Browsing by Author "Albertus, Yumna"

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    Open Access
    A randomised control trial for the restoration of functional ability in patients post total knee arthroplasty: Eccentric versus concentric cycling ergometry
    (2018) Silal, Sandhya Prakash; Albertus, Yumna; Tam, Nicholas; Posthumus, Michael
    Introduction: While the total knee arthroplasty procedure improves joint-specific outcomes, including pain and range of movement, functional deficits post-surgery has been noted. Movement abnormalities and quadriceps weakness of the operated limb, as well as a decrease in strength on the non-operated have been widely reported. Recovery of strength and function to normal levels is also rare, thereby predisposing patients to future disability with increasing age. The purpose of this study was to determine the effects of an eight-week eccentric cycling ergometry exercise intervention versus a concentric cycling ergometry exercise intervention in total knee arthroplasty recipients three to nine months post-surgery. This study aimed to a) investigate the change in joint kinetics, kinematics and muscle activity during the phases of gait, between the eccentric and concentric groups over time and b) To determine if an eccentric cycling exercise intervention produces greater improvements in knee function when compared to concentric cycling exercise. Methods: Eighteen participants, three to nine months post total knee arthroplasty were recruited and randomly assigned to either an eccentric or concentric cycling exercise intervention group. Participants performed three exercise sessions weekly over a progressive eight-week period on the Grucox Isokinetic Ergometer. Walking gait analyses and functional outcomes, as measured by the six-minute walk test and validated knee scores (Knee Injury and Osteoarthritis Outcome Score, SF-36 Health Survey and Tegner Activity Scale) were recorded pre- and post-intervention. Results: The concentric group knee flexion range of movement increased significantly during the swing phase of gait (p=0.021) post-intervention together with a significant increase in the peak knee flexion angle during swing (p=0.038). The concentric group showed significant differences between pre and post-rehabilitation in knee flexion range of movement during the swing phase of gait (p=0.030). Significant correlations between knee joint stiffness and the quadriceps:hamstring co-activation ratio were observed in the concentric intervention group pre-intervention: during the pre-activation phase of gait between knee joint stiffness and vastus medialis / biceps femoris (r=-0.68; p=0.042) and during load acceptance phase of gait between knee joint stiffness and vastus lateralis / biceps femoris (r=0.07; p=0.036). The eccentric group recorded neuromuscular changes post-intervention with a significant decrease in the muscle activity of the biceps femoris during load acceptance phase of gait (p=0.021). The eccentric group had significantly better functional outcomes in the overall score of Knee injury and Osteoarthritis Outcome post-intervention (p=0.008) with a significant increase in function seen in the Sports and Recreation subgroup (p=0.008) and a significant increase in the level of activity as measure by the Tegner Activity Scale post-intervention (p=0.028), despite not showing any significant changes in the knee joint kinetics and kinematics. The concentric group only reported a significant increase in the overall score of the of the SF-36 Health Survey (p=0.011) with significant increases in three of the subgroups post-intervention: Bodily pains had improved (p=0.042), the role limitations due to physical heath had improved (p=0.028) and the role limitations due to emotional health had also improved (p=0.009). The concentric group also showed significant improvement in the emotional health over the intervention in comparison to the eccentric intervention group (p=0.020). Both intervention groups reported a similar significant increase in the distance covered during the six-minute walk test post-intervention (p=0.038). Conclusion: The results of this exploratory study did not find the eccentric cycling rehabilitation intervention exclusively more effective than the concentric cycling intervention in the restoration of functional ability in patients post-TKA. The eccentric intervention did however result in neuromuscular adaptations consistent with a move towards a more typical asymptomatic gait pattern and participants reported greater functional improvements on validated knee functional assessments and levels of activity scores. The concentric intervention yielded kinematic changes and participants reported improvements in their emotional and physical health post-intervention. Eccentric training and its role in early stage post-operative rehabilitation is limited. Based on the findings from this exploratory study, the benefit of eccentric training as an adjunct to rehabilitation and its role in contributing to greater improvements in the restoration of functional ability post-TKA needs to be further explored.
