Search Results

You are looking at 101 - 110 of 2,254 items for :

Clear All
Restricted access

Gongbing Shan, Dayna Daniels and Rongri Gu

Numerous methods for studying the prevention of falls and age-related sensorimotor degradation have been proposed and tested. Some approaches are too impractical to use with seniors or too expensive for practitioners. Practitioners desire a simple, reliable technique. The goals of this research were to develop such an approach and to apply it in exploring the effect of Tai Chi on age-related sensorimotor degradation. The method employed artificial-neural-network (ANN) models trained by using individuals’ center-of-pressure (COP) measurements and age. Ninety-six White and Chinese adults without Tai Chi training were tested. In contrast, a third group, Chinese seniors with Tai Chi training, was tested to ascertain any influence from Tai Chi on sensorimotor aging. This study supported ANN technology with COP data as a feasible tool in the exploration of sensorimotor degradation and demonstrated that Tai Chi slowed down the effects of sensorimotor aging.

Restricted access

Ted A Kaplan

A case is presented of an adolescent high school athlete found to have mildly elevated systolic blood pressure (BP) at the preseason group physical examination. As part of the evaluation to clear him for participation, a graded exercise stress test was performed. The test revealed a systolic BP at peak exercise of 260 mm Hg. The rationale for hygienic and pharmacologic management of this situation is discussed, and the results of this process are detailed. This patient was finally treated with nifedipine after unacceptable results with lisinopril, pindolol, and nonpharmacological approaches. The graded exercise test can be a valuable part of the evaluation of a hypertensive athlete. Besides revealing the occasional dangerous superelevation of BP, the test results can reveal the individual’s cardiovascular response to stress. This can provide insight into the etiology of and prognosis for the patient’s problem. Follow-up testing should be done after any treatment is provided.

Restricted access

Young-Shin Lee and Susan S. Levy

Objectives:

To examine physical activity (PA) in multiple contexts (household, walking, and leisure-time PA) and blood pressure (BP) across gender and income among older adults living independently.

Methods:

A convenience sample of 372 older adults completed 2 BP measurements and PA questionnaires.

Results:

Older adults with high incomes (≥$30,000) engaged in less household activity, more leisure time PA and better controlled their BP than those with low incomes (<$30,000). Men walked more than women. Older women in the low-income group had less controlled BP than those women in the high-income group. Participants with normal or controlled BP were engaged in more household and walking activities than those with uncontrolled BP.

Conclusion:

Findings suggest that older men and women at high or low-income levels have different mode of PA and BP management that should be considered for intervention strategies.

Restricted access

Denise M. Hill, Nic Matthews and Ruth Senior

This study used qualitative methods to explore the stressors, appraisal mechanism, emotional response, and effective/ineffective coping strategies experienced by elite rugby union referees during pressurized performances. Participants included seven male rugby union referees from the United Kingdom (Mage = 27.85, SD = 4.56) who had been officiating as full-time professionals for between 1 and 16 years (M = 4.85, SD = 5.42). Data revealed that the referees encountered a number of stressors, which were appraised initially as a ‘threat’, and elicited negatively-toned emotions. The referees were able to maintain performance standards under pressure by adopting proactive, problem- and emotion-focused coping strategies which managed effectively the stressors and their emotions. However, the use of avoidance-coping, reactive control, and informal impression management were perceived as ineffective coping strategies, and associated with poor performance and choking. Recommendations are offered to inform the psychological skills training of rugby union referees.

Restricted access

Johann Auer, Robert Berent, Markus Prenninger, Thomas Weber, Klaus Kritzinger, Martin Veits, Gudrun Lamm, Elisabeth Lassnig and Bernd Eber

Context:

Effects of a single bout of exercise at moderate altitude on blood pressure (BP) are largely unknown.

Objective:

To evaluate the effect of a single exercise bout at moderate altitude on BP.

Design:

Prospective, observational.

Setting:

Field study, Alpine mountains.

Participants:

127 men, 71 women (138 normotensive, 60 hypertensive).

Intervention:

Exercise duration: 2.5 ± 0.4 h; 650-m difference in altitude.

Main Outcome Measures:

BP and heart rate (HR).

Results:

Hypertensives had (1) higher systolic BP (SBP) and diastolic BP (DBP) before exercise (P < .01), whereas this difference was lost during exercise; (2) increased HR during the entire duration of exercise; and (3) significantly decreased SBP and DBP (P < .05) throughout the entire period of exercise.

Conclusions:

Exposure to a single exercise bout at moderate altitude is associated with a transient decrease in SBP and DBP, which is more pronounced in hypertensives.

Open access

Chad Seifried and Matthew Papatheodorou

The main purpose of this article is to provide suggestions to coaches on how they can assist young athletes in pressure packed situations to realize an ideal performance state. Suggestions provided address controlling emotions, adopting coping methods, practicing under game situations, embracing physical routines along with mental rehearsals, and engaging in self reflection/challenges. The strategies and discussions below should appear as vital for coaches attempting to help assist a young person’s future mental and emotional development. Furthermore, it should educate coaches and potentially others (e.g., spectators and media) on how to better handle these situations or instances so they can avoid the production of negative consequences on the lives of young people (e.g., choking label, social anxiety, poor self-esteem or image).

