Changes in activities-specific balance confidence of active unilateral transtibial prosthesis users after provision of a self-aligning ankle foot.

BACKGROUND: Self-aligning ankle feet have an increased range of motion and are marketed to improve compliance over uneven terrain and increase function and balance; however, much of the existing literature focuses on the biomechanical aspect of these prostheses as opposed to patient-reported measures. OBJECTIVE: To compare activities-specific balance confidence (ABC), health-related quality of life (HR-QoL), perceived mobility, gait speed, and step length before and after provision of a self-aligning ankle foot in the active unilateral transtibial prosthesis user. STUDY DESIGN: Retrospective analysis of prospectively collected data. METHODS: Patient-reported and functional measures were captured for 85 users who were provided with a self-aligning ankle foot. Measures were recorded immediately before self-aligning ankle foot provision and again at 6 months afterward. The primary outcome was the ABC Score, along with the following secondary measures; HR-QoL using EQ-5D-5L Health Index Prosthetic Limb User Survey of Mobility and 10-meter timed walk test. RESULTS: The median age of the cohort was 55.2 years old and 71% were males, with the majority having their transtibial amputation due to trauma. There was a statistically significant improvement in ABC from 76 to 86% (p < 0.001) with a medium effect size. There was no statistically significant improvement in HR-QoL (p = 0.051), Prosthetic Limb User Survey of Mobility (p = 0.043), time taken to walk 10 m (p = 0.15) and step length (p = 0.003). CONCLUSIONS: Self aligning ankle feet increased ABC and step length with no detrimental effect on HR-QoL, perceived mobility or walking speed in those with a unilateral trans-tibial amputation.

Absent loading response knee flexion: The impact on gait kinetics and centre of mass motion in individuals with unilateral transfemoral amputation, and the effect of microprocessor controlled knee provision.

BACKGROUND: Individuals with unilateral transfemoral amputation walk with increased levels of asymmetry, and this is associated with reduced gait efficiency, back pain and overuse of the intact limb. This study investigated the effect of walking with a unilateral absence of loading response knee flexion on the symmetry of anterior-posterior kinetics and centre of mass accelerations. METHODS: A retrospective cohort study design was used, assessing three-dimensional gait data from individuals with unilateral transfemoral amputation (n = 56). The anterior-posterior gait variables analysed included; peak ground reaction forces, impulse, centre of mass acceleration, as well as rate of vertical ground reaction force increase in early stance. With respect to these variables, this study assessed the symmetry between intact and prosthetic limbs, compared intact limbs against a healthy unimpaired control group, and evaluated effect on symmetry of microprocessor controlled knee provision. FINDINGS: Significant between-limb asymmetries were found between intact and prosthetic limbs across all variables (p < 0.0001). Intact limbs showed excessive loading when compared with control group limbs after speed normalisation across all variables (p < 0.0001). No improvement in kinetic symmetry following microprocessor controlled knee provision was found. INTERPRETATION: The gait asymmetries for individuals with transfemoral amputation identified in this study suggest that more should be done by developers to address the resultant overloading of the intact limb, as this is thought to have negative long-term effects. The provision of microprocessor controlled knees did not appear to improve the asymmetries faced by individuals with transfemoral amputation, and clinicians should be aware of this when managing patient expectations.

Comparison of patient-reported and functional outcomes after transition from traditional upper limb prosthetics to multiarticulating hands in the user with a unilateral transradial amputation.

