Role In Walking Research Articles

Natural history of late-onset GM2 gangliosidosis: Four years of data collected at NTSAD annual conferences

Intramuscular fat infiltration is a dynamic process, in response to exercise and muscle health, which can be quantified by estimating fat fraction (FF) from Dixon MRI. Healthy hip abductor muscles are a good indicator of a healthy hip and an active lifestyle as they have a fundamental role in walking. The automated measurement of the abductors' FF requires the challenging task of segmenting them. We aimed to design, develop and evaluate a multi-atlas based method for automated measurement of fat fraction in the main hip abductor muscles: gluteus maximus (GMAX), gluteus medius (GMED), gluteus minimus (GMIN) and tensor fasciae latae (TFL).We collected and manually segmented Dixon MR images of 10 healthy individuals and 7 patients who underwent MRI for hip problems. Twelve of them were selected to build an atlas library used to implement the automated multi-atlas segmentation method. We compared the FF in the hip abductor muscles for the automated and manual segmentations for both healthy and patients groups. Measures of average and spread were reported for FF for both methods. We used the root mean square error (RMSE) to quantify the method accuracy. A linear regression model was used to explain the relationship between FF for automated and manual segmentations.The automated median (IQR) FF was 20.0(16.0–26.4) %, 14.3(10.9–16.5) %, 15.5(13.9–18.6) % and 16.2(13.5–25.6) % for GMAX, GMED, GMIN and TFL respectively, with a FF RMSE of 1.6%, 0.8%, 2.1%, 2.7%. A strong linear correlation (R2 = 0.93, p < .001, m = 0.99) was found between the FF from automated and manual segmentations. The mean FF was higher in patients than in healthy subjects.The automated measurement of FF of hip abductor muscles from Dixon MRI had good agreement with FF measurements from manually segmented images. The method was accurate for both healthy and patients groups.

Background. The diverse experience of artistic culture, refl ected in the established system of genres, appears in a new light from the standpoint of modernity as experts

Background. The diverse experience of artistic culture, refl ected in the established system of genres, appears in a new light from the standpoint of modernity as experts

Gait-Assist Wearable Robot Using Interactive Rhythmic Stimulation to the Upper Limbs.

Many power-assist wearable exoskeletons have been developed to provide walking support and gait rehabilitation for elderly subjects and gait-disorder patients. Most designers have focused on a direct power-assist to the wearer's lower limbs. However, gait is a coordinated rhythmic movement of four limbs controlled intrinsically by central pattern generators, with the upper limbs playing an important role in walking. Maintaining a normal gait can become difficult as a person ages, because of decreases in limb coordination, stride length, and gait speed. It is known that coordination mechanisms can be governed by the principle of mutual entrainment, in which synchronization develops through the interaction between nonlinear phase oscillators in biological systems. This principle led us to hypothesize that interactive rhythmic stimulation to upper-limb movements might compensate for the age-related decline in coordination, thereby improving the gait in the elderly. To investigate this hypothesis, we developed a gait-assist wearable exoskeleton that employs interactive rhythmic stimulation to the upper limbs. In particular, we investigated the effects on spatial (i.e., hip-swing amplitude) and temporal (i.e., hip-swing period) gait parameters by conducting walking experiments with 12 healthy elderly subjects under one control condition and five upper-limb-assist conditions, where the output motor torque was applied at five different upper-limb swing positions. The results showed a statistically significant increase in the mean hip-swing amplitude, with a mean increment of about 7% between the control and upper-limb-assist conditions. They also showed a statistically significant decrease in the mean hip-swing period, with a mean decrement of about 2.3% between the control and one of the upper-limb-assist conditions. Although the increase in the hip-swing amplitude and the decrease in the hip-swing period were both small, the results indicate the possibility that interactive rhythmic stimulation to the upper limbs might have a positive effect on the gait of the elderly.

