Johnny Collett

Exercise for multiple sclerosis: a single-blind randomized trial comparing three exercise intensities:

Background: The most effective exercise dose has yet to be established for multiple sclerosis (MS). Objective: The aim of this study was to investigate the effect of different exercise intensities in people with MS. Methods: We completed a randomized comparator study of three cycling exercise intensities, with blinded assessment, was carried out in Oxford. Sixty-one adults with MS who fulfilled inclusion criteria were randomized at entry into the study, using a computer-generated list held by an exercise professional, into either: continuous (at 45% peak power, n = 20), intermittent (30 sec on, 30 sec off at 90% peak power, n = 21) or combined (10 min intermittent at 90% peak power then 10 min continuous at 45% peak power, n = 20) exercise for 20 min twice a week for 12 weeks in a leisure facility. Groups were assessed at: baseline, halfway (6 weeks), end intervention (12 weeks) and follow-up (24 weeks). Primary outcome measure was 2 min walk. Results: Fifty-five participants were included in the analysis (n = continuous 20, intermittent 18, combined 17). No differences were found between groups. After 6 weeks, considering all participants, 2 min walk distance increased by 6.96 ± 2.56 m (95% CI: 1.81 to 12.10, effect size (es): 0.25, p < 0.01). The continuous group increased by 4.71 ± 4.24 m (95% CI: −3.80 to 13.22, es: 0.06), intermittent by 12.94 ± 4.71 m (95% CI: 3.97 to 21.92, es: 0.28) and combined by 3.22 ± 4.60 m (95% CI: −6.01 to 12.46, es: 0.04). Two minute walk did not significantly change between further assessments. Between 6 and 12 weeks there was a drop in attendance that seemed to be associated with the intermittent and combined groups; these groups also had a greater number of adverse events (leg pain during cycling most common) and dropouts (n = continuous 1, intermittent 5, combined 10). Considering all participants, 6 weeks of cycling exercise produced benefits in mobility that were maintained with further sessions. Conclusion: While no differences were found between groups, greater benefit may be associated with higher-intensity exercise, but this may be less well tolerated.CONSORT - trial registration number (ISRCTN89009719)

IMU: Inertial sensing of vertical CoM movement

The purpose of this study was to use a quaternion rotation matrix in combination with an integration approach to transform translatory accelerations of the centre of mass (CoM) from an inertial measurement unit (IMU) during walking, from the object system onto the global frame. Second, this paper utilises double integration to determine the relative change in position of the CoM from the vertical acceleration data. Five participants were tested in which an IMU, consisting of accelerometers, gyroscopes and magnetometers was attached on the lower spine estimated centre of mass. Participants were asked to walk three times through a calibrated volume at their self-selected walking speed. Synchronized data were collected by an IMU and an optical motion capture system (OMCS); both measured at 100 Hz. Accelerations of the IMU were transposed onto the global frame using a quaternion rotation matrix. Translatory acceleration, speed and relative change in position from the IMU were compared with the derived data from the OMCS. Peak acceleration in vertical axis showed no significant difference (p> or =0.05). Difference between peak and trough speed showed significant difference (p<0.05) but relative peak-trough position between the IMU and OMCS did not show any significant difference (p> or =0.05). These results indicate that quaternions, in combination with Simpsons rule integration, can be used in transforming translatory acceleration from the object frame to the global frame and therefore obtain relative change in position, thus offering a solution for using accelerometers in accurate global frame kinematic gait analyses.

Assessment of spatio-temporal gait parameters using inertial measurement units in neurological populations

Laboratory based gait analysis techniques are expensive, time consuming and require technical expertise. Inertial measurement units can directly measure temporal parameters and in combination with gait models may provide a solution to obtain spatial gait measurements within daily clinical assessments. However it is not known if a model and standard correction factor determined by Zijlstra and Hof [8] to estimate step and stride length parameters in typically developed adults (TDA) can be accurately used in neurologically impaired gaits. This research estimated the stride length over two 10 m walks at self selected walking speed in people with neurological conditions, using a previously established model and correction factor for TDA. The relation of the correction factor to walking speed was explored. We recruited TDA (n=10) and participants with Parkinsons disease (PD; n=24), muscular dystrophy (MD; n=13), motor neuron disease (MND; n=7) and stroke survivors (n=18) for the study who twice walked 10 m at a self-selected pace. Stride length correction factors, for TDA (1.25±0.01), PD (1.25±0.03), and MD (1.21±0.08) (p=0.833 and p=0.242) were the same as previously reported in TDA (Zijlstra and Hof [8]). Correction factors for stroke (1.17±0.42) and MND (1.10±0.08) were different (p<0.01 and p=0.028 respectively). However there was a high level of variability for correction factors within groups, which did not relate to walking speed. Our findings support that correction factors should be determined for each individual to estimate average step/stride length in patients suffering from a neurological condition.