BACKGROUND: Multiarticulating hands (MAHs) have been commercially available for over 15 years. Despite this, their cost remains significantly higher than traditional electric hands, and they are not routinely available in many countries. The Scottish Specialist Prosthetic Service within the National Health Service has been prescribing MAHs since 2014. However, the benefits of MAHs provided in clinical settings are not well known. OBJECTIVES: This study aimed to compare patient-reported and functional measures in unilateral transradial prosthetic users transitioning from a body-powered or traditional myoelectric prosthesis to a MAH. STUDY DESIGN: This was a retrospective cohort analysis of individuals with a unilateral transradial amputation provided with a MAH. METHODS: Of 38 users provided with MAHs, 20 had complete data sets of patient-reported and functional measures before and 6 months after provision. These included Disabilities of the Arm, Shoulder, and Hand; Southampton Hand Assessment Procedure Index of Function; health-related quality of life (EQ-5D-5L Health Index); Trinity Amputation and Prosthesis Experience Scales satisfaction; and Box and Block Test. RESULTS: The mean age was 44 years (SD 16) (n = 20), and 75% were male. There were an 8-unit mean reduction in the Disabilities of the Arm, Shoulder, and Hand ( P = .01) and a 9.5-unit improvement in the Southampton Hand Assessment Procedure IOF ( P = .007) at 6 months after provision. Health-related quality of life did not change ( P = .581). Users reported a four-point improvement in their Trinity Amputation and Prosthesis Experience Scales ( P = .004) and transferred 3.3 blocks more completing the Box and Block Test ( P = .001). CONCLUSIONS: The evidence clearly supports continued provision of MAHs to this group of moderate users: the more function the user achieves, the less of a disability they perceive to have.

Functional quadriceps reconstruction: 3D gait analysis, EMG and environmental simulator outcomes.

OBJECT: Limited objective evidence exists on the benefits of functional muscle transfers following quadriceps resection in sarcoma. In particular, no studies have compared patients with functional transfers to those without. In this study, objective and subjective assessments were performed with 3D Gait Analysis, Environmental Simulator, Electromyography (EMG) and Patient-Reported Outcomes. METHODS: Thirty-four patients at the Scottish Sarcoma Network Glasgow Centre/ Canniesburn Plastic Surgery Unit underwent quadriceps resection for sarcoma between 2009 - 2019, including 24 patients with functional reconstruction and 10 without. Both groups were equivalent for the extent of quadriceps resection (2.58 versus 2.85 components, p=0.47). Primary outcome measure was 3D Gait Analysis and Gait Profile Score (GPS), and secondary outcome was the Toronto Extremity Salvage Score (TESS) score. Ancillary analyses included environmental simulation with the Motek CAREN system and EMG of transferred muscles. RESULTS: Outcomes measures were better in functional reconstruction patients when compared to those without - the GPS score was 8.04 versus 10.2 (p=0.0019), and the TESS score was 81.85 versus 71.17 (p=0.028). Environmental simulator tasks found that functional reconstruction patients could complete activities of daily living including shopping and collision avoidance tasks, without significantly slowing their walking speed. Patients without a functional reconstruction could not complete weighted shopping tasks. EMG showed that transferred hamstrings co-activated with the ipsilateral rectus femoris during the gait cycle. CONCLUSIONS: These are the first objective data demonstrating the superiority of muscle transfers for functional restoration in quadriceps resection versus patients without functional transfers. Critically, these also provide answers to patient-oriented questions relating to the recovery of function and activities of daily living.

Minimal clinically important difference in walking velocity, gait profile score and two minute walk test for individuals with lower limb amputation.

BACKGROUND: Individuals with lower limb amputation are routinely assessed with a variety outcome measures, however there is a lack of published data to indicate minimal clinically important differences (MCID) for many of these outcome measures. Three such important gait-specific outcome measures include walking velocity, gait profile score (GPS) and the two minute walk test (2MWT). RESEARCH QUESTION: Determine the MCIDs for walking velocity, GPS and 2MWT for individuals with lower limb amputation. METHODS: Walking velocity and GPS (n = 60), and 2MWT (n = 119) data for individuals with unilateral transfemoral or knee disarticulation were identified retrospectively from a database held at the study centre. An anchor-based method was used with Medicare functional classification level (MFCL) acting as the impairment-related criterion, and a least-squares linear regression approach was used to calculate the gradient required for a change between MFCL levels. RESULTS: An increase of 0.21 m/s (95 % CI: 0.13,0.29) for walking velocity, a reduction of 1.7° (95 % CI: -2.449,-1.097) for GPS and an increase of 37.2 m (95 % CI: 28.8,45.5) for 2MWT were found to correspond to an increase in MFCL of one level. Walking velocity, GPS and 2MWT correlated with MFCL with R2 values of 0.333, 0.322 and 0.398 respectively (p < 0.00001). The authors propose that 0.21 m/s for walking velocity, 1.7° for GPS and 37.2 m for 2MWT be used as MCID values for individuals with lower limb amputation. SIGNIFICANCE: The results of this study can be used to help both researchers and clinicians to objectively evaluate if interventions for individuals with lower limb amputation are effective.