Multi-modal neuroimaging of dual-task walking: Structural MRI and fNIRS analysis reveals prefrontal grey matter volume moderation of brain activation in older adults

It has been well established over the last two decades that walking is not merely an automatic, motoric activity; it also utilizes executive function circuits, which play an increasingly important role in walking for older people and those with mobility and cognitive deficits. Dual-task walking, such as walking while performing a cognitive task, is a necessary skill for everyday functioning, and has been shown to activate prefrontal lobe areas in healthy older people. Another well-established point in healthy aging is the loss of grey matter, and in particular loss of frontal lobe grey matter volume. However, the relationship between increased frontal lobe activity during dual-task walking and loss of frontal grey matter in healthy aging remains unknown.In the current study, we combined oxygenated hemoglobin (HbO2) data from functional near-infrared spectroscopy (fNIRS), taken during dual-task walking, with structural MRI volumetrics in a cohort of healthy older subjects to identify this relationship. We studied fifty-five relatively healthy, older participants (≥65 years) during two separate sessions: fNIRS to measure HbO2 changes between single-task (i.e., normal walking) and dual-task walking-while-talking, and high-resolution, structural MRI to measure frontal lobe grey matter volumes. Linear mixed effects modeling was utilized to determine the moderation effect of grey matter volume on the change in prefrontal oxygenated hemoglobin between the two walking tasks, while controlling for covariates including task performance. We found a highly significant interaction effect between frontal grey matter volume and task on HbO2 levels (p < 0.0001). Specifically, increased HbO2 levels during dual-task compared to single-task walking were associated with reduced frontal grey matter volume. Regional analysis identified bilateral superior and rostral middle gyri as the primary areas driving these results. The findings provide support for the concept of neural inefficiency: in the absence of behavioral gains, grey matter loss in relatively healthy, older individuals leads to over-activation of frontal lobe during a cognitively demanding walking task with established clinical and predictive utility.

FACILITATING FACTORS OF WALKING BASED ON THE EXPERIENCES OF WOMEN WITH TYPE 2 DIABETES: A QUALITATIVE STUDY

Background: Diabetes is one of the major health challenges facing the world and leading to many complications. Physical activity, such as walking is one of the approaches to reduce the symptoms and complications of the disease. The purpose of this study was to investigate the experiences of women with type 2 diabetes with respect to facilitating factors of walking . Methods: This qualitative study using directed content analysis was conducted by using semi-structured individual interviews and group interviews with 17 women aged 30-60 year with type 2 diabetes, selected by purposive sampling, at the Diabetes Center of Kerman in 2017. Results: The mean age of participants was 46.94 ± 8.6 years. Eight subcategories (peace of mind, diverse urban green spaces, awareness and understanding of the benefits of walking, individual responsibility, security, family support, equipment and facilities for walking) were drawn as facilitators of walking in diabetic women in this study. Conclusion: According to the results of this study and the role of walking in reducing and controlling the physical and psychological symptoms of diabetes, it is possible to provide a suitable platform to do walking and develop proper culture by identifying its facilitators.

Design of Vector Field for Different Subphases of Gait and Regeneration of Gait Pattern

In this paper, we have designed the vector fields (VFs) for all the six joints (hip, knee, and ankle) of a bipedal walking model. The bipedal gait is the manifestation of temporal changes in the six joints angles, two each for hip, knee, and ankle values and it is a combination of seven different discrete subphases. Developing the correct joint trajectories for all the six joints was difficult from a purely mechanics-based model due to its inherent complexities. To get the correct and exact joint trajectories, it is very essential for a modern bipedal robot to walk stably. By designing the VF correctly, we are able to get the stable joint trajectory ranges and able to reproduce angle ranges from theses designed VFs. This is purely a data driven computational modeling approach, which is based on the hypothesis that morphologically similar structure (human-robot) can adopt similar gait patterns. To validate the correctness of the design, we have applied all the possible combination of joint trajectories to HOAP-2 bipedal robot, which could walk successfully maintaining its stability. The VF provides joint trajectories for a particular joint. The results show that our data driven computational model is able to provide the correct joints angle ranges, which are stable. Note to Practitioners —In this research, we have developed the vector field (VF) for each joint (hip, knee, and ankle) of a biped, which plays an important role in walking. The idea is noble and based on data driven computational model. The generated trajectories are applied on HOAP-2 bipedal humanoid robot and compare the two joint trajectories from VF with HOAP-2 model and hybrid automata model.