Pedometer step counts in individuals with neurological conditions

Objective: To examine the accuracy of measuring step counts using a pedometer in participants with neurological conditions and healthy volunteers in relation to a manual step count tally. Setting: Oxford Centre for Enablement, Nuffield Orthopaedic Centre NHS Trust, Oxford, UK. Subjects: Healthy adults (n = 13, age: mean 29, SD = 12) and adults with neurological conditions (n=20 stroke, n=16 multiple sclerosis, n=5 muscular dystrophy, n=1 spinal cord injury, n=1 traumatic brain injury; age: mean 54, SD=13). Main measures: Individuals walked for 2 minutes at self-selected walking speeds (SSWS) wearing a pedometer. Healthy individuals were then asked to walk at slow walking speeds (SWS). Step counts were recorded manually and using a pedometer. Results: In healthy individuals there was no difference between manually measured and pedometer counts during walking (P>0.05). In adults with neurological conditions the pedometers undercounted (P = 0.003); bias (random error): 27 (111); percentage variability 30% and intraclass correlation coefficient (ICC) 0.66. In neurological adults, from regression analysis the relationship between error and walking speed was cubic, with walking speed accounting for 29% of pedometer error. Healthy individuals showed greater variability and undercounting at SWS bias (random error): 10 (31), percentage variability 8% and ICC 0.73, compared with SSWS bias (random error): —3 (13), percentage variability 3% and ICC 0.84. Conclusions: Pedometers may undercount when used for people with neurological conditions. There may be variability in pedometer accuracy but this was not strongly related to walking speed. The suitability of pedometer use for exercise monitoring should be individually determined.

Wearable accelerometry-based technology capable of assessing functional activities in neurological populations in community settings: a systematic review

BackgroundIntegrating rehabilitation services through wearable systems has the potential to accurately assess the type, intensity, duration, and quality of movement necessary for procuring key outcome measures.ObjectivesThis review aims to explore wearable accelerometry-based technology (ABT) capable of assessing mobility-related functional activities intended for rehabilitation purposes in community settings for neurological populations. In this review, we focus on the accuracy of ABT-based methods, types of outcome measures, and the implementation of ABT in non-clinical settings for rehabilitation purposes.Data sourcesCochrane, PubMed, Web of Knowledge, EMBASE, and IEEE Xplore. The search strategy covered three main areas, namely wearable technology, rehabilitation, and setting.Study selectionPotentially relevant studies were categorized as systems either evaluating methods or outcome parameters.MethodsMethodological qualities of studies were assessed by two customized checklists, depending on their categorization and rated independently by three blinded reviewers.ResultsTwelve studies involving ABT met the eligibility criteria, of which three studies were identified as having implemented ABT for rehabilitation purposes in non-clinical settings. From the twelve studies, seven studies achieved high methodological quality scores. These studies were not only capable of assessing the type, quantity, and quality measures of functional activities, but could also distinguish healthy from non-healthy subjects and/or address disease severity levels.ConclusionWhile many studies support ABT’s potential for telerehabilitation, few actually utilized it to assess mobility-related functional activities outside laboratory settings. To generate more appropriate outcome measures, there is a clear need to translate research findings and novel methods into practice.

Fast walking under cognitive-motor interference conditions in chronic stroke

Gait in stroke patients is often characterised by slower speeds, which may be exacerbated by situations that combine gait with a cognitive task, leading to difficulties with everyday activities. Interaction between cognitive task performance and gait speed may differ according to walking intensity. This study examines the effects of two cognitive tasks on gait at preferred walking pace, and at a faster pace, using dual-task methodology. 21 chronic stroke patients and 10 age-matched control subjects performed 2 single motor tasks (walking at preferred and at fast pace around a walkway), and two cognitive tasks (serial subtractions of 3s and a visual-spatial decision task) under single- and dual-task conditions (cognitive-motor interference) in a randomised order. Cognitive task score and gait speed were measured. The healthy control group showed no effects of CMI. The stroke group decreased their walking speed whilst concurrently performing serial 3s during both preferred and fast walking trials and made more mistakes in the visuo-spatial task during fast walking. There was no effect of walking on the serial 3 performance. The findings show that in stroke patients, during walking whilst concurrently counting backwards in 3s the cognitive task appeared to take priority over maintenance of walking speed. During fast walking whilst concurrently performing a visuo-spatial imagery task, they appeared to favour walking. This may indicate that people spontaneously favour one activity over the other, which has implications for gait rehabilitation.

