Effects of strength, flexibility and moderate intensity cardiovascular exercise on measures of fitness in sedentary women

The maintenance of functional physical fitness across the lifespan depends upon the presence or absence of disease, injury, and the level of habitual physical activity. The prevalence of sedentariness rises with increasing age culminating in 31% of elderly women being classified as leading a sedentary lifestyle. Exercise prescription that involves easily accomplished physical activity may result in the maintenance of mobility into old age through a reduction in the risk of premature death and disablement from cardiovascular disease and a reduction in the risk of falls and injuries from falls. It may be that short bouts of physical activity are more appealing to the sedentary and to those in full time employment than longer bouts, and it may be that short bouts of exercise, performed three times per day, can improve physical fitness. The purpose of this study was therefore to examine the problem: Does exercise session duration, initial cardiovascular fitness, and age group effect changes in functional physical fitness in sedentary women training for strength, flexibility and aerobic fitness? Twenty-three, sedentary women aged between 19 and 54 years who were employed at a major metropolitan hospital undertook six weeks of moderate intensity physical activity in one of two training groups. Participants were randomly allocated to either short duration (3 x 10 minute), or long duration (30 minute), exercise groups. The 3 x 10 minute group (n=13), participated in three, 10 minute sessions per day separated by at least 2 hours, 3 days per week. The 30 minute group (n=10), participated in three 30 minute sessions per week. The total amount of work was similar, with an average of 129 and 148 kcal training day for the 3 x 10 minute and 30 minute groups, respectively. The training program incorporated three walking and stair climbing courses for aerobic conditioning, a series of eleven static stretches for joint flexibility, and isotonic and isometric strength exercises for lower and upper body muscular strength. Measures of functional strength, functional flexibility and cardiovascular fitness were assessed prior to training, and immediately following the six week exercise program. A two way analysis of variance (Group x Time) was used to examine the effect of training and group on the dependent variables. The level of significance, 0.05 was adopted for all statistical tests. Mean hand grip strength showed for both groups no significant change over time for the 3 x 10 minute group (30.7kg to 31.7kg) and 30 minute group (30.2kg to 32.4kg). Leg strength showed a trend for improvement (p=0.098) in both the 3 x 10 minute and 30 minute training groups representing a 15% and 18% improvement, respectively. Combined right and left neck rotation significantly improved in the 3 x 10 minute group (82.8° to 92.0°) and 30 minute group (82.5° to 91.5°). Wrist flexion and extension improved significantly in 3 out of the 4 measurements. Left wrist flexion improved significantly by an average of 7.0% for the 3 x 10 minute and 4.9% for the 30 minute group. Right and left wrist extension improved significantly in the 3 x 10 minute and 30 minute training groups (5.9% and 6.8%, respectively). Hip and spine flexibility improved 3.4cm (35.2cm to 38.6cm) in the 3 x 10 minute group, and 6.6cm (37.4cm to 44.0cm) in the 30 minute group. There was a significant improvement in cardiovascular fitness for both groups representing a 22% improvement in the 3 x 10 minute group (27.2 to 33.2 ml kg min), and a 25% improvement in the 30 minute group (27.5 to 34.4 ml -kg min). No significant difference was shown in the degree of improvement in cardiovascular fitness over six weeks of training for subjects of either low or moderate initial aerobic fitness. Grip strength showed no significant changes over time for either the young-aged (19-35 years) or middle-aged (36-54 years) groups. Leg strength showed a trend for improvement (p=0.093) in the young-aged group (63.5kg to 71.9kg) and middle-aged group (69.3kg to 85.8kg). Neck rotation flexibility improved a similar amount in both the young and middle aged groups representing an improvement of 9.9° and 8.0° respectively. There was significant improvement in two of the four measures of wrist flexibility. Hip and spine flexibility was significantly greater in the young-aged group compared to the middle-aged group (38.5cm and 30.7cm, respectively). There was a significant improvement in hip and spine flexibility over the six week training program representing an increase in reach of 6.5cm for the young age group and 4.9cm for the older group. The middle-aged subjects had significantly lower cardiovascular fitness than their younger peers, scoring 22.8 and 30.7 ml -kg min, respectively. Cardiovascular fitness improved a similar amount in both age groups representing a significant improvement of 23.8% and 28.1% for the younger-aged and middle-aged subjects, respectively. The findings of this study suggest that short bouts of exercise may be equally as effective as longer bouts of exercise for improving the flexibility and cardiovascular components of functional physical fitness in sedentary young and middle aged women. Additionally short bouts of exercise may be more attractive than longer bouts of exercise for the beginning exerciser as they may more easily fit into the busy lifestyle encountered by many people in today's society. Sedentary young and middle-aged women should benefit from static flexibility exercises designed to improve and/or maintain functional flexibility and thus maintain mobility and reduce the incidence of muscular injury. Regular, brisk walking, incorporating some stair climbing, is likely to be beneficial in improving cardiovascular health and perhaps also in improving leg strength, thereby helping to improve and maintain functional physical fitness for both young and middle-aged sedentary women.

