Cleveland T. Barnett

Kinematic gait adaptations in unilateral transtibial amputees during rehabilitation.

Introduction: Physiotherapists routinely prescribe the use of two different early walking aids (EWAs) to individuals who have recently undergone unilateral transtibial amputation. No research to date has investigated the kinematic gait patterns of transtibial amputees walking with an EWA during early rehabilitation. The aim of the current RCT study was to compare gait patterns when walking with two different EWAs and whether either EWA provided patients with greater gait benefits. Methods: Patients were randomly assigned into one of two EWA groups, one group using the Amputee Mobility Aid and another using the Pneumatic Post-Amputation Aid, prior to receiving their functional prosthesis. A 3D motion capture system recorded kinematic data from their first steps up to discharge from rehabilitation. Results: Walking velocity increased significantly (p < 0.01) during rehabilitation. Control of the prosthetic knee improved during rehabilitation in both groups. A lack of conclusive differences between EWAs was noted at discharge from rehabilitation. Discussion: Both groups displayed changes in gait patterns in different gait measures during rehabilitation. However, these changes were not the same for both groups. Gait adaptations occurred soon after walking with a functional prosthesis. Conclusion: The results from this study would suggest that neither EWA was more beneficial for gait retraining during rehabilitation.

Postural responses during volitional and perturbed dynamic balance tasks in new lower limb amputees: A longitudinal study

This study examined the adaptation of postural responses in transtibial amputees during both perturbed and volitional dynamic balance tasks during a five-month period following discharge from inpatient rehabilitation. Seven unilateral transtibial amputees performed the sensory organisation test (SOT) and the limits of stability (LOS) test protocols on the NeuroCom Equitest(®) at one, three and six months post-discharge from in-patient rehabilitation. Overall balance ability improved significantly (p=0.01) following discharge as did utilisation of somatosensory input (p=0.01), with hip strategy use decreasing. Reaction time and movement velocity did not change significantly in the majority of target directions for the LOS test. However, endpoint COG excursion and directional control were significantly increased in a number of directions (p≤0.05). Although balance ability improved following discharge from rehabilitation, participants were heavily reliant upon vision in order to maintain balance. Following discharge from rehabilitation, amputees were seemingly able to increase the spatial and accuracy aspects of volitional exploration of their LOS. However, temporal aspects did not display any adaptation, suggesting a trade-off between these aspects of postural control. Further practice of performing volitional postural movements under increasing time pressure, for example using low-cost gaming tools, may improve balance ability and postural control.

Exercise interventions for weight management during pregnancy and up to 1 year postpartum among normal weight, overweight and obese women: a systematic review and meta-analysis

Background The prevalence of excessive gestation weight gain, extended postpartum weight retention and pregravid obese women is increasing and is associated with numerous adverse health outcomes. Objective To review the evidence from studies employing exercise-only interventions for weight management among pregnant and postpartum women. Search strategy Ten databases were searched for randomised controlled trials conducted during pregnancy or within the 12 months following childbirth and published between 1990 and 2013. Selection criteria There were no restrictions to the type, frequency, duration or intensity of exercise intervention. Interventions not specifically designed to target weight were excluded. The outcomes were a change in body weight (kg) or body mass index (BMI; kg/m2). Data collection and analysis All data were continuous and were reported as weighted mean differences (WMD), with 95% CIs. Data were analysed with a fixed-effect model and heterogeneity was determined using the I2 statistic. Results Five studies were included in this review. Exercise significantly reduced gestational weight gain (WMD=−2.22 kg, CI −3.14 to −1.3, p≤0.00001) and had no significant effect on postpartum weight loss (WMD=−1.74 kg, CI −3.59 to 0.10, p=0.06) or BMI during pregnancy (WMD=−2.8 kg/m2, CI −5.60 to 0.00, p=0.05) or postpartum (WMD=−0.54 kg/m2, CI −1.17 to 0.08, p=0.09). Conclusions There is currently limited evidence to suggest that exercise can be used to limit maternal gestational weight gain.