Interventions for fatigue in Parkinson's disease: A systematic review and meta-analysis

The authors sought to review the efficacy of interventions for fatigue in Parkinsons disease. A search was conducted of PubMed, Cinahl, Psychinfo, EMBASE, and Web of Knowledge up to November 2013. Methodological quality was assessed using the PEDro scale. For meta‐analyses, studies were weighted on variance. Effect sizes were calculated with 95% confidence interval (CI); overall effect was presented by means of a Z‐score; heterogeneity was investigated using the I2. Fourteen articles (n = 1,890) investigating drugs and behavioral therapy were eligible. Ten studies demonstrated excellent, three good, and one fair methodological quality. Three articles (investigating amphetamines) were appropriate for meta‐analysis, which was performed according to scales used: Multidimensional Fatigue Inventory: mean difference, –6.13 (95%CI: –14.63‐2.37, Z = 1.41, P = 0.16; I2 = 0); Fatigue Severity Scale: mean difference, –4.00 (95%CI: –8.72‐0.72, Z = 1.66, P = 0.10; I2 = 0). Currently insufficient evidence exists to support the treatment of fatigue in PD with any drug or nondrug treatment. Further study is required.

Validity and inter-rater reliability of inertial gait measurements in Parkinson's disease: A pilot study

Walking models driven by centre of mass (CoM) data obtained from inertial measurement units (IMU) or optical motion capture systems (OMCS) can be used to objectively measure gait. However current models have only been validated within typical developed adults (TDA). The purpose of this study was to compare the projected CoM movement within Parkinsons disease (PD) measured by an IMU with data collected from an OMCS after which spatio-temporal gait measures were derived using an inverted pendulum model. The inter-rater reliability of spatio-temporal parameters was explored between expert researchers and clinicians using the IMU processed data. Participants walked 10 m with an IMU attached over their centre of mass which was simultaneously recorded by an OMCS. Data was collected on two occasions, each by an expert researcher and clinician. Ten people with PD showed no difference (p=0.13) for vertical, translatory acceleration, velocity and relative position of the projected centre of mass between IMU and OMCS data. Furthermore no difference (p=0.18) was found for the derived step time, stride length and walking speed for people with PD. Measurements of step time (p=0.299), stride length (p=0.883) and walking speed (p=0.751) did not differ between experts and clinicians. There was good inter-rater reliability for these parameters (ICC3.1=0.979, ICC3.1=0.958 and ICC3.1=0.978, respectively). The findings are encouraging and support the use of IMUs by clinicians to measure CoM movement in people with PD.

Physical activity levels in adults with intellectual disabilities: A systematic review

Despite evidence that inactivity is a major factor causing ill health in people with intellectual disabilities (pwID) there are gaps in our knowledge of their physical activity (PA). To date, there is no published systematic review of their PA levels. Therefore, we performed a systematic review from January–October 2015, comprising studies from across the globe to establish PA levels, determine how they were measured, and what factors influenced PA in adults with intellectual disabilities (awID). Five databases were searched. Studies were included if written in English, peer-reviewed, had primary research data, and measured PA levels of awID. Quality was assessed using a 19-item checklist. Meta-summary of the findings was performed and a meta-analysis of factors influencing PA using multiple regression. Fifteen studies were included consisting of 3159 awID, aged 16–81 years, 54% male and 46% female. Only 9% of participants achieved minimum PA guidelines. PA levels were measured using objective and subjective methods. ID severity, living in care, gender, and age were independently significantly correlated with the number of participants achieving PA guidelines with the strongest predictor being ID severity (Beta 0.631, p < 0.001). Findings should be in the context that most of the participants were in the mild/moderate range of ID severity and none of the studies objectively measured PA in people with profound ID. To inform measurement and intervention design for improved PA, we recommend that there is an urgent need for future PA studies in awID population to include all disability severity levels. PROSPERO registration number CRD42015016675.

Reliability of single and paired-pulse transcranial magnetic stimulation in the vastus lateralis muscle

Introduction: Transcranial magnetic stimulation (TMS) is an important tool to examine neurological pathologies, movement disorders, and central nervous system responses to exercise, fatigue, and training. The reliability has not been examined in a functional locomotor knee extensor muscle. Methods: Within‐ (n = 10) and between‐day (n = 16) reliability of single and paired‐paired pulse TMS was examined from the active vastus lateralis. Results: Motor evoked potential amplitude and cortical silent period duration showed good within‐ and between‐day reliability (intraclass correlation coefficient [ICC] ≥ 0.82). Short‐ and long‐interval intracortical inhibition (SICI and LICI, respectively) demonstrated good within‐day reliability (ICC ≥ 0.84). SICI had moderate to good between‐day reliability (ICC ≥ 0.67), but LICI was not repeatable (ICC = 0.47). Intracortical facilitation showed moderate to good within‐day reliability (ICC ≥ 0.73) but poor to moderate reliability between days (ICC ≥ 0.51). Conclusions: TMS can reliably assess cortical function in a knee extensor muscle. This may be useful to examine neurological disorders that affect locomotion. Muscle Nerve 52: 605–615, 2015