The effects of protective clothing and its properties on energy consumption during different activities

There are many situations where workers are required to wear personal protective clothing (PPC), to protect against a primary hazard, such as heat or chemicals. But the PPC can also create ergonomic problems and there are important side effects which typically increase with rising protection requirements. The most extensively studied side effect is that of increased heat strain due to reduced heat and vapour transfer from the skin. Less studied is the extra weight, bulk and stiffness of PPC garments which is likely to increase the energy requirements of the worker, reduce the range of movement and lead to impaired performance. Current heat and cold stress standards assume workers are wearing light, vapour permeable clothing. By failing to consider the metabolic effects of actual PPC garments, the standards will underestimate heat production and therefore current standards cannot be accurately applied to workers wearing PPC. Information on the effect of the clothing on the wearer and the interactions between PPC, wearer and environment is limited. Data was collected to quantify the effect of PPC on metabolic load based on the properties of the PPC for the EU THERMPROTECT project (GERD-CT-2002-00846). The main objective of the project was to provide data to allow heat and cold stress assessment standards to be updated so that they need no longer exclude specialised protective clothing. The aim of this thesis was to investigate the effect of PPC and its properties on energy consumption during work. For this purpose, the effects of a range of PPC garments (Chapter 3), weight (Chapter 4), number of layers and material friction (Chapter 5) and wet layers (Chapter 6) on energy consumption whilst walking, stepping and completing an obstacle course were studied. The impact of PPC on range of movement in the lower limbs was also investigated (Chapter 7). The main findings were; a) Increased metabolic cost of 2.4 - 20.9% when walking, stepping and completing an obstacle course in PPC compared to a control condition. b) An average metabolic rate increase of 2.7% per kg increase in clothing weight, with greater increases with clothing that is heavier on the limbs and in work requiring greater ranges of movement. c) 4.5 to 7.9% increase in metabolic cost of walking and completing an obstacle course wearing 4 layers compared to a single layer control condition of the same weight. d) Changes in range of movement in PPC due to individual behavioural adaptations. e) Garment torso bulk is the strongest correlate of an increased metabolic rate when working in PPC (r=0.828, p<0.001). f) Garment leg bulk (r=0.615), lower sleeve weight (r=0.655) and weight of the garment around the crotch (r=0.638) are also all positively correlated with an increased metabolic rate. Total clothing weight and clothing insulation had r values of 0.5 and 0.35 respectively. This thesis has confirmed the major effect of clothing on metabolic rate, and the importance of including this effect in standards and models

