The objective of the present study was to establish effective combinations of marching speed and backpack load in order to meet specific military requirements. Thirty infantrymen from the South African National Defence Force (SANDF) comprised the sample and experimental procedures were conducted in a laboratory setting using a Cybex Trotter treadmill. Sixteen conditions were set up which included combinations of four speeds (3.5, 4.5, 5.5, and 6.5 km.h⁻¹) and four backpack loads (20, 35, 50, and 65kg). Each subject was required to complete 8 of the sixteen conditions, each consisting of a six-minute treadmill march. Physiological data (heart rate, ventilation and metabolic responses), kinematic gait responses (step-rate and stride length) and perceptions of exertion (“Central” and “Local” RPE) were collected during the third and sixth minutes of the treadmill march and areas of body discomfort were identified post-march. Responses revealed five distinct categories of exertional strain. Three marches constituted “nominal” (below 40% VO₂max) and three “excessive” strain (above 75% VO₂ max). These represent combinations of extreme military demands and are highly unlikely to be utilised by the military. Three “tolerable” levels of required effort were recommended and these 10 combinations were further divided into three sub-categories. The “moderate” stress marches were identified as “ideal” for prolonged marches and had statistically similar responses of working heart rates (range of 118 bt.min⁻¹ to 127 bt.min⁻¹), energy expenditure (26 kJ.min⁻¹ and 27 kJ.min⁻¹) and ratings of perceived exertion (“Central” ratings of 10 and 11). Thus, marching at 5.5 km.h⁻¹with 20kg, 4.5 km.h⁻¹ with 35kg or 3.5 km.h⁻¹ with 50kg all require a similar energy cost. Four “heavy” category marches were identified for possible use when the duration of the march is reduced. During these marches responses were statistically similar with heart rates ranging from 127 bt.min⁻¹ to 137 bt.min⁻¹, energy expenditure from 32 kJ.min⁻¹ to 37 kJ.min⁻¹ and “Central” ratings of perceived exertion were 12 and 13. When short, high intensity marches are necessary, then combinations from the “very heavy” category may be utilised but with caution. During these marches, soldiers were taxed between 65% and 75% of VO2 max. The results of this study clearly demonstrate that the interplay between speed and load needs to be adjusted when determining “ideal” combinations for specific military demands. Essentially, if speed is of the essence then load must be reduced, and if heavy loads need to be transported then speed must be reduced.

