Oral application of L-menthol in the heat: From pleasure to performance

When menthol is applied to the oral cavity it presents with a familiar refreshing sensation and cooling mint flavour. This may be deemed hedonic in some individuals, but may cause irritation in others. This variation in response is likely dependent upon trigeminal sensitivity toward cold stimuli, suggesting a need for a menthol solution that can be easily personalised. Menthol’s characteristics can also be enhanced by matching colour to qualitative outcomes; a factor which can easily be manipulated by practitioners working in athletic or occupational settings to potentially enhance intervention efficacy. This presentation will outline the efficacy of oral menthol application for improving time trial performance to date, either via swilling or via co-ingestion with other cooling strategies, with an emphasis upon how menthol can be applied in ecologically valid scenarios. Situations in which performance is not expected to be enhanced will also be discussed. An updated model by which menthol may prove hedonic, satiate thirst and affect ventilation will also be presented, with the potential performance implications of these findings discussed and modelled. Qualitative reflections from athletes that have implemented menthol mouth swilling in competition, training and maximal exercise will also be included

SIMBIO-M 2014, SIMulation technologies in the fields of BIO-Sciences and Multiphysics: BioMechanics, BioMaterials and BioMedicine, Marseille, France, june 2014

Proceedings de la 3ème édition de la conférence internationale Simbio-M (2014). Organisée conjointement par l'IFSTTAR, Aix-Marseille Université, l'université de Coventry et CADLM, cette conférence se concentre sur les progrès des technologies de simulation dans les domaines des sciences du vivant et multiphysiques: Biomécanique, Biomatériaux et Biomédical. L'objectif de cette conférence est de partager et d'explorer les résultats dans les techniques d'analyse numérique et les outils de modélisation mathématique. Cette approche numérique permet des études prévisionnelles ou exploratoires dans les différents domaines des biosciences

A STEP TOWARDS UNDERSTANDING BALANCE CONTROL IN INDIVIDUALS WITH INCOMPLETE SPINAL CORD INJURY

Purpose: Frequent falls are reported by individuals with spinal cord injury (SCI) suggesting impairments in their balance control. This thesis examined balance assessment and balance control in individuals with SCI. Methods and Results: To investigate the effects of light touch on standing balance, center of pressure (COP) sway during standing was measured in 16 participants with incomplete SCI (iSCI) and 13 able-bodied (AB) participants. Participants with iSCI showed reduction in COP sway with light touch similar to AB participants. To study the association between stability during normal walking (NW) and unexpected slip intensity, NW behaviour and intensity of an unexpected slip perturbation were assessed in 20 participants with iSCI, and 16 AB participants. Participants with iSCI demonstrated greater stability by walking slower, taking shorter steps, and more time in double support. Walking slower was associated with lower slip intensity in individuals with iSCI. To study reactive balance control, change in margin of stability with a compensatory step, activation of lower extremity muscles, and change in limb velocity trajectories in response to an unexpected slip perturbation were studied in 16 participants with iSCI and 13 AB participants. Participants with iSCI demonstrated limitations in reactive responses including a smaller increase in lateral margin of stability, slower onset of trail limb tibialis anterior activity, and decreased magnitude of trail limb soleus activity. To identify balance measures specific to individuals with SCI, a systematic review of 127 articles was conducted. Thirty balance measures were identified; 11 evaluated a biomechanical construct and 19 were balance scales designed for use in clinical settings. All balance scales had high clinical utility. The Berg Balance Scale and Functional Reach Test were valid and reliable, while the Mini Balance Evaluation Systems Test was most comprehensive. Conclusions: Individuals with iSCI have impaired balance control, as evidenced by limitations in reactive balance; however, they have the ability to modify their balance, as demonstrated by greater stability during NW and with light touch while standing. No single balance measure met all criteria of a useful measure - high clinical utility, strong psychometric properties, and comprehensiveness in the SCI population. Combined, the findings highlight the need for the comprehensive assessment and rehabilitation of balance control after iSCI