FLOW: An European Project to Address Congestion and Give Walking and Cycling Equal Footing in Transport Modelling ( breakout presentation )

The mission of the FLOW project is to put walking and cycling on an equal footing with motorised modes by developing a user-friendly methodology to assess the effectiveness of walking and cycling measures in addressing urban road congestion. FLOW is the first project explicitly linking walking and cycling with congestion reduction. The project takes a trans-disciplinary approach to congestion reduction, and aims to create and implement a new state-of-the-art by integrating the FLOW methodology and congestion assessment tools into the current standard transport impact analysis process. Its objectives are: 1) to define the role of walking and (safe) cycling in congestion reduction; 2) to develop and apply tools for assessing the congestion-busting impacts of various walking and cycling measures; 3) to demonstrate and assess the congestion reduction impact of various walking and cycling measures; 4) to actively support take-up of congestion reducing measures by public administration; 5) to increase awareness of the congestion reduction potential of walking and cycling; 6) to foster the market for new walking and cycling products and services for congestion reduction, and; 7) to communicate congestion reduction facts of walking and cycling. FLOW targets three main stakeholder groups: cities, businesses and decision-makers - with the aim of shifting the way these groups think about and act on the potential for non-motorised transport to reduce congestion. FLOW partner cities will pilot the assessment tools that look at the congestion impact of walking and cycling measures as well as improved transport modelling simulation tools. These will be used to develop implementation scenarios and action plans to add or upscale cycling and walking measures shown to reduce congestion. This presentation will provide an overview of the project and the resources and tools being developed and delivered and the results that are starting to emerge from this innovative work.

Sustainable urban transport – the role of walking and cycling

Walking and cycling are both underutilised transport modes in most UK urban areas. Among other benefits, they do not directly produce pollutants at point of use, they generate limited noise and they require less space than motor vehicles. Walking and cycling importantly provide a good source of regular exercise. The link between active travel and health has been studied extensively and is generally accepted. However, most research focuses on walking and cycling for private transport, either for leisure or for more functional reasons. The use of walking and cycling as a means of freight transport appears vastly underresearched, and the potential is unclear. This overview paper argues that it is possible to put in place packages of measures that can significantly improve both levels of walking and cycling. This may mean fundamentally changing the existing power relationships that exist between different transport modes, provision of a greater proportion of funds towards active modes of transport and consideration of novel ways of financing to encourage change.

Dual-task and electrophysiological markers of executive cognitive processing in older adult gait and fall-risk.

The role of cognition is becoming increasingly central to our understanding of the complexity of walking gait. In particular, higher-level executive functions are suggested to play a key role in gait and fall-risk, but the specific underlying neurocognitive processes remain unclear. Here, we report two experiments which investigated the cognitive and neural processes underlying older adult gait and falls. Experiment 1 employed a dual-task (DT) paradigm in young and older adults, to assess the relative effects of higher-level executive function tasks (n-Back, Serial Subtraction and visuo-spatial Clock task) in comparison to non-executive distracter tasks (motor response task and alphabet recitation) on gait. All DTs elicited changes in gait for both young and older adults, relative to baseline walking. Significantly greater DT costs were observed for the executive tasks in the older adult group. Experiment 2 compared normal walking gait, seated cognitive performances and concurrent event-related brain potentials (ERPs) in healthy young and older adults, to older adult fallers. No significant differences in cognitive performances were found between fallers and non-fallers. However, an initial late-positivity, considered a potential early P3a, was evident on the Stroop task for older non-fallers, which was notably absent in older fallers. We argue that executive control functions play a prominent role in walking and gait, but the use of neurocognitive processes as a predictor of fall-risk needs further investigation.