Restricted access

Rita Santos-Rocha and António Veloso

Mechanical load has been estimated during step exercise based on ground reaction force (GRF) obtained by force platforms. It is not yet accurately known whether these measures reflect foot contact forces once the latter depend on footwear and are potentially modified by the compliant properties of the step bench. The aim of the study was to compare maximal and mean plantar pressure (PP), and maximal GRF obtained by pressure insoles after performing seven movements both over two metal force platforms and over the step bench. Fifteen step-experienced females performed the movements at the cadences of 130 and 140 beats per minute. PP and GRF (estimated from PP) obtained for each floor condition were compared. Maximal PP ranged from 29.27 ± 9.94 to 47.07 ± 12.88 N/cm2 as for metal platforms, and from 28.20 ± 9.32 to 43.00 ± 13.80 N/cm2 as for the step bench. Mean PP ranged from 11.09 ± 1.62 to 14.32 ± 2.06 N/cm2 (platforms) and from 10.71 ± 1.54 to 14.22 ± 1.77 N/cm2 (step bench). GRF (normalized body weight) ranged from 1.43 ± 0.14 to 2.41 ± 0.24 BW (platforms) and from 1.38 ± 0.14 to 2.36 ± 0.19 BW (step bench). No significant statistical differences were obtained for most of the comparisons between the two conditions tested. The results suggest that metal force platform surfaces are suitable to assess mechanical load during this physical activity. The forces applied to the foot are similar to the softer step bench and the hard force platform surface. This may reflect the ability of the performers to adapt their movement patterns to normalize the impact forces in different floor conditions.

Restricted access

James L. Croft, Vinzenz von Tscharner and Ronald F. Zernicke

Compliant surfaces are used to challenge postural stability, but assessments are frequently limited to summary measures of center of pressure that do not provide insights into the temporal dynamics of motor coordination. Here, we measured center-of-pressure changes on three surfaces (solid, foam, and air-filled disc) and quantified the relative timing of changes in joint angles and muscle activity with respect to center-of-pressure changes. Nine active male subjects (20–30 years old) performed ten 30-s trials of unipedal stance on each of the three surfaces. Sway range, mean sway, mean sway velocity, path length, and fitted ellipse area increased, monotonically, from solid surface to foam to air-filled disc. The number of significant cross-correlations was greater for the compliant surfaces compared with the solid surface. Muscle activity preceded changes in center-of-pressure displacement, with the type of surface affecting the magnitude of the lead in the mediolateral direction. Center of pressure was more constrained on less stable surfaces and in the mediolateral direction.

Restricted access

Brad Hodgson, Laurie Tis, Steven Cobb, Shawn McCarthy and Elizabeth Higbie

Context:

Because of research variability and the increasing use of orthotics to manage lower extremity problems, further research is warranted.

Objective:

To investigate the effect of rear-foot- and forefoot-posted (PAL) and mediolongitu-dinal arch-supported (SOLE) orthotics on plantar pressure (PP) during walking.

Design:

Repeated measures.

Setting:

Laboratory.

Participants:

17 subjects with forefoot varus.

Intervention:

Data were collected at 0 and 6 weeks for no-orthotic and orthotic conditions.

Measurements:

PPs were collected with the EMED Pedar measurement system.

Results:

Zero weeks: PAL increased PP in lateral forefoot (LFF), middle toes (MT), and lateral toes (LT) and decreased PP in lateral heel (LH), medial forefoot (MFF), and central forefoot (CFF). SOLE increased PP for midfoot (MF) and LT and decreased PP in medial heel (MH), LH, and CFF. 6 weeks: PAL increased PP in LFF, MT, and LT and decreased PP in LH, MFF, and CFF. SOLE increased PP in MF and decreased PP in MH, LH, and LFF.

Conclusion:

The SOLE orthotic appeared to be more effective in attaining the goals of custom-molded-orthotic intervention.

Restricted access

Cyril Burdet and Patrice Rougier

To question the relation between uni- and bipedal postural skills, 21 subjects were required to stand on a force platform through uni- and bipedal conditions. These two protocols are commonly used paradigms to assess the balance capacities of healthy and disabled patients. The recorded displacements of the center of pressure (CP) were decomposed along mediolateral and anteroposterior axes and assessed through variance positions and parameters obtained from fractional Brownian motion (fBm) modeling to determine the nature and the spatiotemporal organization of the successive controlling mechanisms. The variances underline the relative independence of the two tasks. Nevertheless, as highlighted by the fBm framework, postural correction is initiated for the unipedal stance after shorter time delays and longer covered distances. When compared to bipedal standing, one of the main characteristics of unipedal standing is to induce better-controlled CP trajectories, as deduced from the scaling regimes computed from the fBm modeling. Lastly, the control of the CP trajectories during the shortest time intervals along the anteroposterior axis appears identical for both uni- and bipedal conditions. Unipedal and bipedal standing controls should thus be viewed as two complementary tasks, each providing specific and complementary insights into the postural control organization.