A preliminary comparison of myoelectric and cyclic control of an implanted neuroprosthesis to modulate gait speed in incomplete SCI

Objective

Explore whether electromyography (EMG) control of electrical stimulation for walking after incomplete spinal cord injury (SCI) can affect ability to modulate speed and alter gait spatial-temporal parameters compared to cyclic repetition of pre-programmed stimulation.

Design

Single case study with subject acting as own concurrent control.

Setting

Hospital-based biomechanics laboratory.

Participants

Single subject with C6 AIS D SCI using an implanted neuroprosthesis for walking.

Interventions

Lower extremity muscle activation via an implanted system with two different control methods: (1) pre-programmed pattern of stimulation, and (2) EMG-controlled stimulation based on signals from the gastrocnemius and quadriceps.

Outcome measures

Gait speed, distance, and subjective rating of difficulty during 2-minute walks. Range of walking speeds and associated cadences, stride lengths, stride times, and double support times during quantitative gait analysis.

Results

EMG control resulted in statistically significant increases in both walking speed and distance (P < 0.001) over cyclic stimulation during 2-minute walks. Maximum walking speed with EMG control (0.48 m/second) was significantly (P < 0.001) faster than the fastest automatic pattern (0.39 m/second), with increased cadence and decreased stride and double support times (P < 0.000) but no change in stride length (z = −0.085; P = 0.932). The slowest walking with EMG control (0.25 m/second) was virtually indistinguishable from the slowest with automatic cycling (z = −0.239; P = 0.811).

Conclusion

EMG control can increase the ability to modulate comfortable walking speed over pre-programmed cyclic stimulation. While control methods did not differ at the lowest speed, EMG-triggered stimulation allowed significantly faster walking than cyclic stimulation. The expanded range of available walking speeds could permit users to better avoid obstacles and naturally adapt to various environments. Further research is required to definitively determine the robustness, generalizability, and functional implications of these results.     

Very short-term effect of brace wearing on gait in adolescent idiopathic scoliosis girls

Purpose

Adolescent idiopathic scoliotic (AIS) deformity induces excessive oxygen consumption correlated to a bilateral increase of lumbo-pelvic muscles timing activity (EMG) during gait. Wearing a brace, the usual treatment for AIS, by supporting the spine and the pelvis, would generate lumbo-pelvic muscular relaxation and consequently reduce excessive oxygen consumption. The purpose of this study was to evaluate the short-term effect of bracing on gait biomechanics in scoliotic spine when compared with normal braced spine.

Methods

Thirteen healthy volunteers were compared to 13 AIS girls. In both samples, gait analysis was assessed using a three-dimensional motion analysis, including synchronous kinematic, electromyographic, mechanical and energy measurements, first without brace, then wearing a brace.

Results

For scoliotic patients, comparison of in-brace and out-brace situations revealed a significant decrease of frontal pelvis (p < 0.001), hip (p < 0.001) and shoulder (p = 0.004) motion in brace associated with a significant reduction of pelvis rotation (p = 0.003). However, the brace did not change significantly the lumbo-pelvic muscle activity duration (EMG) or the mechanical and energetic parameters. Transversal pelvis motion was reduced by 39 % (p = 0.04), frontal hip and shoulder motions by 23 % (p = 0.004) and 30 % (p = 0.01) respectively, and energy cost of walking remained increased by 37 % in braced AIS girls relatively to braced healthy subjects. Mechanical and electromyographic variables were not significantly different between the two braced populations during gait except for the gluteus medius muscle that showed bilaterally an increase of duration of electrical activity in healthy subjects and contrarily a decrease in AIS patients (healthy: −3.5 ± 9.6 % of gait cycle vs. scoliotic: 3.7 ± 7.7 % of gait cycle; p = 0.04).

