study. Maximal isokinetic concentric knee extension strength was evaluated. 3D kinematic and kinetic analyses were conducted for level walking. Paired Student t-test was used to determine difference between surgical and non-involved limbs. One way MANOVA was used to determine difference between surgical and control groups.

Findings

The surgical knee exhibited less peak torque and initial abduction moment than both the non-involved and control limbs (P < 0.05). The non-involved limb had less knee extension at stance and greater knee extensor moment during push-off than both the surgical and control limbs (P < 0.05). No differences were found for other typical knee mechanics among the surgical, non-involved, and control limbs during walking (P > 0.05).

Interpretations

Patients with bi-compartmental knee replacement exhibited good frontal plane knee mechanics and were able to produce the same level of knee extensor moment as healthy control limbs during walking. While showing some compensatory patterns during walking, patients with bi-compartmental knee replacement largely exhibited normal gait patterns and knee mechanics.     

Potential interaction of experimental knee pain and laterally wedged insoles for knee off-loading during walking

Background

Laterally wedged insoles are one of the gait modifications potentially slowing down progression of medial knee osteoarthritis. Clinical studies have, however, found large individual differences in the biomechanical effect and an insufficient pain reduction. To clarify if and how pain mediates mechanical changes during gait the current study investigated how acute experimental knee pain changes the mechanical effect of laterally wedged insoles in healthy subjects during walking.

Methods

3D gait analysis was carried out for twelve healthy individuals. The study followed a cross-over design and data were collected with both a neutral and a 10-degree laterally wedged insole with experimental pain induced by hypertonic and isotonic saline injections into the infrapatellar fat pad. Peak knee adduction moment was the primary outcome. A repeated ANOVA (analysis of variance) was used to evaluate the relationship between the factors wedge, condition and test number.

Findings

Wedges significantly reduced peak knee adduction moment but experimental knee pain did only marginally affect its magnitude in either condition. While frontal plane mechanics were relatively unaffected by pain, the sagittal plane knee extension moment increased with laterally wedging (P = 0.008), whereas late knee flexion moment was reduced by experimental knee pain (P = 0.04).

Interpretation

The effect of laterally wedged insoles in attenuating knee adduction moment during walking is independent of experimental knee pain. The present study provides evidence that subjects with experimental knee pain reduce knee loading by reducing extension moment, whereas lateral wedges have the opposite effect and increase the extension moment.     

Activity progression for anterior cruciate ligament injured individuals

Background

Functional exercises are important in the rehabilitation of anterior cruciate ligament deficient and reconstructed individuals but movement compensations and incomplete recovery persist. This study aimed to identify how tasks pose different challenges; and evaluate if different activities challenge patient groups differently compared to controls.

Methods

Motion and force data were collected during distance hop, squatting and gait for 20 anterior cruciate ligament deficient, 21 reconstructed and 21 controls.

Findings

Knee range of motion was greatest during squatting, intermediate during hopping and smallest during gait (P < 0.01). Peak internal knee extensor moments were greatest during distance hop (P < 0.01). The mean value of peak knee moments was reduced in squatting and gait (P < 0.01) compared to hop. Peak internal extensor moments were significantly larger during squatting than gait and peak external adductor moments during gait compared to squatting (P < 0.01). Fluency was highest during squatting (P < 0.01). All patients demonstrated good recovery of gait but anterior cruciate ligament deficient adopted a strategy of increased fluency (P < 0.01). During squatting knee range of motion and peak internal knee extensor moment were reduced in all patients (P < 0.01). Both anterior cruciate ligament groups hopped a shorter distance (P < 0.01) and had reduced knee range of motion (P < 0.025). Anterior cruciate ligament reconstructed had reduced fluency (P < 0.01).

Interpretation

Distance hop was most challenging; squatting and gait were of similar difficulty but challenged patients in different ways. Despite squatting being an early, less challenging exercise, numerous compensation strategies were identified, indicating that this may be more challenging than gait.     

Bilateral coordination and gait symmetry after body-weight supported treadmill training for persons with chronic stroke

Background

Locomotor interventions are commonly assessed using functional outcomes, but these outcomes provide limited information about changes toward recovery or compensatory mechanisms. The study purposes were to examine changes in gait symmetry and bilateral coordination following body-weight supported treadmill training in individuals with chronic hemiparesis due to stroke and to compare findings to participants without disability.

Methods

Nineteen participants with stroke (> 6 months) who ambulated between 0.4 and 0.8 m/s and 22 participants without disability were enrolled in this repeated-measures study. The stroke group completed 24 intervention sessions over 8 weeks with 20 minutes of walking/session. The non-disabled group served as a comparison for describing changes in symmetry and coordination. Bilateral 3-dimensional motion analysis and gait speed were assessed across 3 time points (pre-test, immediate post-test, and 6-month retention). Continuous relative phase was used to evaluate bilateral coordination (thigh–thigh, shank–shank, foot–foot) and gait symmetry was assessed with spatiotemporal ratios (step length, swing time, stance time).

Findings

Significant improvements in continuous relative phase (shank–shank and foot–foot couplings) were found at post-test and retention for the stroke group. Significant differences in spatiotemporal symmetry ratios were not found over time. Compared to the non-disabled group, changes in bilateral coordination moved in the direction of normal recovery. Most measures of continuous relative phase were more responsive to change after training than the spatiotemporal ratios.