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    Open Access
    Critical analysis of techniques for normalising electromyographic data : from laboratory to clinical research
    (2008) Albertus, Yumna; Lambert, Mike; Derman, Wayne; Tucker, Ross; Noakes, Tim
    Measurements of muscle activity derived from surface EMG electrodes are variable due to both intrinsic and extrinsic factors. The intrinsic factors are endogenous in nature (features within the body) and include muscle fiber type, muscle fiber diameter and length, the amount of tissue between muscle and electrode, and depth and location of muscle with respect to the placement of electrodes (24). These biological factors vary between subjects and cannot be controlled. The extrinsic factors are experimental variables which are influenced by the researcher and can be controlled to some extent. Examples of extrinsic factors include the location, area, orientation, shape of electrodes and the distance between electrodes (interelectrode distance). In order to measure biological variation in the EMG signal, which is important in studies where surface EMG is used to gain understanding of physiological regulation, it is important to minimise the variation caused by these factors. This is in part achieved through the appropriate method of normalisation. The isometric maximal voluntary contraction (MVC) has been used as a standardmethod of normalisation for both static and dynamic exercises. However, researchers have recently improved the methods of normalisation by developing alternative techniques for the measurement of EMG during dynamic activities. By using the same type of movement for normalisation as during the trial, experimental errors can be reduced. The appropriate method of normalisation is defined as a method that is capable of showing repeatability, reliability (low intra-subject variation) and sensitivity to changes in EMG amplitude that is due to biological change and not the contribution of experimental factors. The aim of this thesis was to critically analyse alternative methods of EMG normalisation during dynamic exercise. The data should provide possible guidelines to researchers who are planning studies involving measurement of EMG activity during cycling, running and in clinical populations. Furthermore, the thesis aimed to illustrate that decisions regarding the most appropriate method of normalisation should be based on the study design, research question (absolute muscle activity or changes in muscle pattern) and the muscles being investigated.
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    Open Access
    Development and Validation of Experimental Protocol and Guidelines for Non-Invasive Superficial and Deep Muscle Electromyography in the Forearm
    (2018) Brijlal, Yasheen; Albertus, Yumna; de Jager, Kylie; Franz, Thomas
    The present study investigated a novel non-invasive superficial and deep surface electromyography (sdEMG) technique to detect and isolate extrinsic muscles of the hand with the aim of developing experimental guidelines to aid future studies. The sdEMG technique comprises of two or more surface electrode arrays encircling the limb under investigation set up in a monopolar EMG recording modality and a blind source separation (BSS) algorithm to decompose the recorded mixed monopolar EMG signals into their constituent components, which is proposed to reflect the underlying EMG activity of each muscle. Three experimental parameters linked to the finger movement protocol (MP) were investigated that varied the effects of timing, randomisation and movement anticipation on the ability of the sdEMG technique to detect and isolate the superficial muscles flexor digitorum superficialis (FDS) and extensor digitorum (ED), and the deep muscles extensor indicis (EI), extensor pollicis longus (EPL), flexor digitorum profundus (FDP) and flexor pollicis longus (FPL). FDS and FDP were split into FDS-Index, FDS-Ring, FDP-Index and FDP-Ring bands resulting in a total of eight muscles investigated. A standard movement protocol consisting of 12 dynamic movements was designed to target the activation of the investigated muscles during each experimental run. The Timing experiments varied the movement window duration to 3, 5 and 7 seconds using the standard MP sequence. The Randomisation experiment consisted of a randomised MP sequence. The Anticipation experiment presented participants with the current, and next movement instruction in the standard MP sequence. The developed sdEMG system implemented 64 custom-made surface electrodes arranged in three bands positioned around the distal third of the forearm. An OT Bioelettronica® EMG-USB2 256-channel biopotential amplifier was used, set up in a referenced monopolar EMG configuration. Contraction detection apparatus was built consisting of finger exoskeletons and flex sensors to record when finger movements occurred. A forearm testing platform was built to secure the participant’s forearm during experimental testing and a visual participant instruction