Cognitive social and affective neuroscience of patients with spinal cord injury

A successful human-environment interaction requires a continuous integration of information concerning body parts, object features and affective dynamics. Multiple neuropsychological studies show that tools can be integrated into the representation of one's own body. In particular, a tool that participates in the conscious movement of the person is added to the dynamic representation the body – often called “Body schema” – and may even affect social interaction. In light of this the wheelchair is treated as an extension of the disabled body, essentially replacing limbs that don't function properly, but it can also be a symbol of frailty and weakness. In a series of experiments, I studied plastic changes of action, tool and body representation in individuals with spinal cord injury (SCI). Due to their peripheral loss of sensorimotor functions, in the absence of brain lesions and spared higher order cognitive functions, these patients represent an excellent model to study this topic in a multi-faceted way, investigating both fundamental mechanisms and possible therapeutic interventions. In a series of experiments, I developed new behavioral methods to measure the phenomenological aspects of tool embodiment (Chapter 3), to study its functional and neural correlates (Chapter 4) and to assess the possible computational model underpinning these phenomena (Chapter 5). These tasks have been used to describe changes in tool, action and body representation following the injury (Chapter 3 and 4), but also social interactions (Chapter 7), with the aim of giving a complete portrait of change following such damage. I found that changes in the function (wheelchair use) and the structure (body brain disconnection) of the physical body, plastically modulate tool, action and body representation. Social context and social interaction are also shaped by the new configuration of bodily representations. Such a high degree of plasticity suggests that our sense of body is not given at once, but rather it is constantly constructed and adapted through experience

Changes in temperature of heel skin under pressure in hip surgery patients

OBJECTIVE: The aim of the study was to examine the effect of external pressure of the bed surface on heel skin temperature in adults in the first 3 days after hip surgery. DESIGN: A quasi-experimental study in a prospective, within-subjects, repeated-measures design. SETTING: This study was performed at 2 acute-care hospitals. PARTICIPANTS: Eighteen subjects (9 men and 9 women) with a mean age of 58.3 (±16.1) years were recruited after hip surgery at the 2 hospitals. METHODS: Temperature sensors were placed on the plantar surface of each foot, close to the heels. Measures were taken when the heels were (1) suspended above the bed surface for 20 minutes (preload), (2) on the bed surface for 15 minutes (loading), and (3) suspended again above the bed surface for 15 minutes (unloading). MAIN OUTCOME MEASURES: Heel skin temperature and demographic data. RESULTS: Heel temperature increased during loading and unloading in both legs on postoperative days 1 (P = .003) and 3 (P = .04) but not on postoperative day 2. Heel temperature in the nonoperative leg decreased in the first 3 minutes of unloading on postoperative days 2 (P = .02) and 3 (P .01). CONCLUSION: Heel temperature increased with loading and unloading on postoperative days 1 and 3. Upon immediate unloading, hyperemic response was present only in the nonoperative leg. Keeping the heels off the bed surface at all times may avoid heel skin temperature changes and prevent tissue damage. Further research is needed to identify the mechanisms that explain the effect of external pressure on heel temperature

Thermoregulatory responses of athletes with a spinal cord injury during rest and exercise