An interpretive phenomenological study: podolinguistics, sportsmen and masculinity

This empirical piece of 2013 Doctoral research, considers the role of podolinguistics and its relationship to masculinity and sport. Podolinguistics or podopsychosomatics a term originally introduced by Rossi (1977) is said to be the language of feet and shoes. Taking this concept a step further, podolinguistics is reading the transmitted signifiers that are understood through wearing different types of footwear, in this instance. In this body of work, the author forms a podolinguistic theoretical relationship to men in sporting environments, with a particular focus on reading into the signifiers of masculinity, utilising an Interpretive Phenomenology and a Masculinity Theory approach. Ethical approval was gained form the University of East London. Eight sportsmen (four heterosexual and four homosexual) were recruited into the study, from a range of different sporting disciplines. Each participant took part in a one-hour semi-structured interview, where insights into masculinity and sport were explored. The structure of these interviews took into account the life histories of the participant. The interviews were transcribed for analysis. An Interpretive Phenomenological Approach (Smith, Flowers and Larkin, 2009) was utilised to analyse the data, appreciating the phenomenological, the hermeneutic and idiographic qualities of the interview transcripts, resulting in the development of themes. The results indicated a complex relationship of understanding footwear and podolinguistics in the sporting setting. This relationship includes the realisation of three categories of footwear in sport that shape masculine bonds between men. These categories include, sporting-footwear, social-sporting-footwear and general footwear. Developing this categorisation further, it became apparent that colour of sporting-footwear and social-sporting footwear, was the most fundamental/influential feature in shaping/understanding masculinity through a podolinguistic signifying relationship. Finally, the results also indicated that the foot and shoe was not the only feature to be included in the definition of podolinguistics. This empirical piece of research complemented Rossi’s (1977) definition, by adding the role of ‘walking’ to the 1977 understanding of podolinguistics. It was found that the role of walking, and modelling a heterosexual stance of walking, was interpreted as masculine/heterosexual. This piece of research puts the previously ignored concept of podolinguistics back into the academic frame. In this example, by focussing on masculinity and podolinguistics in sport, we are able to see how a new awareness of this relationship, shapes men’s understandings of their lives and masculinity though footwear. It gives us the foundation in podiatry, to step back and reconsider the psychosocial role of footwear, feet and walking in shaping podolinguistics, as a new academic discipline for debate. Smith, J.A., Flowers, P. and Larkin, M. (2009) Interpretive Phenomenological Analysis: Theory, Method and Research. London: Sage Rossi, W.A. (1977)The Sex Life of the Foot and Shoe. London: The Camelot Press Ltd.

Impact of orthoses on imagined and actual walking

Background We know that duration between an actual movement and an imaginary one is similar [1]. We wondered if wearing insoles has an impact on those timings, and particularly if different kinds of insoles have a different impact. We do know that walking changes the respond of motor commands [2]. Feet have a real role in walking as we know. Wearing insoles have an effect on the biomechanics of the entire body [3]. Two kinds of corrections exist. Biomechanical insoles correct with higher stimulations than mediation postural ones. The remediation uses different ways of informations regarding the insoles and so is the effective response. To compare we have made for each patient a pair of mediation postural foot orthoses (FosMP) and a pair of biomechanical foot orthoses (FosBM). 10 patients have walked actual 30 feet on physical practice (PP) and imagined walking, mental practice (MP). We have tested them in tree conditions: without insoles (control Ct), with FosMP and with FosBM. We have looked the FosMP/BM modifications through platform’s parameters: speed, speed’s variation and area of center of force; bio-clinical evaluation: posturodynamic test [4] and visual-analogic-scale to evaluated their comfort. All parameters were recorded before (Pre) and after (Post) PP and MP.