Familial and genomic analyses of postural changes in systolic and diastolic blood pressure

The physiological adaptation to the erect posture involves integrated neural and cardiovascular responses that might be determined by genetic factors. We examined the familial- and individual-specific components of variance for postural changes in systolic and diastolic blood pressure in 767 volunteer nuclear adult families from the Victorian Family Heart Study. In 274 adult sibling pairs, we made a genome-wide scan using 400 markers for quantitative trait loci linked with the postural changes in systolic and diastolic pressures. Overall, systolic pressure did not change on standing, but there was considerable variation in this phenotype (SD=8.1 mm Hg). Familial analyses revealed that 25% of the variance of change in systolic pressure was attributable to genetic factors. In contrast, diastolic pressure increased by 6.3 mm Hg (SD=7.0 mm Hg) on standing and there was no evidence of contributory genetic factors. Multipoint quantitative genome linkage mapping suggested evidence (Z=3.2) of linkage of the postural change in systolic pressure to chromosome 12 but found no genome-wide evidence of linkage for the change in diastolic pressure. These findings suggest that genetic factors determine whether systolic pressure decreases or increases when one stands, possibly as the result of unidentified alleles on chromosome 12. The genetics of postural changes in systolic blood pressure might reflect the general buffering function of the baroreflex; thereby, the predisposition to sudden decreases or increases in systolic pressure might cause postural hypotension or vessel wall disruption, respectively.

Effect of body tilt angle on fatigue and EMG activities in lower limbs during cycling

This study compared the rate of fatigue and lower limb EMG activities during high-intensity constantload cycling in upright and supine postures. Eleven active males performed seven cycling exercise tests: one upright graded test, four fatigue tests (two upright, two supine) and two EMG tests (one upright, one supine). During the fatigue tests participants initially performed a 10 s all-out effort followed by a constant-load test with 10 s all-out bouts interspersed every minute. The load for the initial two fatigue tests was 80% of the peak power (PP) achieved during the graded test and these continued until failure. The remaining two fatigue tests were performed at 20% PP and were limited to the times achieved during the 80% PP tests. During the EMG tests subjects performed a 10 s all-out effort followed by a constant-load test to failure at 80% PP. Normalised EMG activities (% maximum, NEMG) were assessed in five lower limb muscles. Maximum power and maximum EMG activity prior to each fatigue and EMG test were unaffected by posture. The rate of fatigue at 80% PP was significantly higher during supine compared with upright posture (-68 ± 14 vs. -26 ± 6 W min-1, respectively, P\0.05) and the divergence of the fatigue responses occurred by the second minute of exercise. NEMG responses were significantly higher in the supine posture by 1–4 min of exercise. Results show that fatigue is significantly greater during supine compared with upright high-intensity cycling and this effect is accompanied by a reduced activation of musculature that is active during cycling.