Conclusions

Bracing changed neither the oxygen consumption nor the timing of the lumbo-pelvic muscles activity in both groups during gait. However, in brace the timing activity of bilateral gluteus medius muscles tended to decrease in AIS patients and increase in healthy subjects. Moreover, braced AIS patients had more restricted frontal hips and shoulder motion as well as pelvis rotation than braced healthy subjects.     

Gait impairment in cervical spondylotic myelopathy: comparison with age- and gender-matched healthy controls

Introduction

Gait impairment is a primary symptom of cervical spondylotic myelopathy (CSM); however, little is known about specific kinetic and kinematic gait parameters. The objectives of the study were: (1) to compare gait patterns of people with untreated CSM to those of age- and gender-matched healthy controls; (2) to examine the effect of gait speed on kinematic and kinetic parameters.

Materials and methods

Sixteen patients with CSM were recruited consecutively from a neurosurgery clinic, and 16 healthy controls, matched to age (±5 years) and gender, were recruited for comparison. Patients and controls underwent three-dimensional gait analysis using a Vicon^® motion analysis system, at self-selected speed over a 10-m track. Controls were also assessed at the speed of their CSM match.

Results

At self-selected speed, the CSM group walked significantly more slowly, with shorter stride lengths and longer double support duration. They showed significant decreases in several kinematic and kinetic parameters, including sagittal range of motion at the hip and knee, ankle plantarflexion, anteroposterior ground reaction force (GRF) at toe-off, power absorption at the knee in loading response and terminal stance, and power generation at the ankle. At matched speed, the CSM group showed significant decreases in knee flexion during swing, total sagittal knee range of motion, peak ankle plantarflexion and anteroposterior GRF.

Conclusion and implications

The findings suggested that people with CSM have significant gait abnormalities that have not been previously reported. In particular, there are key differences in the motor strategies used in the terminal stance phase of gait that cannot be explained by speed alone.     

A report of anticipated benefits of functional electrical stimulation after spinal cord injury

Background

Functional electrical stimulation (FES) has been regularly used to offset several negative body composition and metabolic adaptations following spinal cord injury (SCI). However, the outcomes of many FES trials appear to be controversial and incoherent.

Objective

To document the potential consequences of several factors (e.g. pain, spasms, stress and lack of dietary control) that may have attenuated the effects on body composition and metabolic profile despite participation in 21 weeks of FES training.

Participant

A 29-year-old man with T6 complete SCI participated in 21 weeks of FES, 4 days per week.

Methods

Prior to and following training, the participant performed arm-crank-graded exercise testing to measure peak VO₂. Tests conducted included anthropometrics and dual energy X-ray absorptiometry body composition assessments, resting energy expenditure, plasma lipid profiles and intravenous glucose tolerance tests.

Results

The participant frequently reported increasing pain, stress and poor eating habits. VO₂ peak decreased by 2.4 ml/kg/minute, body mass increased by 8.5 kg, and body mass index increased from 25 to 28 kg/m². Waist and abdominal circumferences increased by 2–4 cm, while %fat mass increased by 5.5%. Absolute increases in fat mass and fat-free mass of 8.4 and 1 kg, respectively, were reported. Fasting and peak plasma glucose increased by 12 and 14.5%, while lipid panel profiles were negatively impacted.

Conclusion

Failure to control for the listed negative emerging factors may obscure the expected body composition and metabolic profile adaptations anticipated from FES training.     

Functional electrical stimulation post-spinal cord injury improves locomotion and increases afferent input into the central nervous system in rats

Background

Functional electrical stimulation (FES) has been found to be effective in restoring voluntary functions after spinal cord injury (SCI) and stroke. However, the central nervous system (CNS) changes that occur in as a result of this therapy are largely unknown.

Objective

To examine the effects of FES on the restoration of voluntary locomotor function of the CNS in a SCI rat model.

