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

Abstract

BackgroundThere 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.MethodsA 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.DiscussionIn 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 numberISRCTN: ISRCTN52126764

Outcome measures and motion capture systems for assessing lower limb orthosis-based interventions after stroke: a systematic review

“…The total risk of bias was determined considering the assessments of each author to make an overall quality assessment of this review. The included trials involved 387 participants at different sample sizes, ranging from 3 [22] to 70 [23] participants. The sample sizes most observed (38.89% of studies) range from 20 to 30 participants.…”

“…AFO was prescribed in 16 studies (88.9%), while only 2 studies [22,24] used the knee orthosis. The conventional AFO configuration (i.e., polymeric, non-articulated posterior leaf-spring AFO) was applied in 15 randomized trials [5,23,[33][34][35][36][37][25][26][27][28][29][30][31][32] whereas the studies [33,38] used the anterior rigid configuration. Two studies [35,37] explored a more compliant orthotic system by employing a dynamic AFO.…”

“…[24,30,34,37], stride duration [24,32,33,36,37], and symmetry index [23,24,30] were the spatiotemporal parameters most recorded. The gait velocity was identified as the primary outcome [23,24,28,30,34,36]. Only one work reported the normalization of spatial metrics, namely the step length normalized to body height [34].…”

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

“…Five males and three females (Table 1) were recruited as part of an ongoing randomised controlled trial investigating the effectiveness of using biomechanical data to fit and tune AFOs. 24 Participants in this study had to be within 1-12 months after stroke, over 16…”

“…Five males and three females (Table 1) were recruited as part of an ongoing randomised controlled trial investigating the effectiveness of using biomechanical data to fit and tune AFOs. 24 Participants in this study had to be within 1-12 months after stroke, over 16 years of age, meet the criteria for AFO referral as outlined in the NHS BPS (able to walk with assistance but had difficulty flexing knee and extending hip during gait), assessed by a participating NHS orthotist and judged suitable for a custom solid AFO. Participants had a mean age of 57 (16) years and were 3.5 (3) weeks post-stroke.…”