Evaluation of gait outcomes for individuals with established unilateral transfemoral amputation following the provision of microprocessor controlled knees in the context of a clinical service.

BACKGROUND: Microprocessor controlled knees (MPKs) have been shown to improve gait outcomes for individuals with unilateral transfemoral amputation (TFA); however, previous studies have limitations, which may affect their applicability. OBJECTIVES: To compare gait outcomes between non-MPK and MPK conditions within a large and diverse cohort of established TFAs in the pragmatic context of an operational clinical service and to identify any demographic variables that correlate with changes in gait outcomes. STUDY DESIGN: This is a retrospective cohort study. METHODS: Full-body three-dimensional motion capture and a portable breath gas analyser were used to evaluate gait-specific outcomes both pre-MPK and 6 months post-MPK provisions in TFAs (n = 32). The primary outcome measure was gait profile score, along with the following secondary outcome measures: walking velocity, step length, step length symmetry ratio, step time symmetry ratio, vertical ground reaction force symmetry index, base of support, center of mass deviation, and oxygen cost of walking. RESULTS: Data showed statistically significant improvement in gait profile score from 11.2° ± 2.2° to 10.1° ± 2.1° (p < 0.01) between non-MPK and MPK conditions. Other outcomes which showed significant improvement were walking velocity (p < 0.01), step length (p < 0.01), vertical ground reaction force symmetry index (p < 0.01), and center of mass deviation (p < 0.05). CONCLUSIONS: MPK provision offered significant gait improvements to this cohort of TFAs in an operational clinical setting. There still remains a large gap in gait outcomes between this cohort and those of healthy unimpaired adults. Improvements in socket design, prosthetic foot design, and physiotherapy intervention could further reduce this gap.

Comparison of patient-reported and functional outcomes following transition from mechanical to microprocessor knee in the low-activity user with a unilateral transfemoral amputation.

BACKGROUND: The Scottish Specialist Prosthetics Service has provided microprocessor knees (MPKs) through the National Health Service since 2014, predominantly to high-activity transfemoral amputations (TFAs). Benefits of MPKs to the lower-activity TFA are less established in the literature. OBJECTIVES: This study aimed to compare patient-reported and functional measures in low-activity TFAs transitioning from a mechanical knee to a MPK. STUDY DESIGN: This is a retrospective cohort analysis of low-activity individuals with a unilateral TFA provided with an MPK. METHODS: Patient-reported measures were recorded in routine clinical care before and 6 months after MPK provision. These included HR-QoL (EQ-5D-5L Health Index), Activities Balance Confidence score, Prosthetic Limb User Survey of Mobility, falls frequency, use of walking aids, and Socket Comfort Score. Functional measures included the two-minute walk test (2MWT), L-test, and Amputee Mobility Predictor score, and three-dimensional gait analysis was used to generate a Gait Profile Score (GPS). The primary outcomes were HR-QoL and GPS. RESULTS: Forty-five participants fulfilled the inclusion criteria. Thirty-one had pre-MPK and post-MPK measures, of which 15 had three-dimensional gait analysis. The mean age (n = 31) was 60 years (SD 11), and 68% were male. HR-QoL and GPS did not significantly improve with MPK provision (p = 0.014 and p = 0.019); Amputee Mobility Predictor score, L-Test, 2MWT, falls, and Activities Balance Confidence score showed a significant improvement with MPK provision (p < 0.001). CONCLUSIONS: Although no statistically significant change in the primary outcomes was measured, there were sufficient data to support MPK provision in low-activity prosthetic users with participants demonstrating improvements in balance, 2MWT, falls frequency, and confidence.

A characterisation of established unilateral transfemoral amputee gait using 3D kinematics, kinetics and oxygen consumption measures.