O trabalho teve como objetivo analisar a associação entre a deambulação e a duração da fase ativa do trabalho de parto e avaliar o nível de dor da parturiente durante toda esta fase. 0bjetivos específicos: 1)identificar quantitativamente o trajeto percorrido durante a deambulação de parturientes no trabalho de parto; 2) verificar a presença de correlação entre a distância deambulada e a duração da fase ativa do trabalho de parto; 3) verificar a presença de correlação entre a distância deambulada a cada hora do trabalho de parto com a duração do mesmo; 4) avaliar o nível de dor da parturiente durante toda a fase ativa do trabalho de parto. Metodologia: estudo analítico de intervenção do tipo quase experimental. Fizeram parte do estudo 80 parturiente primíparas, admitidas em trabalho de parto espontâneo, no início da fase ativa (4 a 5 cm de dilatação cervical), que foram monitoradas em toda a fase ativa do trabalho de parto, ou seja, até completar 10 cm de dilatação cervical e encaminhamento para a sala de parto. Instrumentos de coleta de dados: podômetro para medir a distância percorrida em metros, Escala Visual Numérica de dor (EVN), formulário para o registro de dados. Análise dos dados: distribuição de freqüência, teste de Correlação paramétrico de Pearson, teste de Correlação não paramétrico de Spearman e teste de Regressão Linear Simples. Resultados: as participantes percorreram uma distância média de 1624metros, 63,09% da fase ativa do trabalho de parto e em um tempo médio de 5 horas. Verificou-se que a quantidade deambulada durante as três primeiras horas da fase ativa está associada a um encurtamento do trabalho de parto, sendo que a cada 100 metros percorridos ocorreu uma diminuição de 22 minutos na primeira hora, 10 minutos na segunda hora e 6 minutos na terceira hora. Os dados apontam que a indicação do uso de ocitócito e ruptura da bolsa amniótica não influenciaram na duração da fase ativa do trabalho de parto. Quanto aos escores de dor, verificou-se que a pontuação dos mesmos aumentou à medida que a dilatação cervical avançava. Foi encontrada uma correlação positiva apenas aos 5 cm de dilatação, ou seja, quanto maior os trajetos percorridos maiores foram os escores de dor pontuados pelas parturientes. / This study aimed to analyze the association between walking and the duration of the active phase of labor and obstetric results, with the following specific objectives: 1) identify the distance women walked during labor; 2) verify whether the distance walked is correlated with the duration of the active phase of labor; 3) verify whether the distance walked during each hour of labor is correlated with its duration; 4) evaluate the parturient women’s pain level throughout the active phase of labor. Methodology: We realized an analytic, quasi-experimental intervention study. Study participants were 80 primiparous parturient women, who were admitted during spontaneous labor, at the start of the active phase (4 to 5cm of cervical dilatation) and were monitored throughout the entire active phase of labor, that is, until they reached 10cm of cervical dilatation and were sent to the delivery room. Data collection instruments: podometer to measure the distance walked in meters, numerical visual pain scale, and form for data registration. Data analysis: frequency distribution, Pearson’s parametric correlation test, Spearman’s non-parametric correlation test and Simple Linear Regression test. Results: the parturient women walked an average distance of 1624 meters, 63.09% of the active phase of labor and during an average time of 5 hours. We observed that the distance walked during the first three hours of the active phase is associated with a shorter labor time. For every 100 meters walked, duration decreased by 22 minutes during the first hour, by 10 minutes during the second hour and by 6 minutes during the third hour. Data revealed that the indication of oxytocic agents and the rupture of the amniotic bag did not influence the duration of the active phase of labor. Pain scores increase along with the advance in cervical dilatation. However, we only found a significant positive correlation when 5cm of dilatation had been reached, that is, the more distance the participants walked, the higher the pain scores they reached.

[Conclusions] l) The two forms of human locomotion, walking and running, are distinctly different and in evaluating these gait patterns consideration must be given to this fact. 2) The impression created by the energy cost curves, that there is a single locomotor interface for both walking and running is a false one . There are two distinctly different locomotor interfaces, the walk-to-run interface and the run-to-walk interface. The former appears to correspond with the "metabolic intersection point" and therefore has some metabolic significance. The latter appears to be merely an "overshoot" of the walk-to-run interface and presently has no apparent metabolic significance. 3) Because the walk-to-run interface speed corresponds with the intersection point of the energy cost curves, physiological responses to walking and running at this speed do not differ significantly. However, cadence and stride length patterns for these two locomotor patterns are distinctly different at this point. 4) The identification of single physiological or kinematic factors during perceptions of exertion in any given situation is an extremely difficult if not impossible task. Perceived exertion should therefore be considered a multi-factorial concept and should be evaluated as such. 5) The use of relative speed as a technique for reducing inter-subject variability in physiological and kinematic factors is worthless unless diverse ranges in morphological linearity are a characteristic of one's subject pool

Background: Declines in gait velocity, stride length, cadence, and postural stability are common with advancing age and have further been linked to heightened fall risk and functional decline. Physical activity can slow or prevent such gait declines in older adults. In young adults, Nordic walking (NW) training has been shown to increase stride length and gait speed, yet has demonstrated inconsistent findings regarding joint loading, with reports of both increases and decreases in this respect. Further, research of this facet has very minimally been examined as it pertains to older adults. Purpose: The aim of the present study was to determine both the initial effect, and the prolonged effect following an 8-week intervention, of Nordic walking (NW) on older adult gait performance and postural alignment and stability. Methods: Gait and postural alignment and stability during NW and conventional walking were assessed and compared following an 8-week NW program (2x/week) in 12 healthy older adults (age: 68 ± 6.8 years; 8 female, 4 male). Participants performed six 5m walking trials, 3 with poles and 3 without, followed by two 6 Minute Walk Test (6MWT) trials, one with poles (WP) and the other without (NP). Gait characteristics and trunk measures in the sagittal and frontal planes were quantified using a 6 inertial sensor accelerometry system (APDM, Oregon, USA) as well as an eight camera 3-dimensional motion capture system (Vicon, Oxford, UK) with 2 force platforms (Kistler, Winterthur, Switzerland) embedded within. All variables were assessed using two-way repeated measures ANOVAs to compare NW to conventional walking and before and after the intervention. Results: When comparing walking WP to NP at initial pre-testing, significantly longer stride length, slower gait speed, and increased double support time were found to coincide with decreases in power generation and absorption at the hip and knee WP. However, following prolonged practice, a longer stride length, faster gait speed, and increased power generation at pre-swing at the hip and power absorption during loading and terminal swing about the knee were found WP post-intervention. Conclusions: An initial 8-week training period is necessary for novice NW in order to develop technique and to restore gait and postural alignment to more “normal” standards following training. Additionally, since the acquisition of the skill requires proper allocation of attention between two tasks: walking and pole manipulation, NW should be done so in a relatively safe environment, free of distraction and obstacles. Finally, with frail elderly, a longer acquisition period may be necessary since facilitation of movement must first occur.