A study of human physiological response to intensity of somatosensory stimulation applied to the ankle tendon

The present study was conducted to observe human physiological response through EEG to intensity of somatosensory stimulation applied on the tibialis anterior and Achilles tendons. In order to investigate the relation between physiological response and somatosensory stimulation, two hypotheses were established. First, different human body reactions may be induced depending on the location of the incoming somatosensory stimulation; second, somatosensory stimulation even at sub-threshold levels could significantly affect the human body. The experiment was conducted with the somatosensory stimulation system and EEG system, seven male adults were involved. The three kinds of somatosensory stimulation (sub-threshold, threshold, supra-threshold) was uesd, these stimulation was applied to the Achilles tendon and the tibialis anterior tendon of the subjects, and their brain waves were measured. According to the results of experiments, the brain response to somatosensory stimulation to the ankle tendons and the structures that play an important role in walking were shown to be different according to the inflow location of the somatosensory stimulation. And the brain response to somatosensory stimulation to the tibialis anterior tendon and Achilles tendon appeared similar regardless of the stimulation intensity.

The sound of locative media

This article develops an alternative perspective to the visual bias in locative media discourses by focusing on the role of sound in locative media and related discussions. This sonic perspective allows us to understand the temporal, situated and embodied aspects of locative media. Informed by debates from sound studies and mobile media studies, a locative smart phone application where users experience specific sounds depending on their locations, is discussed. The concept of ‘Placed Sounds’ is introduced for a more detailed analysis of locative sound experiences. A framework for analysis is developed to discuss how locative sound engages with the auditory aspects of our spatial perception, how immersion operates for locative media and sound, and also to consider the role of situated experience, the role of walking as remixing, and how agency and exclusion operate in locative sound. This framework explains how walking operates in terms of interacting with locative media, and how we experience being immersed in physical and media contexts at once via sound.

The Sensory Experiencing of Urban Design: The Role of Walking and Perceptual Memory

Experience is conceptualised in both academic and policy circles as a more-or-less direct effect of the design of the built environment. Drawing on findings from a research project that investigated people’s everyday experiences of designed urban environments in two UK towns, this paper suggests at least two reasons why sensory encounters between individuals and built environments cannot in fact be understood entirely as a consequence of the design features of those environments. Drawing from empirical analysis based on surveys, ethnographic ‘walk-alongs’ and photo-elicitation interviews, we argue that distinct senses of place do depend on the sensory experiencing of built environments. However, that experiencing is significantly mediated in two ways. First, it is mediated by bodily mobility: in particular, the walking practices specific to a particular built environment. Secondly, sensory experiences are intimately intertwined with perceptual memories that mediate the present moment of experience in various ways: by multiplying, judging and dulling the sensory encounter. In conclusion, it is argued that work on sensory urban experiencing needs to address more fully the diversity and paradoxes produced by different forms of mobility through, and perceptual memories of, built environments.

The Role of Walking and Cycling in Advancing Healthy and Sustainable Urban Areas

At the heart of much new planning policy directed towards creating healthy and sustainably urban areas are two modes of transport – walking and cycling. With contributions from the UK, US, Australia and mainland Europe, this issue focuses on walking and cycling from a broad perspective. It considers what we need to know about these ‘active transport’ modes to understand their importance; the evidence for what works and how much change might be possible and over what timescales; and the benefi ts from such change.