The biomechanics of military load carriage and injury potential

This thesis consisted of two main research themes: 1) The biomechanics of military load carriage, and 2) injuries and discomfort caused by load carriage. Although different in their methodological approaches, the two sections are linked and integral to each other. Harman et al (2000) suggest that the biomechanical analysis of military load carriage, and in particular the study of ground reaction forces (GRF), is relevant to the understanding and prevention oflower extremity injuries. The general aims of the biomechanical analysis of load carriage were to determine the effect that heavy load carriage, rifle carriage and load distribution has on GRF parameters. In addition to determining the mechanisms behind these potential changes, base-line data for British military load carriage systems (LCS) were also established. An important factor for the thesis was to consider the LCS as a single unit (where possible) and not its individual components, for example the backpack alone. The final biomechanical study involved a 3D, bi-Iateral gait analysis of load carriage; with this type of analysis being rare in the published literature. Results from the biomechanical studies showed that GRF parameters increased proportionally to applied load, even when heavy loads of up to 40 kg were carried. Also seen was an increase in mediolateral impulse and stance time with greater carried load. Another area which has received little or no attention in the literature is the effect of rifle carriage on gait. This thesis showed that rifle carriage changed basal gait patterns as observed in the GRF parameters. The most noteworthy results were an increase in impact peak and mediolateral impulse. The mechanism behind these changes is most likely to be a restriction of natural arm swing induced by rifle carriage. Distributing load more evenly around the body had limited effect on the GRF parameters measured. However, some important changes were observed. These were an increase in force minimum and a decrease in maximum braking force at the heaviest load. The latter effect has been strongly linked to an increase in the incidence of foot blisters within the literature. Finally, the gait analysis study showed significant increases in joint moments and torques with carried load. Also observed was a decrease in stride length and increase in percentage double support and stance. The main kinematic differences were a decrease in range of motion at the knee and pelvis rotation, and an increase in pelvis tilt as load is added. Four further studies were conducted in an effort to determine the discomfort and injury caused by load carriage. The first 3 studies collected sUbjective discomfort data via interviews, questionnaires and the use of comfort ratings. All of which were collected either during or after a prolonged period of load carriage by military personnel. Results gleaned from these studies showed that the upper limb is susceptible to short term discomfort following load carriage, whereas the lower limb is not. The lower limb may be at an increased risk of developing medium to long term injuries such as joint degradation and stress fractures. However, foot pain was rated as the most uncomfortable skeletal region of the body following a 1 hour field march with load, and blisters were experienced by around 60% of participants. Shoulder discomfort commences almost as soon as load is added and increases steadily with time. However, foot discomfort seems to increase more rapidly once the discomfort first materialises. This early development of shoulder or foot pain may be a risk factor for severe pain or non-completion of a period of prolonged load carriage. Finally, females experienced more discomfort in the hip joint and feet compared to males. (Continues...).EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Ski Boots Do Not Impair Standing Balance by Restricting Ankle-Joint Mobility

International audienc

Analysis of the backpack loading efects on the human gait

Gait is a simple activity of daily life and one of the main abilities of the human being. Often during leisure, labour and sports activities, loads are carried over (e.g. backpack) during gait. These circumstantial loads can generate instability and increase biomechanicalstress over the human tissues and systems, especially on the locomotor, balance and postural regulation systems. According to Wearing (2006), subjects that carry a transitory or intermittent load will be able to find relatively efficient solutions to compensate its effects.info:eu-repo/semantics/publishedVersio

NURSE-DELIVERED SHOE-LACING INTERVENTION: EFFECT ON COMFORT AND TOE PRESSURES FOR ACTIVE COMMUNITY-DWELLING ADULTS (AGE 65+)

Significance: Problems with shoe fit are endemic, affect gait and balance and lead to falls. Falls are physically, emotionally, and economically costly. Low-cost, easily implemented interventions, that reduce pain and improve balance meet the “triple aim” of the Institute for Healthcare Improvement. Purpose: Evaluate the impact on community-dwelling adults (65+) of two nursing interventions involving foot repositioning and shoe relacing. Outcome measures: Toe pressures, experiences of pain and comfort. Method: Repeated-measures, mixed-methods lab-based study. Walk #1 Control. Intervention #1, participant’s heel secured to back of shoe, the participant’s chosen lacing pattern snugged. Intervention #2, heel secured to back of shoe, specific lacing pattern snugged. Results: 19 participants, aged 65-91(Av 74.7), 14 women, 5 men. When the participant’s heel was secured to back of shoe, and their chosen lacing was snugged (Intervention #1), there were 129/190 (68%) decreases in average peak toe pressures and 57% (11/19) stated there was an improvement in comfort. When the heel was secured to back of shoe, and a specific lacing pattern snugged. (Intervention #2) there were 148/190 (78%) decreases in average toe pressures and 133/190 (70%) decreases of Intervention #2 over Intervention #1. 63% (12/19) experienced greater comfort over Intervention #1. Orders of magnitude of the changes varied. ANOVA and two sample t-tests resulted in statistical significance on the 2nd and 4th left toes. This study was fueled by observations of nurses operating in the field doing foot care, who are trying to enhance mobility and quality of life for older people desiring to remain in their communities. The strength is the simplicity of the intervention and the focus on older adults and combination of qualitative and quantitative data that offset many of the weaknesses of each method. Limitations of this study were the sample was small, not diverse and the lab based nature of this study excluded those less able who are make up a large segment of the older adult population. Conclusion: Results supported the initial hypotheses that changing the foot position in a shoe and the lacing pattern can positively impact experiences of comfort/pain and reduce toe pressures