system was developed to convey the timed movement instructions. Five healthy, right-hand dominant male participants (mean ± SD; age: 24 ± 3 years) without any history of neuromuscular diseases or disabilities were recruited for the study. Each participant completed five experimental runs of the five MP variations while the EMG and flex sensor data was recorded. Independent Component Analysis (ICA) was used as the BSS algorithm and the EMG recordings were decomposed into Independent Components (ICs) which were further processed with a windowed 250ms root mean square (RMS) smoothing filter as well as signal normalisation. The flex sensor data was used to generate synchronised literature-informed predicted EMG (pEMG) waveforms, representing the ideal EMG activation signals for each muscle. The muscle-specific pEMG waveforms were also processed with a 250ms RMS filter and signal normalisation before signal comparisons were made using Pearson’s correlation against all pICs. In each experimental run, the pIC with the highest calculated Pearson’s correlation coefficient (r) value for each pEMG waveform was initially selected as the representative IC (rIC) for that muscle. A rIC selection algorithm was also developed which reassigned pICs that were selected to represent multiple muscles to ensure each muscle was assigned a unique rIC. A case study was conducted to evaluate the effects of the investigated movement protocol parameters upon which experimental guidelines were formed. Fisher-corrected mean population correlation coefficients (ρ) and 95% confidence intervals were calculated to evaluate the effects of timing, randomisation and anticipation of movements. Using an amalgamated population of all the experiments and experimental runs combined, the eight muscles investigated were isolated with ρ values greater than 0.65 indicating moderate isolation (defined as 0.60 ≤ ρ < 0.80), with the exception FDS-Index Band which was poorly isolated (ρ < 0.60) with a ρ value of 0.59. The data did, however, show high variability in all experiments indicating that the sample population was too small and was possibly influenced by poor performing participants. The Timing, Randomisation and Anticipation experiments showed no discernible effects across all participants on the ability of the sdEMG technique to detect and isolate the deep and superficial forearm muscles investigated. The Anticipation experiment also showed that participant reaction delays on average increased steadily during each experimental run suggesting the anticipated visual cues were too complex and potentially confused participants. Concise experimental sdEMG guidelines were developed in which the sdEMG technique was found to be robust to variations of the three movement protocol parameters investigated.
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    Open Access
    Illness and injuries in athletes with visual impairment at the London 2012 Paralympic Games
    (2017) Stopforth, Louise; Derman, Wayne; Albertus, Yumna
    Background: Participation in sport by athletes with impairment has grown and evolved rapidly since the inception of the Paralympic Games. Athletes with visual impairment were first included in the Paralympic Games in 1976. Surveillance of illnesses and injuries forms the first important step in determination of the epidemiology and an understanding of the risk factors for both illness and injuries in these populations. Thus, surveillance can therefore assist medical teams in implementing prevention strategies. Few studies have evaluated the incidence of illness and injuries amongst athletes with impairment. For this reason, a novel web based injury and illness surveillance system (WEBIISS) was developed for use by the team physicians at the London 2012 Paralympic Games. To our knowledge, no study has specifically researched the epidemiology of illness and injuries in athletes with visual impairment during a major sport event such as the Paralympic Games. Objective: To determine the incidence associated with illness and injuries in athletes with visual impairment during the London 2012 Paralympic Games. We further aim to describe any differences between sports, age groups, gender and body systems affected in this cohort of athletes. Methods: This study was a retrospective analysis of a component of the large prospective cohort study on the epidemiology of injury and illness conducted over a 14-day period at the London 2012 Paralympic Games. The data from 711 of the 791 athletes with visual impairment who participated in the London 2012 Paralympic Games were analyzed. The following data sources were used: Firstly, de-identified information regarding age, gender, impairment, country code and sports code of athletes obtained from the International Paralympic Committee database. Secondly, information collected from the electronic medical data capture system (EMDCS) used at all the London Organizing Committee for the Olympic and Paralympic Games (LOCOG) medical stations; and thirdly a novel web-based