Manipulating walking path configuration influences gait variability and six-minute walk test outcomes in older and younger adults.

This study determined whether manipulations to walking path configuration influenced six-minute walk test (6MWT) outcomes and assessed how gait variability changes over the duration of the 6MWT in different walking path configurations. Healthy older (ODR) and younger (YNG) (n=24) adults completed familiarisation trials and five randomly ordered experimental trials of the 6MWT with walking configurations of; 5, 10 and 15m straight lines, a 6m by 3m rectangle (RECT), and a figure of eight (FIG8). Six-minute walk distance (6MWD) and walking speed (m.s(-1)) were recorded for all trials and the stride count recorded for experimental trials. Reflective markers were attached to the sacrum and feet with kinematic data recorded at 100 Hz by a nine-camera motion capture system for 5m, 15m and FIG8 trials, in order to calculate variability in stride and step length, stride width, stride and step time and double limb support time. Walking speeds and 6MWD were greatest in the 15m and FIG8 experimental trials in both groups (p<0.01). Step length and stride width variability were consistent over the 6MWT duration but greater in the 5m trial vs. the 15m and FIG8 trials (p<0.05). Stride and step time and double limb support time variability all reduced between 10 and 30 strides (p<0.01). Stride and step time variability were greater in the 5m vs. 15m and FIG8 trials (p<0.01). Increasing uninterrupted gait and walking path length results in improved 6MWT outcomes and decreased gait variability in older and younger adults.

Which prosthetic foot to prescribe

Introduction Clinicians typically use findings from cohort studies to objectively inform judgments regarding the potential (dis)advantages of prescribing a new prosthetic device. However, before finalizing prescription, a clinician will typically ask a patient to “try out” a change of prosthetic device while the patient is at the clinic. Observed differences in gait when using the new device should be the result of the devices mechanical function but could also conceivably be a result of patient-related factors, which can change from day to day and can thus make device comparisons unreliable. To determine whether a devices mechanical function consistently has a more meaningful impact on gait than patient-related factors, the present study undertook quantitative gait analyses of an individual with a transtibial amputation walking using two different foot-ankle devices on two occasions over a year apart. If the observed differences present between devices, established using quantitative gait analysis, were in the same direction and of similar magnitude on each of the two occasions, this would indicate that device-related factors were more important than patient-related factors. Materials and Methods One adult man with a unilateral transtibial amputation completed repeated walking trials using two different prosthetic foot devices on two separate occasions, 14 months apart. Walking speed and sagittal plane joint kinematics and kinetics for both limbs were assessed on each occasion. Clinically meaningful differences in these biomechanical outcome variables were defined as those with an effect size difference (d) between prosthetic conditions of at least 0.4 (i.e., medium effect size). Results Eight variables, namely, walking speed, prosthetic ankle peak plantarflexion and dorsiflexion, and peak positive power and residual knee loading response flexion, peak stance-phase extension and flexion moments, and peak negative power, displayed clinically meaningful differences (d > 0.4) between foot devices during the first session. All eight of these showed similar effect size differences during the second session despite the participant being heavier and older. Conclusions Findings suggest that a prosthetic devices mechanical function consistently has a more meaningful impact on gait than patient-related factors do. These findings support the current clinical practice of making decisions regarding prosthetic prescription for an individual based on a single-session evaluation of his/her gait using two different devices. However, to confirm this conclusion, a case series using the same approach as the present study could be undertaken.