Methods

SCI rats were instrumented with chronic FES electrodes in the hindlimb muscles and were divided into two groups: (a) FES therapy and (b) sedentary. At day 7 post-SCI, the animals were assessed for locomotion performance by using a Basso, Beattie and Bresnahan (BBB) scale. They were then anesthetized for a terminal in vivo experiment. The lumbar spinal cord and somatosensory cortex were exposed and the instrumented muscles were stimulated electrically. Associated neurovascular responses in the CNS were recorded with an intrinsic optical imaging system.

Results

FES greatly improved locomotion recovery by day 7 post-SCI, as measured by BBB scores (P < 0.05): (a) FES 10 ± 2 and (b) controls 3 ± 1. Furthermore, the FES group showed a significant increase (P < 0.05) of neurovascular activation in the spinal cord and somatosensory cortex when the muscles were stimulated between 1 and 3 motor threshold (MT).

Conclusion

Hind limb rehabilitation with FES is an effective strategy to improve locomotion during the acute phase post-SCI. The results of this study indicate that after FES, the CNS preserves/acquires the capacity to respond to peripheral electrical stimulation.     

Impact of triple pelvic osteotomy on contact stress pressure distribution in the hip joint

Purpose

We studied changes of contact stress distribution in the hip joint after Tonnis triple pelvic osteotomy applied in the treatment of dysplasia and hip joint incongruence in adolescents.

Methods

In a group of 75 patients, 54 (72 %) female, who underwent surgery by triple pelvic osteotomy in adolescence for developmental disorder of the hip and avascular necrosis of the femoral head, a three-dimensional hip joint model was used based on the radiography of the pelvis with hips. The following biomechanical parameters were calculated: resultant hip force normalised to body weight (R/Wb), inclination of the resultant hip force (θ−R), the position of the stress pole (θ), peak contact hip stress (Pmax), and peak contact hip stress normalised to body weight (Pmax/Wb). Gait quality was also assessed.

Results

After surgery the Wiberg CE angle was increased by 17.85° (114 %), resultant hip force normalised to body weight (R/Wb) was decreased by 0.107 (3.3 %), the position of the stress pole was shifted medially by 27.59° (63.5 %), and peak contact hip stress normalised to body weight (Pmax/Wb) was decreased by 2249.74 (55.9 %). Waddling gait was reduced from 17 (23.9 %) to four cases (5.6 %). All changes were statistically highly significant (p<0.01).

Conclusions

The effect of Tonnis triple pelvic osteotomy lies in the improvement of stress distribution across the acetabular cartilage of the hip joint, thus slowing down the degenerative damage of the hip joint.     

Comparison of wire and disc leads to activate the expiratory muscles in dogs

Objective

Respiratory complications account for a major cause of morbidity and mortality in subjects with spinal cord injury (SCI) due to paralysis of the expiratory muscles and the consequent inability to generate effective cough. We demonstrated previously that effective cough can be restored in SCI via spinal cord stimulation (SCS) with disc leads positioned on the lower thoracic and upper lumbar spinal cord via laminotomy incisions. In this study, the effectiveness of wire leads, which can be placed using minimally invasive techniques, to activate the expiratory muscles was evaluated.

Design

Animal study.

Setting

Research laboratory.

Animals

Dogs (n = 8).

Interventions

In separate trials, disc and wire leads were inserted onto the dorsal epidural space at the T9, T11, and L1 spinal cord levels. Effects of electrical stimulation with disc, single wire, and two wire leads placed in parallel were compared.

Outcome measures

Airway pressure generation following stimulation with disc and various configurations of wire leads were compared.

Results

Several different configurations of wire leads resulted in airway pressures that were similar to those generated with monopolar stimulation with disc leads (MSDLs). For example, combined monopolar stimulation with parallel wire leads at the T9 + T11 and T9 + L1 levels resulted in airway pressures that were 103.5 ± 6.4 and 101.9 ± 7.0%, respectively, of those achieved with MSDL. Bipolar stimulation with parallel wire leads at T9–T11 and T9–L1 resulted in airway pressures that were 94.2 ± 3.4 and 96.8 ± 5.0%, respectively, of the pressures achieved with MSDL. Other wire configurations were also evaluated, but were generally less effective.