injury and illness surveillance system (WEB-IISS) used by the team physicians. This is the most comprehensive reporting system used in elite athletes with impairment to date. Data were collected on a daily basis from 3 days prior to the start of the Paralympic Games (pre-competition period) until the last day of the 11-day Paralympic Games (competition period). Definitions: In order to determine the nature and extent of illnesses and injuries as well to enable uniformity in research studies evaluating the data collected during the London 2012 Paralympic Games, the following definitions were implemented: Illness was defined as 'any newly acquired illness as well as exacerbation of pre-existing illness that occurred during training or competition, and during or immediately before the London 2012 Paralympic Games'. Injury was defined as 'any newly acquired injury as well as exacerbation of pre-existing injury that occurred during training and/or competition period of the London 2012 Paralympic Games'. Incidence rate (IR) of illness or injury is the number of illnesses or injuries per 1000 athlete days. Incidence proportion (IP) of illness or injury is the proportion of athletes affected by illness or injury (n/100). Results: Incidence rate of illness (IR 11.9; 95% CI 9.0 - 15.7) was similar to incidence rate of injuries (IR 14.5; 95% CI 11.3 - 18.5) in VI athletes. The IR of illness for VI athletes (IR 11.9; 95% CI 9.0 - 15.7) compared well to that of illness for all impairment groups (IR 12.7; 95% CI 10.2 - 16.0). Furthermore, the IR of injuries for VI athletes (IR 14.5; 95% CI 11.3 -18.5) compared well to that of injuries for al impairment groups (IR 12.6; 95% CI 10.3 - 15.4). Gender and age did not affect the risk of illness or injuries in VI athletes. Furthermore, there was a higher IR of illness for swimmers with visual impairment compared to other sports, but this was not statistically significant. The IR of illness for VI athletes participating in swimming was 12.5 (95% CI 8.8 - 17.8) compared to that of VI non-swimmers, IR 11.8 (95% CI 8.9 - 15.6). Participation in athletics (track and field) was associated with a slightly higher risk for injury for athletes with VI compared to other sports, but this was not statistically significant. The IR of injury was 15.8 (95% CI 11.6 - 21.5) and the IP 22.1 (95% CI 16.3 - 30.1) for VI track and field athletes. The IR of injury was 13.0 (95% CI 9.6 - 17.4) and IP 18.1 (95% CI 13.5 - 24.3) amongst VI athletes not participating in track and field athletics. VI swimmers had a lower IR of injury (IR 4.1; 95% CI 1.8 - 9.5) than VI non-swimmers (IR 16.1; 95% CI 12.6 - 20.7) (p=0.002). There was a higher IR and IP of lower limb injuries compared to upper limb injuries in athletes with visual impairment. The IR for lower limb injuries in athletes with visual impairment was 7.7 (95% CI 5.8 - 10.3) and the IP was 10.8 (95% CI 8.1 - 14.4). The average IR of lower limb injuries for all para-athletes was 4.5 (95% CI 3.5 - 5.7). The IR for upper limb injuries in athletes with visual impairment was 3.0 (95% CI 1.9 - 4.5) and the IP was 4.1 (95% CI 2.7 - 6.3). The average IR for upper limb injuries for all para-athletes was 4.5 (95% CI 3.5 - 5.9). Conclusion: The findings of this study suggest that Paralympic athletes with VI had a similar incidence rate of illness and injury compared to other impairment groups; and IR of illness was similar to that of injuries. Risk of illness or injury was not affected by age group or gender, but rather sport specific differences were observed. Of particular interest was the fact that athletes with VI had a higher incidence rate of lower limb injuries than upper limb injuries.
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    Innovative spinal cord injury rehabilitation in the context of a middle-income country: a pilot randomised control study investigating physiological and psychological effects
    (2021) Evans, Robert William; Albertus, Yumna; West, Sacha; Derman, Wayne
    A spinal cord injury (SCI) is life-altering, resulting in neurological deficits and a multitude of secondary complications. South Africa holds one of the highest traumatic SCI incidence rates in the world, where the social need for SCI prevention and rehabilitation is immense. Robotic locomotor training (RLT) is a novel rehabilitation technique that may improve health and wellbeing after SCI. A systematic review was conducted across 27 studies and 308 participants to explore the systemic effects of RLT. This review demonstrated that RLT shows promise as a tool for improving neurological rehabilitation outcomes; providing individuals with a SCI the ability to walk safely while improving their walking performance, as well as potentially improving cardiovascular outcomes and psychosocial factors. However, the studies reviewed were non-controlled with small, heterogenous sample sizes. Further high-powered, randomised controlled trials, with homogenous samples, are required to investigate these effects. If widespread adoption of these new technologies