Loss of mobility and independence directly affects the quality of life of many vulnerable individuals. To address this, researchers have developed wearable walking assist exoskeletons to aid users with their daily activities. While this technology has advanced tremendously in the past decade, current exoskeletons cause discomfort and injuries to the user, leading to device rejection. This research intends to develop a kinematically compatible knee joint suitable for exoskeletons. The proposed knee design can be adapted to accommodate an offset and optimize force delivery. This is achieved by ensuring that the mechanical and biological joint rotation axes are aligned and that the moment arm varies throughout flexion. Model simulations and mechanical testing of fabricated prototypes were achieved to analyze and validate the design. The results confirm the kinematic compatibility of the design and that the moment arm could be varied throughout flexion to achieve optimal and effective moment transfer.

OBJECTIVES:: Evaluate effects of a new off-the-shelf insert on frontal plane foot biomechanics and compare effectiveness of the new and an existing off-the-shelf insert and a motion-control shoe in neutralizing frontal plane foot biomechanics. Design: Descriptive. Setting: Biomechanics laboratory. Participants: Fifteen uninjured subjects with a flexible flatfoot secondary to forefoot varus. Assessment of risk factors: Three-dimensional kinematic and kinetic data were collected as subjects walked and jogged at their self-selected speed while wearing a motion-control running shoe, the shoe with a new off-the-shelf insert, and the shoe with an existing off-the-shelf insert. Main outcome measures: Frontal plane kinematics and rearfoot kinetics were evaluated during stance. Statistical analysis was performed using a repeated measures analysis of variance and Student-Newman-Keuls post hoc tests (α ≤ 0.05). Results: The new insert and motion-control shoe placed the forefoot in a less-everted position than the existing off-the-shelf insert during walking. There were no differences in forefoot kinematics during jogging, nor were there differences in rearfoot motion during walking or jogging. The rearfoot eversion moment was significantly lower with the new off-the-shelf insert compared with the motion-control shoe and the existing insert during walking and jogging. Conclusions: A new off-the-shelf device is available that promotes more neutral frontal plane biomechanics, thus providing a theoretical rationale for using this device for injury prevention and treatment. The comparative biomechanical effectiveness of a motion-control shoe and the orthotic inserts may assist health care professionals in selecting a device to correct the flatfoot structure.