Exercise performance and V0₂ kinetics during upright and recumbent high-intensity cycling exercise

This study investigated cycling performance and oxygen uptake (VO₂) kinetics between upright and two commonly used recumbent (R) postures, 65ºR and 30ºR. On three occasions, ten young active males performed three bouts of high-intensity constant-load (85% peak workload achieved during a graded test) cycling in one of the three randomly assigned postures (upright, 65ºR or 30ºR). The first bout was performed to fatigue and second and third bouts were limited to 7 min. A subset of seven subjects performed a final constant-load test to failure in the supine posture. Exercise time to failure was not altered when the body inclination was lowered from the upright (13.1 ± 4.5 min) to 65ºR (10.5 ± 2.7 min) and 30ºR (11.5 ± 4.6 min) postures; but it was significantly shorter in the supine posture (5.8 ± 2.1 min) when compared with the three inclined postures. Resulting kinetic parameters from a tri-exponential analysis of breath-by-breath VO₂ data during the first 7 min of exercise were also not different between the three inclined postures. However, inert gas rebreathing analysis of cardiac output revealed a greater cardiac output and stroke volume in both recumbent postures compared with the upright posture at 30 s into the exercise. These data suggest that increased cardiac function may counteract the reduction of hydrostatic pressure from upright ~25 mmHg; to 65ºR ~22 mmHg; and 30ºR ~18 mmHg such that perfusion of active muscle presumably remains largely unchanged, and also therefore, VO₂ kinetics and performance during high-intensity cycling.

The imagined body – the cyborg

During a NASA conference in the 1960s, the term cyborg was created through an amalgamation of the terms ‘cybernetics’ and ‘organism’. Coined by concert pianist Manfred Clynes and research colleague Nathan Kline to describe the internal technological modification of the body. This new term resonated within popular culture and was quickly embraced by science fiction where the cyborg became a popular character. The image of the cyborg is often hyper-physical and hyper-sexual. The super sexualised woman who can shoot bullets from her breasts is a popular comic book cyborg representation. The Replicants from Riddley Scott’s Blade Runner and Arnold Schwaznegger’s role the Terminator are other examples where the technological and physical combination produces a terrifying hyper humans. Increasingly the future of our physicality is one that is intertwined with technology. Although the image of the cyborg is often an exaggerated character it holds within it real future possibilities. Consider the portable arm wrist communicator from the scifi classic Star Trek. The watch phone communication device was once an object of the imagination but now a reality in the personal mobile phone. This paper argues that through imagined imagery of the cyborg, future possibilities can be seen.

One example of the image of the cyborg representing possible human futures is the performance work Cyborpyg. Cyborpyg is a 40-minute contemporary dance work that integrates three dimensional (3D) animation and video media within the performance. Projected 3D animated prosthetic limbs appear to extend the dancers from within. These digital limbs integrate with dancer’s bodies transforming them into cyborgs. The animations are an extreme form of aesthetic modification reflecting the possible consequences of the integration of technology within the body. Cyborpyg also explores both utopic and dystipic themes within the cyborg paradigm. The dancing hybrid bodies perform magical feats not possible with an unmodified body. Feet twist into talons and flippers, eyes extend from the head, arms transform into robotic attachments. The dancer’s bodies also appear trapped in an unrelenting environment with prosthesis that appear to torture and inflict serious harm. This paper explores the idea that the imagined image of the cyborg reflects future possibilities for the human physicality.