Conclusion

These results suggest that specific configurations of wire leads, which can be placed via minimally invasive techniques, result in comparable activation of the expiratory muscles compared to disc leads and may be a useful technique to restore cough in persons with SCI.     

Screw-Home Movement of the Tibiofemoral Joint during Normal Gait: Three-Dimensional Analysis

Background

The purpose of this study was to evaluate the screw-home movement at the tibiofemoral joint during normal gait by utilizing the 3-dimensional motion capture technique.

Methods

Fifteen young males and fifteen young females (total 60 knee joints) who had no history of musculoskeletal disease or a particular gait problem were included in this study. Two more markers were attached to the subject in addition to the Helen-Hayes marker set. Thus, two virtual planes, femoral coronal plane (P_f) and tibial coronal plane (P_t), were created by Skeletal Builder software. This study measured the 3-dimensional knee joint movement in the sagittal, coronal, and transverse planes of these two virtual planes (P_f and P_t) during normal gait.

Results

With respect to kinematics and kinetics, both males and females showed normal adult gait patterns, and the mean difference in the temporal gait parameters was not statistically significant (p > 0.05). In the transverse plane, the screw-home movement occurred as expected during the pre-swing phase and the late-swing phase at an angle of about 17°. However, the tibia rotated externally with respect to the femur, rather than internally, while the knee joint started to flex during the loading response (paradoxical screw-home movement), and the angle was 6°.

Conclusions

Paradoxical screw-home movement may be an important mechanism that provides stability to the knee joint during the remaining stance phase. Obtaining the kinematic values of the knee joint during gait can be useful in diagnosing and treating the pathological knee joints.     

Gait knee kinematic alterations in medial osteoarthritis: three dimensional assessment

Purpose

Although kinematic changes in the sagittal plane of the osteoarthritic knee (OA) have been elucidated, very few studies have analysed changes in the frontal and horizontal planes. Therefore, the aim of this study was to investigate in vivo 3D knee kinematics during walking in patients wth knee OA.

Methods

Thirty patients with medial knee OA and a control group of similarly aged individuals were prospectively collected for this study. All participants were assessed with KneeKG^TM system while walking on a treadmill at a self-selected speed. In each trial, we calculated the angular displacment of flexion/extension, abduction/adduction and external/internal tibial rotation. Statistical analysis was performed to determine differences between the knee OA group and the control group.

Results

Patients with knee OA had reduced extension during the stance phase (p < 0.05; 8.5° and 4.4°, OA and control group, respectively) and reduced flexion during pushoff and initial swing phase (p  < 0.05; 41.9° and 49.4°, respectively). Adduction angle was consistently greater for OA patients (p  < 0.05; 3.4° and −0.9°, respectively). Frontal laxity for OA patients was positively correlated with varus deformity (r = 0.42, p < 0.05). There was a significant difference (p)  < 0.05 in tibial rotation during the midstance phase; OA patients retained a neutral position (−0.4°), while the control group presented internal tibial rotation (−2.2°).

Conclusion

Weight-bearing kinematics in medial OA knees differs from that of normal knees. The knee OA group showed an altered “screw-home” mechanism by decreased excursion in sagittal and axial tibial rotation and posterior tibial translation.     

Development of less invasive neuromuscular electrical stimulation model for motor therapy in rodents

Background

Combination therapy is essential for functional repairs of the spinal cord. Rehabilitative therapy can be considered as the key for reorganizing the nervous system after spinal cord regeneration therapy. Functional electrical stimulation has been used as a neuroprosthesis in quadriplegia and can be used for providing rehabilitative therapy to tap the capability for central nervous system reorganization after spinal cord regeneration therapy.

Objective

To develop a less invasive muscular electrical stimulation model capable of being combined with spinal cord regeneration therapy especially for motor therapy in the acute stage after spinal cord injury.