An integrated approach to whole-body vibration

Obiettivo di questa tesi è la determinazione e quantificazione degli effetti della whole-body vibration al corpo umano, in termini di consumo energetico, tramite un approccio globale e integrato. L’obiettivo è ottenuto considerando il corpo umano come una struttura organica complessa. Allo scopo di comprendere come questo risponda alle vibrazioni verticali, il consumo energetico del corpo umano è stato misurato per mezzo della variazione della temperatura superficiale con tecniche di misurazione a termografia infrarossa. Lo spostamento dei muscoli invece con il sistema di analisi di movimento Vicon MX. Infine, per quanto riguarda il consumo di ossigeno con il sistema telemetrico Cosmed K4. Il primo passo è stato l’istituzione di un protocollo appropriato che soddisfi l’obiettivo di questo studio. Infatti, la mancanza di coerenza nei protocollo di whole-body vibration che si trovano allo stato dell’arte, ha reso essenziale l’istituzione di un apposito protocollo, ed a questo scopo è stata definita la struttura dell’esperimento. Di conseguenza, è stata avviata una serie di prove per esaminare la risposta del corpo umano alle vibrazioni verticali, cambiando la durata e la frequenza della vibrazione, nonché la durata del periodo di riposo. In totale, quattro persone in piedi sono state sottoposte a vibrazioni verticali, in una pedana vibrante, a frequenze da 20 a 50 Hz. Dopo l’instaurazione del protocollo finale, sono stati avviate una serie di prove di laboratorio. In particolare, sono state scelte tre frequenze per le vibrazioni: 20, 30 e 45 Hz. I risultati ottenuti più interessanti di questo studio, riguardano il consumo di ossigeno, la temperatura superficiale e i coefficienti di trasmissibilità dell’accelerazione.The objective of this thesis is to determine and quantify the effects of whole-body vibration to the human body in terms of energy expenditure, by means of a global and integrated approach. This objective is attained by considering the human body as a complex organic structure. In order to understand how it responds to vertical vibrations, the energy expenditure of the human body was measured by means of the variation in superficial temperature with the aid of infrared thermography, the displacement of the muscles with the aid of the Vicon MX motion analysis system and the oxygen uptake with the aid of the Cosmed K4 telemetric system. The establishment of an appropriate protocol which satisfies the aim of this study was the first goal. The lack of consistency in whole-body vibration protocols in the current published studies makes the establishment of an appropriate protocol essential, and in this sense, an experiment setup was implemented. Therefore, a series of experiments was conducted to examine the response of the human body to vertical vibrations, changing the duration and the frequency of vertical vibration, and the duration of rest period. A number of four persons were subjected to vertical vibrations on a vibrating table in a standing position at a frequency ranging from 20 to 50 Hz. After the establishment of the final protocol, a series of laboratory experiments took place. Three different vibration frequencies were chosen: 20, 30 and 45 Hz corresponding to three different tests. The most interesting findings regard the oxygen consumption, the superficial temperature evolution, and the transmissibility coefficients for the acceleration

Fear of crime and victimization among the elderly participating in the self-defence course