Economic accountability in the context of local governance in the Philippines : a structural equation modelling approach

This study posits that by virtue of the enabling role of local governments, the economic development of their locality must be at the core of their public accountability, which is referred to here as “economic accountability”. Grounded on this idea of accountability, along with enabling theory and institutional theory, the study presents empirical evidence supportive of the argument that the enabling role of local governments, as manifested in a capacity to establish or adhere to formal institutional arrangements, has a direct impact on the entrepreneurial strategic posture and performance of local small and medium enterprises (SMEs) which are key players in local economic development.The results of the structural equation modelling support the view that institutional arrangements as manifestations of the enabling role of city governments are positively associated with an entrepreneurial strategic posture of local firms, which consequently improves the firms’ overall economic performance. Therefore, SME development in particular, and local economic development in general, should be part of the economic accountability of local governments in the Philippine context of local governance.

Seasonal periodicity of serum vitamin D and parathyroid hormone, bone resorption, and fractures : the Geelong Osteoporosis Study

In this population-based study, seasonal periodicity was seen with reduced serum vitamin D, increased serum PTH, and increased bone resorption in winter. This was associated with an increased proportion of falls resulting in fracture and an increased risk of wrist and hip fractures.

Introduction: In a population of women who reside in a temperate climate and do not generally receive dietary vitamin D supplementation, we investigated whether seasonal vitamin D insufficiency is associated with increased risk of fracture.

Materials and Methods: An observational, cross-sectional, population-based study set in southeastern Australia (latitude 38–39° S). Participants were drawn from a well-defined community of 27,203 women ≥55 years old: 287 randomly selected from electoral rolls, 1635 with incident fractures, and 1358 presenting to a university hospital with falls. The main outcome measures were annual periodicities of ultraviolet radiation, serum 25-hydroxyvitamin D [25(OH)D], serum parathyroid hormone (PTH), serum C-telopeptide (CTx), BMD, falls, and fractures.

Results: Cyclic variations in serum 25(OH)D lagged 1 month behind ultraviolet radiation, peaking in summer and dipping in winter (p < 0.001). Periodicity of serum PTH was the inverse of serum 25(OH)D, with a phase shift delay of 1 month (p = 0.004). Peak serum CTx lagged peak serum PTH by 1–2 months. In late winter, a greater proportion of falls resulted in fracture (p < 0.001). Seasonal periodicity in 439 hip and 307 wrist fractures also followed a simple harmonic model (p = 0.078 and 0.002, respectively), peaking 1.5–3 months after the trough in 25(OH)D.

Conclusions: A fall in 25(OH)D in winter is accompanied by increases in (1) PTH levels, (2) bone resorption, (3) the proportion of falls resulting in fracture, and (4) the frequency of hip and wrist fracture. Whether vitamin D supplementation in winter can reduce the population burden of fractures requires further investigation.

Segmentation of intentional human gestures for sports video annotation

We present results on the recognition of intentional human gestures for video annotation and retrieval. We define a gesture as a particular, repeatable, human movement having a predefined meaning. An obvious application of the work is in sports video annotation where umpire gestures indicate specific events. Our approach is to augment video with data obtained from accelerometers worn as wrist bands by one or more officials. We present the recognition performance using a Hidden Markov Model approach for gesture modeling with both isolated gestures and gestures segmented from a stream.

Hierarchical recognition of intentional human gestures for sports video annotation

We present a novel technique for the recognition of complex human gestures for video annotation using accelerometers and the hidden Markov model. Our extension to the standard hidden Markov model allows us to consider gestures at different levels of abstraction through a hierarchy of hidden states. Accelerometers in the form of wrist bands are attached to humans performing intentional gestures, such as umpires in sports. Video annotation is then performed by populating the video with time stamps indicating significant events, where a particular gesture occurs. The novelty of the technique lies in the development of a probabilistic hierarchical framework for complex gesture recognition and the use of accelerometers to extract gestures and significant events for video annotation.

Automatic labeling of sports video using umpire gesture recognition

We present results on an extension to our approach for automatic sports video annotation. Sports video is augmented with accelerometer data from wrist bands worn by umpires in the game. We solve the problem of automatic segmentation and robust gesture classification using a hierarchical hidden Markov model in conjunction with a filler model. The hierarchical model allows us to consider gestures at different levels of abstraction and the filler model allows us to handle extraneous umpire movements. Results are presented for labeling video for a game of Cricket.