Methods

The tibialis anterior and gastrocnemius motor points were identified in intact anesthetized adult female Fischer rats, and stimulation needle electrodes were percutaneously inserted into these points. Threshold currents for visual twitches were obtained upon stimulation using pulses of 75 or 8 kHz for 200 ms. Biphasic pulse widths of 20, 40, 80, 100, 300, and 500 µs per phase were used to determine strength–duration curves. Using these parameters and previously obtained locomotor electromyogram data, stimulations were performed on bilateral joint muscle pairs to produce reciprocal flexion/extension movements of the ankle for 15 minutes while three-dimensional joint kinematics were assessed.

Results

Rhythmic muscular electrical stimulation with needle electrodes was successfully done, but decreased range of motion (ROM) over time. High-frequency and high-amplitude stimulation was also shown to be effective in alleviating decreases in ROM due to muscle fatigue.

Conclusions

This model will be useful for investigating the ability of rhythmic muscular electrical stimulation therapy to promote motor recovery, in addition to the efficacy of combining treatments with spinal cord regeneration therapy after spinal cord injuries.     

Correlation of functional outcome and X-ray findings after Perthes disease

Purpose

The purpose of this study was to evaluate the functional impairments during gait after Legg-Calvé-Perthes Disease (LCPD) and to correlate these data with the clinical and radiographic outcome.

Methods

In 13 individuals with LCPD in recovery or final stage (mean age 9.5 ± 3.5 years) with unilateral hip involvement the clinical result was graded according to Tönnis and the radiographic outcome according to Heyman and Herndon; the functional impairment during gait was compared to a group of healthy children (n = 30, mean age 8.1 ± 1.2 years). All children underwent computerised three-dimensional gait analysis.

Results

The standard physical examination resulted in 69.2% normal range of movement according to Tönnis, but overall analysis of gait revealed that only 30.7% had a normal gait pattern. All children with an excellent or good radiographic (n = 6) outcome walked normally or showed minor deviations.

Conclusions

The results of the standard clinical examination do not reflect the function of the hip joint during gait. Additional information is revealed from gait analysis and should be part of outcome studies in LCPD.     

Efficacy of cranial electrotherapy stimulation for neuropathic pain following spinal cord injury: a multi-site randomized controlled trial with a secondary 6-month open-label phase

Background

Chronic pain is a significant problem for many individuals following spinal cord injury (SCI). Unfortunately, SCI-related neuropathic pain has proven to be largely refractory to analgesic medications and other available treatments. Cranial electrotherapy stimulation (CES) has been effective in managing some types of pain. It involves the application of a small amount of current through the head via ear clip electrodes.

Objective

Explore the effectiveness of CES for neuropathic pain in persons with SCI and chronic pain.

Study design

Multi-site, double-blind, sham-controlled study.

Participants

Adults with SCI and chronic neuropathic pain at or below the level of injury were randomized to receive active or sham CES.

Intervention

Application of active CES or sham CES 1 hour daily for 21 days. Six-month open-label phase to assess ‘as-needed’ CES use.

Outcome measures

Change in pre- to post-session pain ratings as well as change in pain intensity, pain interference, pain quality, pain beliefs and coping strategies, general physical and mental health status, depressive symptomatology, perceived stress, and anxiety pre- to post-treatment.

Results

The active group reported a significantly greater average decrease in pain during daily treatments than the sham group (Kruskal–Wallis chi-square = 4.70, P < 0.05). During the 21-day trial, there was a significant group × time interaction for only one outcome variable; the active group showed larger pre- to post-treatment decreases in pain interference than the sham group did (F = 8.50, P < 0.01, d = 0.59).

Conclusions

On average, CES appears to have provided a small but statistically significant improvement in pain intensity and pain interference with few troublesome side effects. Individual results varied from no pain relief to a great deal of relief.     