Development of a limits of stability protocol for use in transtibial prosthesis users: Learning effects and reliability of outcome variables

The aims of this study were to empirically quantify reliability and learning effects of a Limits of Stability protocol for transtibial prosthesis users. Outcome variables from center of pressure and center of mass were tested on: 1) multiple test repetitions within a single test occasion; and 2) between multiple test occasions. Trantibial prosthesis users (n=7) and matched controls (n=7) executed five trials of the Limits of Stability protocol on two occasions per day, on two consecutive days. Inter-trial learning effects and reliability of outcomes extracted via center of mass and center of pressure were evaluated utilizing standard biomechanics laboratory equipment. Reliability was good to excellent except the reaction time variable which was poor (Pooled 95%CI of ICC=0.248-0.484). An inter-trial learning effect was present in directional control for prosthesis users when the first trial was included in analysis (center of mass: 95%CI of r=0.065-0.239; center of pressure: 95%CI of r=0.076-0.249). The use of standard biomechanics lab equipment can produce reliable results for the Limits of Stability protocol. Researchers should be aware of low reliability of reaction time variable in the protocol assessed and should execute at least one practice trial prior to that which is used in subsequent analysis.

Does an inverted pendulum model accurately represent the gait of individuals with unilateral transfemoral amputation while walking over level ground

Background: An inverted pendulum model represents the mechanical function of able-bodied individuals walking accurately, with centre of mass height and forward velocity data plotting as sinusoidal curves, 180° out of phase. Objectives: This study investigated whether the inverted pendulum model represented level gait in individuals with a unilateral transfemoral amputation. Study Design: Controlled trial. Methods: Kinematic and kinetic data from 10 individuals with unilateral transfemoral amputation and 15 able-bodied participants were recorded during level walking. Results: During level walking, the inverted pendulum model described able-bodied gait well throughout the gait cycle, with median relative time shifts between centre of mass height and velocity maxima and minima between 1.2% and 1.8% of gait cycle. In the group with unilateral transfemoral amputation, the relative time shift was significantly increased during the prosthetic-limb initial double-limb support phase by 6.3%. Conclusion: The gait of individuals with unilateral transfemoral amputation shows deviation from a synchronous inverted pendulum model during prosthetic-limb stance. The reported divergence may help explain such individuals’ increased metabolic cost of gait. Temporal divergence of inverted pendulum behaviour could potentially be utilised as a tool to assess the efficacy of prosthetic device prescription. Clinical relevance The size of the relative time shifts between centre of mass height and velocity maxima and minima could potentially be used as a tool to quantify the efficacy of innovative prosthetic device design features aimed at reducing the metabolic cost of walking and improving gait efficiency in individuals with amputation.

Joint moments during downhill and uphill walking of a person with transfemoral amputation with a hydraulic articulating and a rigid prosthetic ankle—a case study

Introduction Functional characteristics of prosthetic ankle design may facilitate sloped walking for individuals with transfemoral (TF) amputation. The aim of the current case study was to analyze the effects of a rigid versus a hydraulically articulating ankle component on the biological joint moments of an individual with TF amputation during downhill, uphill, and level walking. Materials and Methods The gait of one individual with unilateral TF amputation, using the same prosthetic foot with rigid and hydraulic ankle components, was analyzed and compared with a control group of 18 able-bodied participants. Kinematic and kinetic data were recorded at self-selected walking speed on a sloped ramp with inclinations of −12°, −4° (downhill), 0° (level), +4°, and +12° (uphill). Results The slope influenced lower-limb joint moments similarly in both the able-bodied participants and the participant with unilateral TF amputation. The effect of altering ankle movement through exchanging prosthetic ankle componentry was most acutely seen at the hip joint of the residual limb. The use of a hydraulic ankle joint component resulted in decreased mean hip joint extension and flexion moments of up to 92% and 48%, respectively, in the residual limb when compared with the use of the rigid ankle joint component. Conclusions During sloped walking, the use of a hydraulically articulating versus rigid ankle joint component reduced the joint moments observed at the hip joint of the residual limb in an individual with unilateral TF amputation. This indicates a benefit for persons with TF amputation as the increased ankle function reduces the moment producing requirements of the hip joint, which may result in decreased energy consumption and subsequently a more efficient gait.