is to occur, sound evidence demonstrating efficacy and long-term cost saving is required. This dissertation aimed to explore some of these under-researched areas in a sample of sixteen persons with incomplete tetraplegia. Areas of focus included, 1) rehabilitation feasibility, adherence, and research challenges in an under-resourced environment 2) cardiovascular functioning and adaptation to a rehabilitation programme, and 3) psychological well-being. We implemented two interventions, robotic locomotor training (RLT) and activity-based training (ABT), over a 24-week pilot randomised control trial. Adherence to the interventions was high (93.9 ± 6.2%). Challenges to the study's feasibility included: ethical approval, medical clearance, transport and limited human/financial resources. Cardiovascular parameters demonstrated that efficiency of exoskeleton walking improved during the intervention. RLT may be more effective than ABT in improving cardiac responses to orthostatic stress, with standing heart rate at 24-weeks being significantly lower in the RLT group (75.1 ± 15.0 beats/min) compared to the ABT group (95.6 ± 12.6 beats/min). Standing and RLT had similar effects on the parasympathetic nervous system, whilst both interventions were limited in their effect on brachial and ankle blood pressure. Despite experiencing past trauma, participants possessed psychological resources including resilience, self-efficacy and post-traumatic growth which contributed to high perceptions of quality of life. The use of an exoskeleton may have had a greater positive impact on subjective psychological well-being. Expectations of participants entering the study centred around regaining the ability to walk again, despite past experiences and medical advice suggesting otherwise. Hope aids in buffering against negative emotions, however, a thin line exists between supporting high expectations and confronting unrealistic hope. Initial high expectations of recovery decreased and became more realistic during the intervention. This dissertation demonstrates potential physiological and psychological benefits that RLT provides. Despite this potential, barriers exist in the use of RLT in low- and middle-income countries such as South Africa, primarily due to a lack of financial and human resources. The development of lower-cost exoskeletons would lessen the burden of conducting large-scale trials and increase the likelihood of adopting these innovative rehabilitation tools into current standard of care practices.
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    Profiles of illness and injury among South African elite athletes with disability at the 2012 Summer Paralympic Games
    (2016) Constantinou, Demitri; Albertus, Yumna; Derman, Wayne
    Epidemiological data is important to better understand injury and illness patterns in para athletes. Medical teams used a web-based injury and illness surveillance system (WEB-IISS system) to all the para-athlete injuries and illnesses during the 2012 London Paralympic games. All team physicians could access the system at any time to log data, providing a vast database for potential research. The relative ease of data collection permits large amounts of data to be analysed, providing important surveillance data on injury and illness. Data on the South African para-athletes, provided by the team's Chief Medical Officer, were assessed and compared to all countries. This study aimed to describe the illness and injury profiles in South African elite paraathletes who participated in the 2012 Summer Paralympic Games; and compare these profiles to data from the other countries that participated. A retrospective sub-analysis of the data-set collected from a large prospective study of injury and illness at the London Summer Paralympic Games in 2012 was compared to data collected on all para-athletes from input by team physicians into the WEB-ISS system. In total, 62 South African para-athletes presented with 19 injuries, with an injury rate of 21.9 per 1000 athlete days. Twenty-five para-athletes presented illness, with an illness rate of 28.8 per 1000 athlete days. The overall injury and illness rate in the South African para-athletes was higher than the injury and illness rate in all para-athlete participants at the London Paralympic Games. The anatomical distribution of injuries (lower limbs, axial and upper limbs) and the nature of illness (respiratory, skin & subcutaneous and digestive systems) were however similar. Causative factors are not evident and need to be further studied. Increased efforts in injury and illness surveillance and preventative programmes should be employed to reduce the incidence of injury and illness, and their severity . Such efforts in para-athlete care should be ongoing with surveillance to monitor and manage trends to ensure the culmination of Paralympic competition does not result in high rates of injury and illness. Education of healthcare providers, para-athletes, coaches and others in the management of para-athletes, is key.