Muscle spasticity associated with reduced whole-leg perfusion in persons with spinal cord injury

Objective

To determine the association between peripheral blood flow and spasticity in individuals with spinal cord injury (SCI).

Design

A cross-sectional study with measurements of muscle spasticity and whole-limb blood flow in individuals with SCI.

Setting

University of Texas at Austin and Brain & Spine Recovery Center, Austin, TX, USA.

Participants

Eighteen individuals (14 males and 4 females) with SCI were classified into high (N = 7), low (N = 6), and no (N = 5) spasticity groups according to the spasticity levels determined by the modified Ashworth scale scores.

Interventions

Whole-limb blood flow was measured in the femoral and brachial arteries using Doppler ultrasound and was normalized to lean limb mass obtained with dual-energy X-ray absorptiometry.

Outcome measures

Limb blood flow and muscle spasticity.

Results

Age, time post-SCI, and the American Spinal Injury Association impairment scale motor and sensory scores were not different among groups with different muscle spasticity. Femoral artery blood flow normalized to lean leg mass was different (P = 0.001) across the three spasticity groups (high 78.9 ± 16.7, low 98.3 ± 39.8, no 142.5 ± 24.3 ml/minute/kg). Total leg muscle spasticity scores were significantly and negatively correlated with femoral artery blood flow (r = −0.59, P < 0.01). There was no significant difference in brachial artery blood flow among the groups.

Conclusions

Whole-leg blood flow was lower in individuals with greater spasticity scores. These results suggest that a reduction in lower-limb perfusion may play a role, at least in part, in the pathogenesis leading to muscle spasticity after SCI.     

Clinical outcome and changes in gait pattern after pilon fractures

Purpose

Axial burst fractures of the distal tibia are challenging to treat and often lead to restricted function of the lower limb. The purpose of this study was to investigate the clinical outcome and changes in gait pattern in such patients.

Methods

Thirty-five patients in a level 1 trauma centre were followed up clinically and by gait analysis. The American Orthopaedic Foot and Ankle Society (AOFAS), visual analogue scale (VAS) foot and ankle scale and Phillips scores were applied. Dynamic pedography (emed-M; Novel, Germany) with analyses of load, pressure and force-time integral were undertaken to investigate possible changes in gait pattern.

Results

Mean follow-up was 50 (19–100) months. Mean AOFAS, VAS foot and ankle and Phillips scores were 65, 63 and 55 points, respectively. There were clear correlations between fracture severity in the Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification and functional outcome in AOFAS (−0.63; p < 0.01), VAS foot and ankle scale (−0.56; p < 0.01) and Phillips (−0.64; p < 0.01) scores. There was a high correlation of 0.74 (p < 0.01) between the severity of the injury in the AO-classification and onset of post-traumatic arthrosis. Dynamic pedography revealed lesser load bearing for the total foot, medial foot, heel, first metatarsal and medial forefoot for the affected limb, and increased load bearing was seen in the lateral midfoot region.

Conclusions

Fractures of the tibial pilon lead to restricted function of the lower limb. Clinical outcome correlates with fracture severity in the AO classification, the onset of post-traumatic arthrosis and changes in gait patterns.     

A Novel Non-Invasive Adjuvant Biomechanical Treatment for Patients with Altered Rehabilitation after Total Knee Arthroplasty: Results of a Pilot Investigation

Background

Many factors contribute to suboptimal results after total knee arthroplasty (TKA) but little is known regarding the value of postsurgical rehabilitation after TKA. We examined the effects of an enhanced closed kinematic chain exercises program (AposTherapy) on gait patterns and clinical outcomes among patients with a lack of progress in their postsurgical rehabilitation.

Methods

Twenty-two patients were prospectively followed during the study. Gait spatiotemporal parameters were measured at the initial evaluation, after 15 minutes of therapy, and after 3 months of therapy. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the short form (SF) 36 health survey were completed by patients before treatment and after 3 months of treatment.