Following on from Rio de Janeiro 2016, the Tokyo 2020 Paralympic Games will present a unique challenge for athletes, needing to prepare and adapt to the potential challenging environmental conditions of 20-27°C and ~73% relative humidity. It is well known that during exercise in hot and/or humid climates, able-bodied athletes experience an increase in thermal strain and a reduction in performance compared to cooler/drier conditions. Yet these conditions prove even more problematic for athletes, who as a consequence of their impairment have a dysfunctional thermoregulatory system, such as athletes with a spinal cord injury (SCI). To date, the thermoregulatory responses of athletes with an SCI have been an under-studied area of research. To gain a greater understanding of how heat balance is altered in individuals with an SCI and the thermoregulatory consequences as a result, studies need to first be conducted at rest, removing the additional metabolic heat production from exercise. Although a large majority of athletes with an SCI compete indoors in wheelchair court sports (e.g. wheelchair basketball and rugby), exercising even in these climate-controlled environments has been shown to place these athletes under considerable thermal strain. In light of this, it is remarkable that existing research on the thermoregulatory responses of athletes with an SCI during exercise is scarce, especially studies encompassing “real-world” sporting environments. Athletes with high level lesions (tetraplegia, TP) are a particularly under-studied population group shown to have a greater thermoregulatory impairment than individuals with low level lesions (paraplegia, PA) during continuous exercise. Thus the aim of this thesis was to investigate the thermoregulatory responses of athletes with an SCI at rest and during “real-world” sporting scenarios, with specific focus on athletes with TP. Study 1 aimed to determine how evaporative heat loss is altered, as a result of an SCI, compared to the able-bodied (AB), and the effect lesion level has on this response. The results provide evidence that in individuals with TP, even at rest, evaporative heat loss is not large enough to balance the heat load, when evaporation is the primary source of heat dissipation. Even though in individuals with PA Tgi increased by a smaller magnitude and they possessed a greater sweating capacity than individuals with TP, at ambient temperatures above Tsk latent heat loss is insufficient to attain heat balance, compared to the AB. To investigate the thermoregulatory responses of athletes with an SCI during “real-world” sporting scenarios Study 2 examined athletes with TP compared to athletes with PA during 60 min of intermittent sprint wheelchair exercise on a wheelchair ergometer. The study was conducted in conditions representative of an indoor playing environment for wheelchair rugby and basketball (~21°C, 40% relative humidity). Results demonstrated that, despite similar external work, athletes with TP were under greater thermal strain than athletes with PA. Study 3’s novel approach investigated both physiological responses and activity profiles of wheelchair rugby players during competitive match play. Despite players with TP covering 17% less distance and pushing on average 10% slower, they were under a greater amount of thermal strain than players with non-spinal related physical impairments (NON-SCI). Furthermore, this study demonstrated that players with TP that had a larger body mass, larger lean mass, covered a greater relative distance and/or were a higher point player had a greater end Tgi. These data provide an insight for coaches and support staff regarding which players may need greater attention in regards to cooling strategies or breaks in play. The effectiveness of cooling practices currently employed by athletes with TP has not been previously investigated. Study 4 determined the effectiveness of pre-cooling, using an ice vest alone and in combination with water sprays between quarters, at attenuating thermal strain in athletes with TP. Using the activity profile data from Study 3, an intermittent sprint protocol, conducted on a wheelchair ergometer, was used to represent a wheelchair rugby match. The combination of cooling methods lowered Tgi and Tsk to a greater extent than pre-cooling only, despite neither cooling condition having a positive or negative effect on performance. Unexpectedly, the pre-cooling only condition lowered Tgi, compared to no cooling, throughout the subsequent exercise protocol, even though the reduction in Tsk was not long lasting. This thesis provides comprehensive evidence that athletes with TP experience heightened thermal strain during both rest and “real-world” sporting scenarios compared to the AB, athletes with PA, and within the sport of wheelchair rugby. Athletes with TP should employ practices, such as appropriate cooling methods or alter playing tactics to reduce thermal strain and the likelihood of attaining a heat related injury

Thermoregulatory responses of athletes with a spinal cord injury during rest and exercise