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    A randomised control trial for the restoration of functional ability in patients post total knee arthroplasty: a comparison of eccentric versus concentric cycling ergometry
    (2015) Bakkum, Amanda; Posthumus, Michael; Albertus, Yumna; Collins, Malcolm
    Purpose: The predominant impairment to function following a total knee arthroplasty (TKA) is a distinctive reduction in quadriceps muscle strength. It has been suggested that eccentric rehabilitation may be more beneficial than traditional concentric only rehabilitation at improving muscle strength, physical functioning and quality of life in this population. The aim of this study was therefore to determine if an eccentric cycling ergometry rehabilitation intervention (a) was feasible in participant's early after TKA surgery (Study 1), (b) resulted in greater improvements in muscle strength and endurance, as well as muscle activity and muscle volume (Study 2) and, (c)resulted in greater knee functional ability, health related quality of life and physical activity levels (Study 3), when compared to an concentric cycling ergometry rehabilitation intervention. Finally, knee and hip kinematics, ground reaction force and muscle activity was described during the sit-to-stand transfer within this population (Study 4). Methods: Eighteen age- and sex-matched participants', three to nine month's post-TKA were recruited and randomly divided into either an eccentric or concentric cycling rehabilitation intervention. The participants were required to perform three exercise sessions a week, over a period of eight weeks. Isokinetic strength and muscle activity of the quadriceps and hamstring muscles, sit-to-stand motion capture analysis and knee functional ability and health related quality of life questionnaires (Knee Injury and Osteoarthritis Outcome Score, SF-36Health Survey and Tegner Activity Scale) were assessed pre and post- rehabilitation intervention. Data Analysis: Two-way repeated-measures analysis of variance were used to analyse the effects of time and the ECC and CON intervention groups and the group/time interaction for each of the dependent variables. Results: The eccentric rehabilitation intervention was well tolerated with regards to pain levels in participants' as early as three months post-TKA, the peak level of pain perceived per session, never exceeding a "mild" classification. The eccentric intervention resulted in greater power (P= 0.029) and work output (P ≤ 0.001) with a reduced overall heart rate (P= 0.014) ; moderate decreases in biceps femoris (BF) muscle activity (-3.2%) and increases in the lean thigh volume (+807.32) of the uninvolved limb; as well as improvements in the physical fun ctioning (+12.2%) and physical role functioning SF-36 scores (+22.2%) and the level of physical activity (+0.9) (Tegner activity scale). The concentric intervention resulted in decreases in vastus lateralis (VL) muscle activity (-8.17%) and work fatigue (-7.34%) and increases in the lean thigh volume (+677.49) and the hip abduction angle (+ 2.67°) (sit-to-stand) of the involved limb. Conclusion: The eccentric rehabilitation intervention is well tolerated with regards to pain and is characterised by significantly greater power output produced and work performed at significantly lower heart rates. Eccentric cycling ergometry matched in perceived exertion and duration, is associated with greater improvements in physical functioning outcome scores, physical activity level and knee flexion muscle efficiency during concentric contractions, when compared with concentric cycling ergometry. However, knee extensor muscle endurance and efficiency during concentric contractions, as well as muscle volume of the involved limb increased more significantly after concentric training in comparison to eccentric training, Further research is required to establish which training modality is the most feasible and effective in restoring knee function in participant's three months post-TKA.
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    The Effect of Robotic Walking and Activity-based Rehabilitation on Functional Capacity, Secondary Complications & Psychological Well-being in Individuals with Spinal Cord Injury (SCI)
    (2021) Shackleton, Claire Lauren; Albertus, Yumna; West, Sacha; Derman, Wayne
    Activity-based training (ABT) represents the current standard of care in neurological rehabilitation centers around the world. However, innovative rehabilitation techniques have been developed including robotic locomotor training (RLT). The conceptual basis for RLT initially appeared promising; a rehabilitation modality that removes the need for intensive assistance from therapists, whilst facilitating safe and effective over-ground ambulation. However, small sample sizes and a lack of homogeneity across studies have resulted in an underpowered evidence base supporting the efficacy of RLT for SCI rehabilitation. Thus, this randomized control pilot study aimed to investigate the effects of RLT compared to ABT on functional capacity, secondary complications, and psychological well-being in people with SCI after 24-weeks of rehabilitation. Participants with chronic, traumatic motor incomplete SCI were randomized into two intervention groups: RLT (n = 8) and ABT (n = 8) groups. RLT involved solely walking in the Ekso bionic suit. ABT involved a variety of resistance, cardiovascular and flexibility training combined with regular weight-bearing in the standing position. Outcome measures, including functional strength, ambulatory function, pain, spasticity, bladder/bowel, bone density, body composition, quality of life (QoL) and depression were tested at baseline, 6, 12 