Results

The WOMAC and SF-36 scores improved significantly after 3 months of treatment. Gait velocity, single limb support, and step length of the operated leg improved significantly even after a single 15 minutes treatment. Normal gait velocity was observed in 36% of patients after 3 months of treatment.

Conclusions

A physiotherapy program that included enhanced closed kinematic chain biomechanical therapy was beneficial for patients who experienced a suboptimal rehabilitation course after TKA.     

Walking,orthoses and physical effort in a Swedish population with arthrogryposis

Purpose

Excessive movements during walking have been observed by gait analysis in children with arthrogryposis (AMC) using orthoses compared to children using only shoes. The aim of this study was to evaluate energy expenditure and functional exercise capacity in children with AMC.

Methods

Twenty-four children with AMC and 25 typically developing (TD) children underwent oxygen measurement and the 6-minute walk test (6MWT). Children were divided into AMC1 using knee–ankle–foot orthoses with locked knee joints (KAFO-LK); AMC2 KAFOs with open knee joints (KAFO-O) or ankle–foot orthoses (AFO); and AMC3 using shoes.

Results

The net non-dimensional oxygen cost (NNcost) was lower in TD (0.308) than in AMC2 (0.455, n = 10) (p = 0.002). There were no differences in the net non-dimensional consumption (NNconsumption) or normalised walking velocity. The lowest NNconsumption (0.082), NNcost (0.385) and normalised walking velocity (0.214) were found in AMC1 (n = 3), but no statistical calculation was performed. In the 6MWT, both AMC2 (402.7, n = 11) and AMC3 (476.8, n = 10) walked shorter distances (m) than TD (565.1) (p < 0.001 and p = 0.043, respectively). AMC2 (0.435) had lower normalised walking velocity than TD (0.564) (p < 0.001).

Conclusions

Children with AMC using open KAFOs or AFOs (AMC2) had higher energy effort represented by significantly higher NNcost than TD, whereas AMC children requiring only shoes (AMC3) did not differ significantly from TD. To maintain the NNconsumption at an acceptable level, children using locked KAFOs (AMC1) slowed down their walking velocity. Compared to TD, the exercise capacity was lower in children with AMC using open KAFOs or AFOs and shoes, represented by lower walking velocity and shorter distance walked during the 6MWT.     

Assessment of changes in gait parameters and vertical ground reaction forces after total hip arthroplasty

The principal objectives of arthroplasty are relief of pain and enhancement of range of motion. Currently, postoperative pain and functional capacity are assessed largely on the basis of subjective evaluation scores. Because of the lack of control inherent in this method it is often difficult to interpret data presented by different observers in the critical evaluation of surgical method, new components and modes of rehabilitation. Gait analysis is a rapid, simple and reliable method to assess functional outcome. This study was undertaken in an effort to evaluate the gait characteristics of patients who underwent arthroplasty, using an Ultraflex gait analyzer.

Materials and Methods:

The study was based on the assessment of gait and weight-bearing pattern of both hips in patients who underwent total hip replacement and its comparison with an age and sex-matched control group. Twenty subjects of total arthroplasty group having unilateral involvement, operated by posterior approach at our institution with a minimum six-month postoperative period were selected. Control group was age and sex-matched, randomly selected from the general population. Gait analysis was done using Ultraflex gait analyzer. Gait parameters and vertical ground reaction forces assessment was done by measuring the gait cycle properties, step time parameters and VGRF variables. Data of affected limb was compared with unaffected limb as well as control group to assess the weight-bearing pattern. Statistical analysis was done by‘t’ test.

Results:

Frequency is reduced and gait cycle duration increased in total arthroplasty group as compared with control. Step time parameters including Step time, Stance time and Single support time are significantly reduced (P value <.05) while Double support time and Single swing time are significantly increased (P value <.05) in the THR group. Forces over each sensor are increased more on the unaffected limb of the THR group as compared to the control group. Vertical ground reaction force variables are also altered.