Following on from Rio de Janeiro 2016, the Tokyo 2020 Paralympic Games will present a unique challenge for athletes, needing to prepare and adapt to the potential challenging environmental conditions of 20-27°C and ~73% relative humidity. It is well known that during exercise in hot and/or humid climates, able-bodied athletes experience an increase in thermal strain and a reduction in performance compared to cooler/drier conditions. Yet these conditions prove even more problematic for athletes, who as a consequence of their impairment have a dysfunctional thermoregulatory system, such as athletes with a spinal cord injury (SCI). To date, the thermoregulatory responses of athletes with an SCI have been an under-studied area of research. To gain a greater understanding of how heat balance is altered in individuals with an SCI and the thermoregulatory consequences as a result, studies need to first be conducted at rest, removing the additional metabolic heat production from exercise. Although a large majority of athletes with an SCI compete indoors in wheelchair court sports (e.g. wheelchair basketball and rugby), exercising even in these climate-controlled environments has been shown to place these athletes under considerable thermal strain. In light of this, it is remarkable that existing research on the thermoregulatory responses of athletes with an SCI during exercise is scarce, especially studies encompassing real-world sporting environments. Athletes with high level lesions (tetraplegia, TP) are a particularly under-studied population group shown to have a greater thermoregulatory impairment than individuals with low level lesions (paraplegia, PA) during continuous exercise. Thus the aim of this thesis was to investigate the thermoregulatory responses of athletes with an SCI at rest and during real-world sporting scenarios, with specific focus on athletes with TP. Study 1 aimed to determine how evaporative heat loss is altered, as a result of an SCI, compared to the able-bodied (AB), and the effect lesion level has on this response. The results provide evidence that in individuals with TP, even at rest, evaporative heat loss is not large enough to balance the heat load, when evaporation is the primary source of heat dissipation. Even though in individuals with PA Tgi increased by a smaller magnitude and they possessed a greater sweating capacity than individuals with TP, at ambient temperatures above Tsk latent heat loss is insufficient to attain heat balance, compared to the AB. To investigate the thermoregulatory responses of athletes with an SCI during real-world sporting scenarios Study 2 examined athletes with TP compared to athletes with PA during 60 min of intermittent sprint wheelchair exercise on a wheelchair ergometer. The study was conducted in conditions representative of an indoor playing environment for wheelchair rugby and basketball (~21°C, 40% relative humidity). Results demonstrated that, despite similar external work, athletes with TP were under greater thermal strain than athletes with PA. Study 3 s novel approach investigated both physiological responses and activity profiles of wheelchair rugby players during competitive match play. Despite players with TP covering 17% less distance and pushing on average 10% slower, they were under a greater amount of thermal strain than players with non-spinal related physical impairments (NON-SCI). Furthermore, this study demonstrated that players with TP that had a larger body mass, larger lean mass, covered a greater relative distance and/or were a higher point player had a greater end Tgi. These data provide an insight for coaches and support staff regarding which players may need greater attention in regards to cooling strategies or breaks in play. The effectiveness of cooling practices currently employed by athletes with TP has not been previously investigated. Study 4 determined the effectiveness of pre-cooling, using an ice vest alone and in combination with water sprays between quarters, at attenuating thermal strain in athletes with TP. Using the activity profile data from Study 3, an intermittent sprint protocol, conducted on a wheelchair ergometer, was used to represent a wheelchair rugby match. The combination of cooling methods lowered Tgi and Tsk to a greater extent than pre-cooling only, despite neither cooling condition having a positive or negative effect on performance. Unexpectedly, the pre-cooling only condition lowered Tgi, compared to no cooling, throughout the subsequent exercise protocol, even though the reduction in Tsk was not long lasting. This thesis provides comprehensive evidence that athletes with TP experience heightened thermal strain during both rest and real-world sporting scenarios compared to the AB, athletes with PA, and within the sport of wheelchair rugby. Athletes with TP should employ practices, such as appropriate cooling methods or alter playing tactics to reduce thermal strain and the likelihood of attaining a heat related injury

The Effect of Robotic Walking and Activity-based Rehabilitation on Functional Capacity, Secondary Complications & Psychological Well-being in Individuals with Spinal Cord Injury (SCI)

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

A HAPA Inspired, Agent-Based Model and Simulation of Activity in an Online Community

This thesis is an examination of a Health Action Process Approach (HAPA) developed originally by R. Schwarzer for use in understanding and effecting health behaviour adoption. Although HAPA provides an integral aspect of formulating health treatment strategies by human practitioners for human patients, at the present time no simulation models suited to computer implementation and usage exist for the study of and support for health behaviour adoption within a HAPA framework. This thesis examines the relevant research with respect to HAPA and the components necessary to build a simulation model and platform for an online, self-managing SCI community. We design an architecture for the platform that satisfies the primary requirements suggested by HAPA and SCI patients, particularly directed at gathering relevant data consisting of health indicators. Also, we develop several algorithms used for analysis of HAPA related health states and transitions between states. Since this research did not involve any human subjects, the intention was to simulate certain critical behaviours and changes using an agent based modeling approach. Inasmuch as agents can provide only approximations to real human behaviour, they are still useful and informative. As part of our results, we show that an automated HAPA classification can reduce the risk of agents dropping a health behaviour or program due to misclassification. Further, findings revealed that 6% of the agents are in danger of dropping the adoption of an individual health behaviour within two weeks and that 14% of the agents are at risk of dropping out of the community without continual HAPA reclassification