Elderly Oarsmen Have Larger Major Psoas Muscle Mass

Knee extensor muscle (KE) and major psoas muscle (MP) of trunk play a decisive role in walking, stair ascent/descent, and so on in humans. Particularly, it is important for elderly people to prevent the weakness of these muscles to enhance quality of life. Rowing consists of rhythmical muscle contractions in both the lower and upper body, and demands a high aerobic capacity (Secher et al., 1983). Early study suggested that rowing prevents the wasting of leg extensor muscle in elderly men (Yoshiga et al., 2002), whereas no information is available on MP in elderly rowers. PURPOSE: For the purpose of examining the preventive effect of rowing on MP mass, in the present study, we compared MP mass and trunk flexion force in elderly male rowers with age-matched untrained men. METHODS: Participants were 22 elderly rowing trained men (RT; age: 67.5±2.5 yrs, height: 172.0±4.8 cm, body mass: 69.4±7.0 kg, Fat Free Mass (FFM): 55.9± 3.7 kg, VO2peak:37.6±6.3 mL/kg/min, mean±SD) and 19 untrained elderly men(UT:66.0±2.5 yrs, 164.7±4.2 cm, 63.4±8.1 kg, 49.7 ± 4.8 kg, 28.7 ± 5.7 mL/kg/min). Muscle cross-sectional area (CSA) was measured on MP and KE by magnetic resonance imaging, and bilateral leg extension power and trunk flexion force were measured. RESULTS: The CSAs of MP and KE in RT were significantly larger by 45% and 15% than those in UT, respectively (RT vs UT; MP: 30.2±5.2 vs 20.9±4.3 cm2, p < 0.001. KE: 120.7±15.6 vs 105.1±17.7 cm2, p < 0.01). MP CSA per FFM of RT was 29% higher than that of UT (RT: 0.54±0.09 vs UT: 0.42±0.08 cm2/kgFFM, p<0.001), while there was no significant difference between the two groups in KE CSA per FFM (RT: 2.15±0.2 vs UT: 2.11±0.25 cm2/kgFFM). Compared with UT, RT had higher leg extension power (W, W/cm2CSA) by 42%, 23% (RT vs UT; 1256±247 vs 887±219 W, 10.4±1.5 vs 8.4±1.6 W/cm2CSA, p<0.001, respectively). Trunk flexion force in RT was also 44% higher than that in UT (RT: 421±56 vs UT: 292±57 N, p<0.001), but in trunk force expressed by N/cm2CSA, no significant difference was observed between the two groups (RT: 14.2±2.1 vs UT: 14.3±3.0 N/cm2CSA). CONCLUSIONS: These results provide possibility that rowing exercise prevents the wasting and weakness of major psoas muscle in elderly men.

Calcaneal fractures in occupants involved in severe frontal motor vehicle crashes

The calcaneous is the largest tarsal bone in the foot and plays an important role in walking and running. Motor vehicle crashes and falls from elevation have been associated with calcaneal fractures. Although not life-threatening, these injuries may result in permanent disability. This study used the Crash Injury Research and Engineering Network (CIREN) database to describe calcaneal fractures and concomitant lower extremity skeletal injury patterns for occupants involved in motor vehicle crashes. Sixty-three drivers and 7 front row passengers with calcaneal fractures were identified in the CIREN database during 1997–2005. Almost all these occupants were involved in severe (based on the delta V and vehicle crush) frontal or off-set frontal crashes with toe pan intrusion. Eighty-four percent of the calcaneal fractures were intra-articular or partially articular. Overall, 93% of occupants also had injury to other body regions with 84% having other lower extremity fractures. One year after the crash, most occupants had not returned to their prior level of physical functioning. Surgically managing patients with calcaneal fractures for an optimal outcome remains a challenge for orthopedic surgeons. Because lower extremity injuries, including calcaneal fractures, may cause permanent disability, it is important to prevent these injuries through structural improvements in motor vehicle design.

The role of vertebral column muscles in level versus upslope treadmill walking—An electromyographic and kinematic study

To gain insight into the neural mechanisms controlling vertebral column movement and its role in walking, we performed kinematic and electromyographic (EMG) studies on cats during level and upslope treadmill walking. Kinematic data of the limbs and vertebral column were obtained with a high-speed camera synchronized with EMG recordings from levels T10, L1, and L5 of m. longissimus dorsi (Long). During a single-step cycle at all upslope angles, vertebral movement in the lateral (left–right), cranial–caudal (forward–backward), and dorsal–ventral (upward–downward) directions was observed. Lateral movements were produced by forelimb take-off and hindlimb landing, and forward and upward movements were produced by hindlimb extension. During the single-step cycle, each of the three epaxial muscles, m. multifidus, m. iliocostalis, and Long, showed two bilateral EMG bursts. The onset of the EMG bursts coincided with the left–right movements, suggesting that epaxial muscle activity depresses lateral movement. The termination of the EMG bursts correlated with the forward and downward phase of the step cycle, suggesting that contraction of the epaxial muscles produces forward and downward movements. EMG bursts of the epaxial muscles increase the stiffness and produce inwardly movements to decrease the lateral movements of the vertebral column and the termination of EMG bursts control the movements into cranial and ventral direction of the vertebral column. The results suggest that the rhythmic EMG bursts in the epaxial muscles are produced by pattern generators, and the timing of EMG bursts among the different levels of the epaxial muscles are altered by walking condition input via peripheral afferents and descending pathways.