The contributions of first nations ethnicity, income, and delays in surgery on mortality post-fracture : a population-based analysis

Summary We examined the independent contributions of First Nations ethnicity and lower income to post-fracture mortality. A similar relative increase in mortality associated with fracture appears to translate into a larger absolute increase in post-fracture mortality for First Nations compared to non-First Nations peoples. Lower income also predicted increased mortality post-fracture.

Introduction First Nations peoples have a greater risk of mortality than non-First Nations peoples. We examined the independent contributions of First Nations ethnicity and income to mortality post-fracture, and associations with time to surgery post-hip fracture.

Methods Non-traumatic fracture cases and fracture-free controls were identified from population-based administrative data repositories for Manitoba, Canada (aged ≥50 years). Populations were retrospectively matched for sex, age (within 5 years), First Nations ethnicity, and number of comorbidities. Differences in mortality post-fracture of hip, wrist, or spine, 1996–2004 (population 1, n = 63,081), and the hip, 1987–2002(Population 2, n = 41,211) were examined using Cox proportional hazards regression to model time to death. For hip fracture, logistic regression analyses were used to model the probability of death within 30 days and 1 year.

Results Population 1: First Nations ethnicity was associated with an increased mortality risk of 30–53 % for each fracture type. Lower income was associated with an increased mortality risk of 18–26 %. Population 2: lower income predicted mortality overall (odds ratio (OR) 1.15, 95 % confidence interval (CI) 1.07–1.23) and for hip fracture cases (OR 1.18, 95%CI 1.05–1.32), as did older age, male sex, diabetes, and >5 comorbidities (all p ≤ 0.01). Higher mortality was associated with pertrochanteric fracture (OR 1.14, 95 % CI 1.03–1.27), or surgery delay of 2–3 days (OR 1.34, 95 % CI 1.18–1.52) or ≥4 days (OR 2.35, 95 % CI 2.07–2.67).

Conclusion A larger absolute increase in mortality post-fracture was observed for First Nations compared to non-First Nations peoples. Lower income and surgery delay >2 days predicted mortality post-fracture. These data have implications regarding prioritization of healthcare to ensure targeted, timely care for First Nations peoples and/or individuals with lower income.

Design, development, and evaluation of a pinch-grasp haptic interface

Interaction with virtual or teleoperated environments requires contact with objects on a multipoint level. We describe the design of a pinch--grasp hand interface device for use as a grasping mechanism to complement haptic interfaces. To preserve a suitable level of transparency for human--computer interaction, this novel interface is designed for high-resolution contact forces, while centered around a lightweight structure. This functionality renders the device scalable and adaptable to a wide range of haptic interface structures and force level requirements. We present an optimal configuration for a pinch--grasp interface, which produces bidirectional forces to an operator's fingers and a rotational force to the wrist through a cable drive system. The device is characterized for use on a commercial haptic interface through demonstration of sustained peak performance and also workspace utilization. The dynamic performance of the pinch--grasp interface is experimentally determined, and the frequency response is identified to illustrate its contact force resolution.

Anodal tDCS applied during strength training enhances motor cortical plasticity

Purpose:
The objective of this study was to assess the effect of anodal transcranial direct current stimulation (a-tDCS) on voluntary dynamic strength and cortical plasticity when applied during a 3-wk strength training program for the wrist extensors.

Methods:
Thirty right-handed participants were randomly allocated to the tDCS, sham, or control group. The tDCS and sham group underwent 3 wk of heavy-load strength training of the right wrist extensors, with 20 min of a-tDCS (2 mA) or sham tDCS applied during training (double blinded). Outcome measures included voluntary dynamic wrist extension strength, muscle thickness, corticospinal excitability, short-interval intracortical inhibition (SICI), and silent period duration.