BACKGROUND: Persons with unilateral transfemoral (UTF) amputation are known to walk with less efficiency than able-bodied individuals, therefore understanding the gait deviations that drive this inefficiency was considered to be important. RESEARCH QUESTIONS: What are the differences in gait outcomes between persons with UTF amputation and able-bodied persons? What is the prevalence of specific gait deviations within this group? METHODS: Using a cross-sectional study design, the level over ground gait of established prosthetics service users with UTF amputation using mechanical knee joints (n=60) were compared with able-bodied persons (n=10). Gait profile score, walking velocity, step length, step length symmetry ratio, step time symmetry ratio, vertical ground reaction force symmetry index, base of support, centre of mass deviation and metabolic energy expenditure were measured. All data were captured during walking on level ground at a self-selected speed. Prevalence of gait deviations for each UTF participant were assessed by inspection, using a predefined list of lower limb kinematic, upper body kinematic, ground reaction force and lower limb kinetic gait deviations. RESULTS: Statistically significant between-groups differences across all outcome measures were found, with all p-values <0.005, and effect sizes ranging from 'large' to 'huge'. The most prevalent gait deviations included: lack of prosthetic knee flexion in early stance (98%); lack of hip extension on the prosthetic side in late stance (82%): increased trunk side flexion range of motion across the gait cycle (92%); reduced anterior propulsion force on the prosthetic side in late stance (100%) and reduced prosthetic hip adduction moment in early stance (96%). SIGNIFICANCE: The results of this study indicate that the magnitude of the differences between UTF amputees and able-bodied persons, across a comprehensive range of gait measures, are such that significant research into all aspects of prosthetic rehabilitation to reduce these differences is clearly justified.

The immediate effects of fitting and tuning solid ankle-foot orthoses in early stroke rehabilitation.

BACKGROUND: Ankle-foot orthoses are known to have a generally positive effect on gait in stroke, however the specifc type of AFO and the time point at which it is provided are highly variable in the currently available literature. OBJECTIVE: The objective was to determine the immediate spatiotemporal and kinematic effect of custom-made solid ankle-foot orthoses in early stroke rehabilitation, compared to shod walking. METHODS: Five male and three female participants were recruited to the study (n = 8), with a mean age of 57 (16) years who were 3.5 (3) weeks post-stroke. Each received a custom-made solid ankle-foot orthosis to a predefined set of design criteria and tuned using heel wedges to control the shank inclination angle during shod walking. Repeated spatiotemporal and three-dimensional gait measures were taken pre- and immediately post-intervention. STUDY DESIGN: A pre-post-test experimental study. RESULTS: With the solid ankle-foot orthosis, walking velocity increased from 0.22 (0.2) to 0.36 (0.3) m/s (p < 0.05), overall average step length increased from 0.28 (0.1) to 0.37 (0.1) m (p < 0.05), cadence increased from 45 (19) to 56 (19) steps/min (p < 0.05) and step length symmetry ratio increased from 0.65 (0.2) to 0.74 (0.2) (not significant). No clear changes were observed in the joint kinematics of the hip and knee. CONCLUSION: In our small group of early stroke patients who were fitted with a solid ankle-foot orthosis, immediate significant improvements occurred in walking speed, step length and cadence, when compared to walking with shoes only. CLINICAL RELEVANCE: This study provides evidence about the immediate effects of custom solid ankle-foot orthoses on gait of early stroke survivors. Ankle-foot orthosis design specifications are fully described for replication. This study suggests that observing global segment orientation may be more useful than joint angles when fitting and tuning ankle-foot orthoses for optimal ankle-foot orthosis/footwear alignment.

Affordable clinical gait analysis: an assessment of the marker tracking accuracy of a new low-cost optical 3D motion analysis system.

BACKGROUND: 3D motion analysis represents a method of collecting objective, accurate and repeatable gait data, however the high cost of equipment inhibits its widespread use in routine clinical practice. OBJECTIVE: To determine the marker tracking accuracy of a new low-cost optical 3D motion analysis system. DESIGN: Comparative between-system study. SETTING: Clinical motion analysis laboratories. METHODS: A rigid cluster of four reflective markers was used to compare a low-cost Optitrack 3D motion analysis system against two more expensive systems (Vicon 612 and Vicon MX). Accuracy was measured by comparing the mean vector magnitudes (between each combination of markers) for each system, and reliability was measured through the coefficients of variation (CV). Gaps in the marker trajectories, which are considered undesirable, were also counted. RESULTS: In terms of accuracy, the largest disagreement between mean vector magnitudes for Optitrack and Vicon MX was 2.2%. The largest disagreement between Vicon 612 and Vicon MX was 2.1%. Regarding reliability, the mean CV was lowest in Vicon MX (0.3%) and similar in the Vicon 612 (2.5%) and Optitrack (2.3%) systems. The number of trajectory gaps for the Vicon MX, Vicon 612 and Optitrack systems were; zero, six and 11 respectively. CONCLUSIONS: The Optitrack system provides a low-cost 3D motion analysis system that can offer marker tracking accuracy and reliability which is comparable with an older and still widely used system (Vicon 612). Further development work is required before Optitrack can be used for full 3D gait analysis by physiotherapists and other health professionals.