Interpretations

After body-weight supported treadmill training, the stroke group made improvements toward recovery of normal bilateral coordination. Bilateral coordination and gait symmetry measures may assess different aspects of gait.     

Ankle range of motion is key to gait efficiency in adolescents with cerebral palsy

Background

Gait in young people with cerebral palsy is inefficient and there is a lack of relevant indicators for monitoring the problem. In particular, the impact of gait kinematics on gait efficiency is not well documented. The aim of this study is to examine the relationship between gait efficiency, gait kinematics, lower limb muscle strength, and muscular spasticity in adolescents with cerebral palsy.

Methods

Ten ambulatory adolescents with spastic cerebral palsy were recruited. The energy expenditure index during gait, gait kinematics, flexion and extension knee isometric muscle strength, and quadriceps spasticity were assessed.

Findings

Energy expenditure index (1.5 (0.7) beats/m) was strongly correlated with the ankle and knee flexion/extension ranges of motion (r = −0.82, P < 0.01 and r = −0.70, P < 0.02, respectively) and also with maximal plantar flexion (r = 0.74, P < 0.05) during gait. Knee flexion strength was the only strength measurement correlated with energy expenditure index (r = −0.85; P < 0.01).

Interpretation

This study suggests that ankle and knee flexion/extension ranges of motion during gait are key kinematics factors in gait efficiency in adolescents with cerebral palsy.     

The effect of anti-pronation foot orthoses on hip and knee kinematics and muscle activity during a functional step-up task in healthy individuals: A laboratory study

Background

Greater frontal and transverse plane hip and knee motion, and delayed gluteus medius and vastus medialis oblique activation have frequently been identified in patellofemoral pain syndrome populations, whilst prefabricated anti-pronation foot orthoses have been reported to reduce symptoms. The aim of the study was to evaluate the effects of such orthoses on hip and knee kinematics, gluteal and vasti muscle activity, kinematic and electromyographic interactions alongside correlations with specific clinical measures.

Methods

Eighteen asymptomatic individuals (11 male 7 female) had measures taken of static foot posture and ankle range of motion. Hip muscle activity and kinematics were measured using electromyography and an active motion capture system during a step-up task. Order of testing with or without orthoses was determined using a coin toss.

Findings

Between condition paired t-tests indicated significantly reduced peak hip adduction angles (1.56°, P < 0.05) and significantly reduced knee internal rotation (1.3°, P < 0.05) in the orthoses condition. Reduced ankle dorsiflexion range of motion correlated with a reduction in hip adduction following the orthoses intervention (r = 0.59, P = 0.013).

Interpretation

The effects of prefabricated orthoses may be partially explained by kinematic alterations that occur proximal to the foot in the kinetic chain. These clinically and biomechanically relevant effects appear more evident in those with reduced underlying ankle motion. Further research is indicated using a symptomatic population to explore the clinical relevance of these observations.     

Differences in gait pattern parameters between medial and anterior knee pain in patients with osteoarthritis of the knee

Background

Patients with osteoarthritis of the knee have unique spatiotemporal gait alterations. These gait changes have not yet been differentiated according to the location of knee pain. The purpose of this study was to compare the gait patterns of patients with symptomatic knee osteoarthritis that exhibit either anterior or medial joint pain.

Methods

240 Patients with knee osteoarthritis were evaluated at one therapy center. Patients were divided into two groups according to the location of greatest pain in their worse knee. Patients underwent a computerized spatiotemporal gait analysis. Differences in gait patterns between the two knee pain locations were also examined within each gender.

Findings

Compared with patients with pain in the anterior knee compartment, those with pain in the medial knee compartment exhibited a significantly slower walking speed (P < 0.01), shorter step length (P < 0.01), lower single-limb-support phase (P < 0.01). These differences are witnessed mainly between the females in each group, whereas males differed only in single-limb-support.

Interpretation

The results of this study suggested underlying gait differences in the nature of medial and anterior knee pain. Furthermore, gender differences in gait may exist between patients with medial knee pain compared to patients with anterior knee pain.     

Peak knee adduction moment during gait in anterior cruciate ligament reconstructed females

Background

Recent work has shown that anterior cruciate ligament reconstructed patients exhibit an increased peak knee adduction moment during walking gait compared to healthy controls. An increased peak knee adduction moment has been suggested to be a potential mechanism of degeneration for knee osteoarthritis. The few studies in this area have not considered an exclusively female anterior cruciate ligament reconstructed group. This study tested the hypothesis that female anterior cruciate ligament-reconstructed patients would have higher peak knee adduction moments than controls.

Methods

Peak knee adduction moment during walking was compared between a group of anterior cruciate ligament reconstructed females and a group of female activity matched controls over ten 15 m walking trials in a laboratory at a self-selected pace.

Findings

Peak knee adduction moment was lower for the anterior cruciate ligament reconstructed group (N = 17, M = 0.31 Nm/kg·m, SD = 0.08) than for the control group (N = 17, M = 0.41 Nm/kg·m, SD = 0.12; t(32) = 2.483, p = 0.010, one-tailed, eta squared effect size = 0.16).

Interpretation

A group of female anterior cruciate ligament reconstructed subjects did not exhibit a gait characteristic which has been suggested to be associated with knee osteoarthritis development and has been shown to be present in male and mixed sex anterior cruciate ligament reconstructed populations previously.