Results:
Maximal voluntary strength increased in both the tDCS and sham groups (14.89% and 11.17%, respectively, both P < 0.001). There was no difference in strength gain between the two groups (P = 0.229) and no change in muscle thickness (P = 0.15). The tDCS group demonstrated an increase in motor-evoked potential amplitude at 15%, 20%, and 25% above active motor threshold, which was accompanied by a decrease in SICI during 50% maximal voluntary isometric contraction and 20% maximal voluntary isometric contraction (all P < 0.05). Silent period decreased for both the tDCS and sham groups (P < 0.001).

Conclusion:
The application of a-tDCS in combination with strength training of the wrist extensors in a healthy population did not provide additional benefit for voluntary dynamic strength gains when compared with standard strength training. However, strength training with a-tDCS appears to differentially modulate cortical plasticity via increases in corticospinal excitability and decreases in SICI, which did not occur following strength training alone

Different current intensities of anodal transcranial direct current stimulation do not differentially modulate motor cortex plasticity

Transcranial direct current stimulation (tDCS) is a noninvasive technique that modulates the excitability of neurons within the motor cortex (M1). Although the aftereffects of anodal tDCS on modulating cortical excitability have been described, there is limited data describing the outcomes of different tDCS intensities on intracortical circuits. To further elucidate the mechanisms underlying the aftereffects of M1 excitability following anodal tDCS, we used transcranial magnetic stimulation (TMS) to examine the effect of different intensities on cortical excitability and short-interval intracortical inhibition (SICI). Using a randomized, counterbalanced, crossover design, with a one-week wash-out period, 14 participants (6 females and 8 males, 22–45 years) were exposed to 10 minutes of anodal tDCS at 0.8, 1.0, and 1.2 mA. TMS was used to measure M1 excitability and SICI of the contralateral wrist extensor muscle at baseline, immediately after and 15 and 30 minutes following cessation of anodal tDCS. Cortical excitability increased, whilst SICI was reduced at all time points following anodal tDCS. Interestingly, there were no differences between the three intensities of anodal tDCS on modulating cortical excitability or SICI. These results suggest that the aftereffect of anodal tDCS on facilitating cortical excitability is due to the modulation of synaptic mechanisms associated with long-term potentiation and is not influenced by different tDCS intensities.

That tender discipline: spacing, structured nothingness & kumbhaka

In the discussion that follows here, I will attempt what I have decided to call an onto-poetic reading of the yogic practice of kumbhaka. I choose the double-barrelled nomination 'onto-poetic' since I would like to use my experience of kumbhaka both to think of certain current ontological paradigms and implications, and also to allow myself the flexibility and discipline that I associate with the poetic register. I will draw on three particular thinkers, namely Alain Badiou, Jacques Derrida and Luce Irigaray. Badiou makes very explicit metaontological claims that, I believe, have something to contribute to a reading of kumbhaka. Derrida, for his part, has written extensively about phonologocentrism and its inherent links with speech and breath in the history of phallocentric metaphysics. Irigaray, finally, demonstrates a way to think unity, breath and praxis so as to bring these conceptual strands together in a kind of elegant, but urgent, agency.
What can the very practice of kumbhaka help me to think? And how can such thinking impact on what happens when I practice pranayama that involves kumbhaka? Kumbhaka can be situated as a practice within the broader discipline of Yogic pranayama. Yoga, as it often encountered in this historical moment in the so-called West, can appear to emphasize physical posture (which are certainly as aspect of its breadth). Yoga, however, as a technology of existential and ontological inquiry, has often, throughout its long and meandering history, made use of the manipulation of, and abstinence from, breath. I will begin by cursorily outlining the place of pranayama itself within the yogic canon of practice. Then, I will go on to explain specifically the technology of kumbhaka, before embarking on my onto-poetic discussion.