A kinematic study of front legs' movements in walking Protura (Insecta)

AbstractHigh‐speed cine film of walking Protura shows that a) the forward projected legs 1 move almost parallel to the body; and b) their point of contact with the ground is only in front of the coxal articulation. The average stride length of legs 1 (0.05 mm) measures one‐third that of legs 2 and legs 3 (0.15 mm). These features indicate a relatively small contribution of the front legs in supporting and propelling the animal, which is accomplished by a pulling rather than a pushing action. On a horizontal rough surface of moist plaster, the animal moves by three fashions: a) it holds up the front legs and walks with the middle and rear legs, b) it places occasionally one or both front legs on the ground while walking with the middle and rear legs, and c) it uses all six legs in walking. In the latter case the average promotion duration of legs 1 (0.29 s) is twice that of legs 2 and 3 (0.15 s each), whereas the average remotion duration of legs 1 (0.08 s) is one‐half that of legs 2 and 3 (0.17 s). In addition, the movements of legs 1 are not coordinated with the other two pairs in the typical hexapode stepping pattern. Instead, they are used independently with a tendency to alternating up and down movements. These specializations of legs 1 reflect an exploratory role in walking. On a horizontal slippery surface of transparent paper, the animal walks exclusively with six legs. In all legs, the duration of the remotion period increases as the time elapses in a series of walks. In legs 2 and 3 the remotion duration is longer than that of promotion throughout the experiment, but in legs 1 it changes from shorter to longer. Timing of the front legs' movements does not fit in the hexapode rhythm. Legs 1 are both simultaneously and alternatingly used, thus playing a part in propelling and balancing the body.

The external sensory morphology of the legs and hairplate system of femaleTrichogramma minutumRiley (Hymenoptera: Trichogrammatidae)

This work continues a comprehensive description of the external sensory morphology of the parasitoid waspTrichogramma minutum. All sensilla and associated structures identified by electron microscopy are described. In addition, this study also includes the hairplates associated with the antennae and neck region. The majority of sensilla appear to be mechanosensory, and are either trichoid or campaniform in structure. Large, socketed setae (10–50 μm long) are found on all leg segments, but vary considerably in body size and shape, depending upon location. On the tibial and tarsal segments of the pro- and metathoracic legs some of the larger hairs have been modified to form antennal and wing combs. On both the meso- and metathoracic legs a distal tibial seta is greatly enlarged and functions as a socketed spur. The sensilla that compose the hairplates are relatively short (1–3 μm) and differ in socket morphology from the longer setae located elsewhere on the body surface. Hairplates occur on the dorsal surface of the trochanter at the coxatrochanteral joint, on the distal portion of the coxae, around the neck on the dorsal and ventral surfaces of the episternum, and the opening of the postocciput. The most complex arrangement of hairplates surrounds the distal portion of the scape, and comprises four separate groups of hairs. Hairplates are also located on the dorsal and lateral surfaces of the proximal end of the pedicellus. Nine to eleven campaniform sensilla are located on the trochanter of each leg. The proximal subdivision of the femur is equipped with six sensilla grouped together on the ventral surface. Three to five campaniform sensilla are clustered on the dorsal surface of the distal end of the tibia of each leg, and a single pair of sensilla is located at the distal end of the first tarsomere. All the leg campaniform sensilla are elliptical, and 1.5–2.5 μm long. The number, position and morphology of the sensilla was consistent between individuals. The structure and function of these sensory structures are discussed in relation to their role in walking, proprioceptive control of posture, and gravity detection. The scaling of sensilla to body size and homologies with larger insects are also examined, and the possible role of these structures in the detection and measurement of host curvature is considered.