and 24-weeks of the intervention. There were no significant differences between the intervention groups for lower or upper extremity motor scores (UEMS effect size (ES) = 0.30; LEMS ES = 0.07), back strength (ES = 0.14) and abdominal strength (ES = 0.13) after training. However, both groups showed a significant increase of 2.00 points in UEMS and a significant increase in abdominal strength from pre- to post intervention. Only the RLT group showed a significant change in LEMS, with a mean increase of 3.00 [0.00; 16.5] points over time. Distance walked in the Functional Ambulatory Inventory (SCI-FAI) increased significantly (p = 0.02) over time only for the RLT group. Therefore, the RLT showed promising evidence for potentially inducing functional strength changes and improvements in ambulatory function after 24 weeks of training. There was some evidence to support RLT to induce bowel improvements in individuals with SCI and both interventions appeared to reduce urinary incontinence and improve bladder function (p = 0.04). Total spasticity and pain intensity were similar between groups (p = 0.25; p = 0.96). However, pain interference ratings significantly increased from pre-post intervention for both groups (p = 0.05). RLT prevented the progressive decline of bone mineral density usually occurring in the SCI population, as hip BMD was maintained during RLT; however, it was significantly reduced (p = 0.04) during ABT, with a mean reduction of 0.06 [-0.34, 0.22] g/cm2 (5%) from pre to post intervention. No change in leg fat-free soft tissue mass (FFSTM) occurred between groups or over time (p = 0.32), however, there was a significant 7% increase in arm FFSTM over time for both groups (p < 0.01). The ABT group was more effective (ES = 1.02) in reducing central and peripheral adiposity, with a significant decrease in visceral adipose tissue (VAT) (p = 0.04) and gynoid FM (p = 0.01) over time. Both groups reported increased QoL and decreased depression ratings over time, with the RLT group having a significant change in the general life and physical health domains, p = 0.03, respectively. This pilot trial offers promising evidence for the effectiveness of RLT for improving functional and ambulatory capacity, reducing secondary complications, and potentially improving QoL in people with incomplete SCI. Thus, this dissertation adds substantial weight to the lacking evidence base on the effects of RLT, by incorporating a large homogenous sample, comprehensive testing procedures and an extended intervention period within South Africa.
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    Trail runners: Neuromuscular and biomechanical insights
    (2018) Bean, Rachel Christy Reid; Albertus, Yumna; Tam, Nicholas
    Running is a popular recreational and competitive sport worldwide. Despite numerous proven health benefits associated with road running, the risk of sustaining a running-related injury (RRI) is extremely high. The cause of RRI is multifactorial and the result of running many kilometres on monotonous and mechanically stiff road surfaces has been suggested to increase the risk of sustaining an injury. Interestingly, this notion may be a key driving factor for the emergence and growing interest in, trail or 'off-road’ running. Research investigating road running has been well-described, whereas the impact of regular running on natural, dynamic trail surfaces on the musculoskeletal system has yet to be fully considered. Thus, this thesis sought to understand the trail running athlete, with particular focus on elucidating the clinical, biomechanical and neuromuscular consequences of habitual running training on off-road terrain. The present thesis begins with a comprehensive review of the literature. The aim of this chapter was to briefly describe the origins of trail running, explore the theoretical driving factors behind interest in trail running, and detail the current scientific understanding of trail running and the purported implications and benefits thereof. Gaps in the existing body of knowledge were highlighted, with recommendations for necessary future research. The first study aimed to describe clinical measures of dynamic stability in well-trained trail runners and contrast this group with age- and performance-matched road runners. All runners performed three clinical assessments: the Star Excursion Balance Test (SEBT), Unilateral Bridge Hold (UBH) and Single Leg Squat (SLS). No differences were found in UBH and SEBT assessments. During the SLS task, trail runners exhibited less ankle varus and less ankle external rotation at peak knee flexion in comparison to road runners. These findings suggest that trail runners’ performance in the SLS test may represent a kinematic adaptation to habitual terrain targeted at minimising ankle joint movement during weight-bearing. Subsequently, we aimed to determine whether running biomechanics would differ between 20 habitually shod trail runners and 20 road running counterparts due to their preferred training terrain. A special focus of this chapter was to determine whether the groups of runners presented with disparate risk of sustaining a running-related injury (RRI). To evaluate this hypothesis, all runners performed barefoot and shod overground running trials on a synthetic track. Regardless of footwear condition, trail runners presented with greater step frequency, shorter ground contact time and shorter step duration. Further group differences were observed, with trail contact time and shorter step duration. Further group differences were observed, with trail runners exhibiting notably advantageous kinematics at the level of the ankle and the foot, presenting with: smaller foot strike angle, lower pronation