Purpose. Self-defence training could enhance seniors´ defensive skills and fitness. There is lack of evidence about fear and concerns of seniors participating in the self-defence course. Methods. 18 elderly persons (16 female, 1 male; age 66.2, SD=5.86) participated in the self-defence course lasting 8 training units (each unit 60 minutes). Standardized tool for fear of crime and victimization analysis previously used in Euro-Justis project in the Czech Republic (2011) was used in pretest and posttest. Results. We explored the highest fear of crime by participants in their residence area after dark (mean=2,77; median=3; SD=0,80), lower fear at the night in their homes (mean=2,29; median=2; SD=0,75) and in their residence area at the daytime (mean=2,00; median=2; SD=0,77) at the beginning of the course. We noticed certain decrease of fear of crime after the intervention. Participant were less afraid of crime in their residence area after dark (mean=2,38; median=2; SD=0,77), they felt lower fear of crime at the night in their homes (mean=2,00; median=2; SD=0,48) and in their residence area at the daytime (mean=1,82; median=2; SD=0,63). Conclusions. The approach to self-defence teaching for elderly should be focused not just on the motor development, but also on their emotional state, fear of crime, perception of dangerousness of diverse situations and total wellbeing. Fear of crime analysis can contribute to create tailor made structure of the self-defence course for specific groups of citizens

The frequency of falls in children judo training

Purpose: Falling techniques are inseparable part of youth judo training. Falling techniques are related to avoiding injuries exercises (Nauta et al., 2013). There is not good evidence about the ratio of falling during the training in children. Methods: 26 children (age 8.88±1.88) were video recorded on ten training sessions for further indirect observation and performance analysis. Results: Research protocol consisted from recording falls and falling techniques (Reguli et al., 2015) in warming up, combat games, falling techniques, throwing techniques and free fighting (randori) part of the training session. While children were taught almost exclusively forward slapping roll, backward slapping roll and sideward direct slapping fall, in other parts of training also other types of falling, as forward fall on knees, naturally occurred. Conclusions: Judo coaches should stress also on teaching unorthodox falls adding to standard judo curriculum (Koshida et al., 2014). Various falling games to teach children safe falling in different conditions should be incorporated into judo training. Further research to gain more data from groups of different age in various combat and non-combat sports is needed

Muscle activation patterns in shoulder impingement patients

Introduction: Shoulder impingement is one of the most common presentations of shoulder joint problems 1. It appears to be caused by a reduction in the sub-acromial space as the humerus abducts between 60o -120o – the 'painful arc'. Structures between the humeral head and the acromion are thus pinched causing pain and further pathology 2. Shoulder muscle activity can influence this joint space but it is unclear whether this is a cause or effect in impingement patients. This study aimed to observe muscle activation patterns in normal and impingement shoulder patients and determine if there were any significant differences. Method: 19 adult subjects were asked to perform shoulder abduction in their symptomatic arm and non-symptomatic. 10 of these subjects (age 47.9 ± 11.2) were screened for shoulder impingement, and 9 subjects (age 38.9 ± 14.3) had no history of shoulder pathology. Surface EMG was used to collect data for 6 shoulder muscles (Upper, middle and lower trapezius, serratus anterior, infraspinatus, middle deltoids) which was then filtered and fully rectified. Subjects performed 3 smooth unilateral abduction movements at a cadence of 16 beats of a metronome set at 60bpm, and the mean of their results was recorded. T-tests were used to indicate any statistical significance in the data sets. Significance was set at P<0.05. Results: There was a significant difference in muscle activation with serratus anterior in particular showing a very low level of activation throughout the range when compared to normal shoulder activation patterns (<30%). Middle deltoid recruitment was significantly reduced between 60-90o in the impingement group (30:58%).Trends were noted in other muscles with upper trapezius and infraspinatus activating more rapidly and erratically (63:25%; 60:27% respectively), and lower trapezius with less recruitment (13:30%) in the patient group, although these did not quite reach significance. Conclusion: There appears to be some interesting alterations in muscle recruitment patterns in impingement shoulder patients when compared against their own unaffected shoulders and the control group. In particular changes in scapula control (serratus anterior and trapezius) and lateral rotation (infraspinatus), which have direct influence on the sub-acromial space, should be noted. It is still not clear whether these alterations are causative or reactionary, but this finding gives a clear indication to the importance of addressing muscle reeducation as part of a rehabilitation programme in shoulder impingement patients