Conclusion:

Significant changes (P value <.05) in gait parameters and vertical ground reaction forces show that gait pattern is not normalized after THR and weight-bearing is not equally shared by both hips. Patient walks with residual antalgic gait even after surgery, which results in abnormal loading around hip joints and the integrity of the prosthesis fixation could be compromised.     

Do changes in torsional magnetic resonance imaging reflect improvement in gait after femoral derotation osteotomy in patients with cerebral palsy?

Purpose

Femoral derotation osteotomy (FDO) is commonly used to correct internal rotation gait (IRG) in spastic diplegia. The purpose of this study was to investigate whether the extent of intraoperative derotation is reflected in changes in static (clinical ROM and anteversion angle measured on torsional MRI) and dynamic parameters (transverse plane kinematics in three-dimensional gait analysis) after FDO in children with spastic diplegia.

Methods

In a prospective study, 30 children with spastic diplegia and IRG were treated with FDO as part of a multilevel surgery and were examined pre- and postoperatively clinically, by three-dimensional gait analysis and by torsional MRI according to a standardised protocol.

Results

A correlation (r = 0.317, p = 0.015) between the extent of intraoperative derotation and mean hip rotation in stance as well as the anteversion angle measured on torsional MRI (r = 0.454, p < 0.001) was found. However, no significant correlation was observed between anteversion angle (tMRI) and mean hip rotation in stance, either before or after FDO.

Conclusions

Significant improvements were found in IRG after FDO, confirming the results of previous studies. There was no correlation between the anteversion measured on MRI and the mean hip rotation in stance in 3D gait analysis before or after FDO. Thus, the data suggest that if the intraoperative extent of derotation is determined only by the anteversion angle, the result will not be better after FDO. It might only help to avoid retroversion and indicate the maximum amount of femoral derotation. In this study the extent of the intraoperative derotation was orientated at the preoperative midpoint of rotation. Based on the small, but significant correlation between the clinical midpoint and the mean hip rotation in stance in the gait analysis, determination of the intraoperative extent of derotation according to the mean hip rotation in stance seems to give the best results.     

Body composition modifications in people with chronic spinal cord injury after supervised physical activity

Background

Quantification of body composition variables is important for planning of better activities in relation to individuals with spinal cord injury (SCI).

Objectives

(1) To evaluate changes in body composition in patients with SCI after a supervised physical activity process; (2) To correlate total body fat with time since injury.

Design

Pre-post intervention.

Setting

Sarah Rehabilitation Hospital Network, Brazil.

Participants

Fifty-three men with SCI aged 18–52 years with duration of injury >3 years.

Interventions

The subjects were divided into three groups: tetraplegia (TT) (C5–C8), high paraplegia (HP) (T1–T6), and low paraplegia (LP) (T7–L2). Body composition was estimated in the first and last weeks of hospitalization.

Outcome measures

Body weight (kg), skinfolds sum (mm), absolute (kg), and relative (%) fat and lean body mass.

Results

Body weight increased in TT and decreased in HP (0.8 kg, 95%CI 0.1–1.5; and −1.0 kg, 95%CI −2.0 to 0.0, respectively; P < 0.05). Skinfolds sum decreased only in HP (−13.1 mm, 95%CI −20.7 to −5.5; P < 0.05). Absolute and relative body fat decreased significantly in the paraplegia groups. Lean body mass (LBM) percentage increased significantly in the paraplegia groups. Absolute LBM increased in TT and LP (0.8 kg, 95%CI 0.3–1.3; and 1.3 kg, 95%CI 0.8 to 1.8, respectively; P < 0.05). There was no correlation between time since injury and skinfolds sum for the three groups (P < 0.05).

Conclusion

TT, HP, and LP demonstrated favorable changes in body composition after 29 days of supervised physical activity. However, these changes were different in direction and magnitude.