magnitude and velocity, and lower ankle stiffness. Considering these biomechanical parameters, it was unexpected to find that trail runners experienced similar initial loading rates (ILRs) and higher ground reaction forces to road runners in response to the synthetic track. The final experimental chapter explored the notion that preferred running terrain has an influence on neuromuscular regulation of running biomechanics. To examine this, electromyography and biomechanical variables were determined using previously described protocols. Regardless of footwear condition, trail runners exhibited greater gluteus maximus, biceps femoris and peroneus longus muscle activation during terminal swing in comparison to road runners. In addition, trail runners exhibited greater tibialis anterior activation during early swing. With regards to discrete biomechanics, trail runners presented with greater lower extremity joint stability in the sagittal plane, demonstrating lower pelvic, hip and knee flexion at initial ground contact. Interestingly, similar ground reaction forces were experienced by trail and road runners on the synthetic track, suggesting that the observed muscle 'tuning’ responses to these impact forces may be managed by the differing neuromuscular responses. The outcomes of this thesis suggest that there are numerous clinical, mechanical and neuromuscular implications of habitual running training on the trail and road. Although the present thesis is the first step to understanding the demands of regular trail running on the human body, future studies using portable motion capture and inertial systems are necessary to determine the precise influence of real-time trail running on the neuromuscular system and running biomechanics. Interestingly, trail runners demonstrated several purported 'advantageous’ kinematic and spatiotemporal parameters, and exhibited differing muscle activity patterns in comparison to road runners in a controlled laboratory setting. However, trail and road runners experienced similar ILRs in response to the synthetic track. Considering the high incidence of road RRI, and that higher vertical load has been associated with chronic RRI, this finding suggests that trail and road runners could be at similar risk of developing a RRI. However, due to the disparate nature of trail and road running terrains and the multifactorial nature of RRIs, further clarity on 1) the acute and long-term effects of off-road running and 2) the injury risk profile of a trail runner, is imperative for a holistic understanding of the risks and benefits associated with participation in this sport. We recommend that the influence of trail running on the musculoskeletal system presented in this thesis be considered as a foundation for future large-scale epidemiological and prospective injury research.
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    Understanding risk of injury in novice runners: exploring the link between runner characteristics, biomechanics and injury outcome
    (2020) Coetzee, Devon Ross; Tucker, Ross; Albertus, Yumna; Tam, Nicholas
    The high prevalence of running related injury, particularly in novice runners has prompted the investigation into interventions to mitigate the risk of injury. This dissertation set out to investigate the effects of a progressive 12-week running intervention in novice runners wearing footwear with reduced cushioning. The aim was to understand how intrinsic characteristics of novice runners, namely body composition, strength and flexibility, influence running biomechanics and ultimately injury outcome, and whether footwear structure effects this relationship. Prior to the intervention, participants were assigned to wearing footwear with reduced cushioning (RC) or footwear with traditional cushioning (TC). Three-dimensional running biomechanics were collected during over ground running at 3.0 meters per second in their prescribed footwear. Other measured variables included lower limb strength, by means of an isokinetic dynamometer, lower limb flexibility, full body composition by means of Duel Energy X-Ray Absorptiometry and lower leg bone oedema by means of magnetic resonance imaging. Throughout the intervention, pain or discomfort was assessed. All variables were reassessed after the intervention. The programme used in this thesis resulted in a 11.1 % prevalence of injury, which is considerably lower than other studies. No differences in injury incidence, bone oedema or pain or discomfort prevalence were found between footwear groups, however the RC group experienced pain or discomfort more frequently. Footwear with reduced cushioning was found to promote kinematic strategies, including a lower foot strike angle (FSA), more flexed knee angle at foot strike and reduced knee range of motion during stance phase to compensate for the lack of cushioning. Whilst most novice runners adopted a rear foot strike pattern throughout the intervention, the RC group were four times more likely to reduce FSA. Intrinsic characteristics of novice runners may not be indicative of injury, however the intervention resulted in changes to these variables. These included improvements in movement-specific strength, increased passive hip flexor flexibility and weight loss. Footwear had no effect on these variables. Greater mass characteristics resulted in kinematic adaptations in the knee. This dissertation highlighted the importance of a conservative training structure to mitigate injury risk in novice runners. Additionally, footwear has limited effect on injury risk and thus should not be prescribed to promote biomechanical change, but rather to compliment a runner's current biomechanics and intrinsic characteristics.