Developing visualisation software for rehabilitation: investigating the requirements of patients, therapists and the rehabilitation process.

This article describes the ongoing process of engaging with users in the development and evaluation of prototype visualisation software, which aims to assist in the understanding and improvement of appropriate movements during rehabilitation. The value of the process is illustrated in the article with a discussion of the key findings of pre-pilot focus groups with stroke survivors and therapists. The article describes how the design of the visualisation software is being adapted to meet the emerging understanding of the needs of patients and professionals, and of the rehabilitation process.

Visualisation to enhance biomechanical tuning of ankle-foot orthoses (AFOs) in stroke: study protocol for a randomised controlled trial.

BACKGROUND: There are a number of gaps in the evidence base for the use of ankle-foot orthoses for stroke patients. Three dimensional motion analysis offers an ideal method for objectively obtaining biomechanical gait data from stroke patients, however there are a number of major barriers to its use in routine clinical practice. One significant problem is the way in which the biomechanical data generated by these systems is presented. Through the careful design of bespoke biomechanical visualisation software it may be possible to present such data in novel ways to improve clinical decision making, track progress and increase patient understanding in the context of ankle-foot orthosis tuning. METHODS: A single-blind randomised controlled trial will be used to compare the use of biomechanical visualisation software in ankle-foot orthosis tuning against standard care (tuning using observation alone). Participants (n = 70) will have experienced a recent hemiplegia (1-12 months) and will be identified by their care team as being suitable candidates for a rigid ankle-foot orthosis. The primary outcome measure will be walking velocity. Secondary outcome measures include; lower limb joint kinematics (thigh and shank global orientations) & kinetics (knee and hip flexion/extension moments, ground reaction force FZ2 peak magnitude), step length, symmetry ratio based on step length, Modified Ashworth Scale, Modified Rivermead Mobility Index and EuroQol (EQ-5D). Additional qualitative measures will also be taken from participants (patients and clinicians) at the beginning and end of their participation in the study. The main aim of the study is to determine whether or not the visualisation of biomechanical data can be used to improve the outcomes of tuning ankle-foot orthoses for stroke patients. DISCUSSION: In addition to answering the primary research question the broad range of measures that will be taken during this study are likely to contribute to a wider understanding of the impact of ankle-foot orthoses on the lives of stroke patients. TRIAL REGISTRATION NUMBER: ISRCTN: ISRCTN52126764.

A novel device for evaluating forces during the dynamic jar opening action--do older and younger adults do things differently?

Package opening tasks have been identified as some of the most challenging that individuals need to perform to access food. There is little previous study of the 3D hand loading that is required to open these products. A novel load measuring device was used to characterise torque, squeeze and compression forces during the dynamic action of jar opening for young and older adults. The current study showed that the older adults used lower squeeze forces (86.1 N vs. 95.4 N) and higher compressive forces (26.9 N vs. 25.2 N) on the jar lid than younger adults. Older adults tended to apply loading to the jar lid slower (0.038 Nm/s vs. 0.044 Nm/s) and to open the jar at a slower rate (0.84 Rad/s vs. 1.59 Rad/s) than young adults whilst using a higher proportion of their maximal grip strength (40% vs. 27%) indicating that older adults used a more cautious opening strategy. These differences suggest that a simple maximal torque test is not sufficient to characterise older adults' abilities in relation to package opening. The loading required to open packaging should be understood to ensure that packaging design is developed to be inclusive. This is the first report of realistic complex packaging opening loading presented in the literature.