Exoskeletons for rehabilitation commonly focus on gait training, despite the variety of human movements and functional assistance needed. Cable-driven exoskeletons have an advantage in addressing a variety of movements by being non-restrictive in their design. Additionally, these devices do not require complex mechanical joints to apply forces on the user or hinder the user's mobility. This accommodation of movement makes these cable-driven architectures more suitable for everyday movement. However, these flexible cable-driven exoskeletons often actuate a reduced number of actuated degrees-of-freedom to simplify their mechanical complexity. There is a need to design flexible and low-profile cable-driven exoskeletons to accommodate the movement of the user and be more flexible in their ability to actuate them. This thesis presents cable-driven exoskeleton designs that are used during walking and or squatting. These exoskeletons can be reconfigured to apply forces that are appropriate for these functional tasks. The three designs presented in this thesis are non-restrictive cable-driven designs that add minimal weight to the user. The first design shown is the cable-driven active leg exoskeleton previously developed by the Robotics and Rehabilitation Laboratory (C-ALEX, 10kg). The second and third designs are novel cable-driven architectures: (i) the modular C-ALEX (mC-ALEX, 3kg) and (ii) the soft C-ALEX (SC-ALEX, <1kg). A preliminary evaluation of the latter two devices was performed, and the results of these studies are presented to better understand the limitations and abilities of each design. The functionalities added to the latter two designs include the ability to reconfigure the robot's cable routing and attachment geometry, allowing the devices to apply torques through cables in the non-sagittal plane. These features will enable the robot to assist in tasks other than gait while still using the original C-ALEX design methods. Another feature added to the exoskeleton controller is to allow visual feedback through an Augmented Reality headset (the HoloLens) to incorporate visual feedback during tasks better. This feature is currently missing from the rehabilitation field using exoskeletons. The effects of using the C-ALEX with post-stroke participants were carried out to ascertain the efficacy of using a cable-driven system for gait adaptations in persons with gait impairments and compare their effectiveness against rigid-linked exoskeletons. The C-ALEX was assessed to induce a change in the walking patterns of ten post-stroke participants using a single-session training protocol. The ability of C-ALEX to accurately provide forces and torques in the desired directions was also evaluated to compare its design performance to traditional rigid-link designs. Participants were able to reach 91% ± 12% of their target step length and 89% ± 13 % of their target step height. The achieved step parameters differed significantly from participant baselines (p <0.05). To quantify the performance, the forces in each cable's out-of-the-plane movements were evaluated relative to the in-plane desired cable tension magnitudes. This corresponded to an error of under 2Nm in the desired controlled joint torques. This error magnitude is low compared to the system command torques and typical adult biological torques during walking (2-4%). These results point to the utility of using non-restrictive cable-driven architectures in gait retraining, in which future focus can be on rehabilitating gait pathologies seen in stroke survivors. Visual and force feedback are common elements in rehabilitation robotics, but visual feedback is difficult to provide in over-ground mobile exoskeleton systems. A preliminary study was carried out to assess the effects of providing force-only, force and visual, or visual-only feedback to three independent groups, each containing 8 participants. The groups showed an increase in normalized step height, (force and visual: 1.10 ± .13, force-only: 1.03 ± .23 visual-only: 1.61 ± .52) and decreased normalized trajectory tracking error (force and visual: 42.8% ± 23.4%, force: 47.6% ± 18.4% , visual-only: 114.2% ± 60.0%). Visual normalized step height differed significantly from force and visual and force-only normalized step height (p<0.005). Lap-wise normalized tracking error differed significantly ($p < 0.005$) within participants. The mC-ALEX and the HoloLens were used to test the effectiveness of robot force feedback compared to visual feedback with a squat task. The squat task aimed to have the user reach targets of 25%, 75%, and 125% of baseline squats depths through each feedback modality. The kinematic and foot loading effects were considered to establish the differences in user behavior when receiving both types of feedback. The results show that visual feedback has lower errors from targets with similar lower variability in user performance. The force feedback changed joint flexion profiles without changing foot loading biomechanics. When looking at the sessions in sequence, both feedback modalities reduced depth error magnitudes further along with the sessions time-wise. This is the first study where augmented in-field-of-view visual feedback and robotic feedback are used with the aim of changing the kinematics of a squatting task. Overall, this thesis contributes to expanding the capabilities of cable-driven exoskeletons in lower limb rehabilitative tasks. Three designs are evaluated to understand their on-user performance, with the latter two devices being novel designs. The devices are used in protocols that include visual feedback to ascertain their effects on movement adaptation through the two feedback modalities.

Many research projects have been conducted to compare standing text entry with nomadic text entry. Other research projects have compared the input types of touchscreen and physical keyboards while texting. There is few literature that compares the two inputs types during a standing and nomadic text entry. This research was conducted to investigate the differences in error rate and characters per minute for both input types during both text entry conditions. To investigate these differences two devices were used, the iPhone 4 and the Blackberry Curve 9350, to type a phrase during both a standing and walking condition. Both characters per minute and error rate were analyzed. The investigation showed that there were no significant difference in error rate, but there was a significant difference in characters per minute. The touchscreen keyboard performed better in terms of characters per minutes and arguably performed better in accuracy.

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