Do predictive relationships exist between postural control and falls efficacy in unilateral transtibial prosthesis users

OBJECTIVE To assess whether variables from a postural control test relate to and predict falls efficacy in prosthesis users. DESIGN Twelve-month within- and between-participants repeated measures design. Participants performed the limits of stability (LOS) test protocol at study baseline and at 6-month follow-up. Participants also completed the Falls Efficacy Scale-International (FES-I) questionnaire, reflecting the fear of falling, and reported the number of falls monthly between study baseline and 6-month follow-up, and additionally at 9- and 12-month follow-ups. SETTING University biomechanics laboratories. PARTICIPANTS Participants (N=24) included a group of active unilateral transtibial prosthesis users of primarily traumatic etiology (n=12) with at least 1 year of prosthetic experience and age- and sex-matched control participants (n=12). INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Postural control variables derived from center of pressure data obtained during the LOS test, which was performed on and reported by the Neurocom Pro Balance Master, namely reaction time, movement velocity (MVL), endpoint excursion (EPE), maximum excursion (MXE), and directional control (DCL). Number of falls and total FES-I scores. RESULTS During the study period, the prosthesis users group had higher FES-I scores (U=33.5, P=.02), but experienced a similar number of falls, compared to the control group. Increased FES-I scores were associated with decreased EPE (r= -0.73, P=.02), MXE (r= -0.83, P<.01) and MVL (r= -0.7, P=.03) in the prosthesis users group, and DCL (r= -0.82, P<.01) in the control group, all in the backward direction. CONCLUSIONS Study baseline measures of postural control, in the backward direction only, are related to and potentially predictive of subsequent 6-month FES-I scores in relatively mobile and experienced prosthesis users.

Does postural control predict falling and the fear of falling in lower limb amputees

This is the dataset linked to: Tang, Jing et al (2015) Use of gait lab 3D motion capture for dynamic assessment of amputee socket interface biomechanics – a preliminary study. Prosthetics and Orthotics International, 39, (1), supplement 2-608, 257. doi:10.1177/0309364615591101).Background: Sierra Leone is a low income country in West Africa that has a history of conflict. Sierra Leone have signed and ratified the Convention of Rights of Persons with Disabilities. Aim: To evaluate persons with disability that use prosthetic and orthotic assistive devices access to human rights. The addressed areas were; right to health, right to a standard of living adequate for health, right to vote, right to marry and found a family, right to education, right to work and. A further aim was to compare groups of participants regarding gender, area of residence, income and type and level of device. Methods: Questionnaires were used to collect self-reported data from 139 prosthetic and orthotic users in Sierra Leone. Results: About half of the patient considered their overall physical health as good or very good. Thirty-seven percent of the participants said their mental health is bad or very bad. The majority said they did not have access to medical care and the most common reason given was that they could not afford doctors fee. The orthotic users reported they required medical care outside home more often than the prosthetic users. About half of the participants could not access afford medication when they needed it. About half of the participants had regularly access to safe drinking water and only 10% had the possibility to eat three times a day. The majority had a reasonably or adequate house to live. Half of the participants were married and 70% had children. Almost all reported that they could vote if they wanted. About half were working but often self-employed with small business. Sixty percent could read and write. Discussion & Conclusion: There was still a need for significant progress in increased access to medical care and medication when needed for persons with lower limb physical disability in Sierra Leone. Increased access to food and clean water to facilitate an acceptable standard of living adequate for health were also necessary in order to strive towards implementing the rights to health for persons with disability.Elevated skin temperature at the body/device interface of lower-limb prostheses is one of the major factors that affect tissue health [1]. The heat dissipation in prosthetic sockets is greatly influenced by the thermal conductive properties of the hard socket and liner material employed. This leads to a hypothesis that if the thermal properties of the socket & liner materials are known then the in-socket skin temperature could be accurately predicted by measuring between the socket and interface liner, rather than at the more technically challenging skin interface.Book 7th Annual International Conference on Business, Law & Economics 4-7 May 2020, Athens, Greece Edited by Gregory T. Papanikos THE ATHENS INSTITUTE FOR EDUCATION AND RESEARCH