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Bruno Marrier, Julien Robineau, Julien Piscione, Mathieu Lacome, Alexis Peeters, Christophe Hausswirth, Jean-Benoît Morin and Yann Le Meur

Peaking for major competition is considered critical for maximizing team-sport performance. However, there is little scientific information available to guide coaches in prescribing efficient tapering strategies for team-sport players.

Purpose:

To monitor the changes in physical performance in elite team-sport players during a 3-wk taper after a preseason training camp.

Methods:

Ten male international rugby sevens players were tested before (Pre) and after (Post) a 4-wk preseason training camp focusing on high-intensity training and strength training with moderate loads and once each week during a subsequent 3-wk taper. During each testing session, midthigh-pull maximal strength, sprint-acceleration mechanical outputs, and performance, as well as repeated-sprint ability (RSA), were assessed.

Results:

At Post, no single peak performance was observed for maximal lower-limb force output and sprint performance, while RSA peaked for only 1 athlete. During the taper, 30-m-sprint time decreased almost certainly (–3.1% ± 0.9%, large), while maximal lower-limb strength and RSA, respectively, improved very likely (+7.7% ± 5.3%, small) and almost certainly (+9.0% ± 2.6%, moderate). Of the peak performances, 70%, 80%, and 80% occurred within the first 2 wk of taper for RSA, maximal force output, and sprint performance, respectively.

Conclusions:

These results show the sensitivity of physical qualities to tapering in rugby sevens players and suggest that an ~1- to 2-wk tapering time frame appears optimal to maximize the overall physical-performance response.

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Juliana Limba da Fonseca, Marcio Magini and Thais Helena de Freitas

Objective:

To evaluate the influence of pain on vertical ground-reaction force (VGRF) in patients with low back problems and the effect of the Pilates method on the gait of these patients.

Design:

A single-blind randomized controlled trial.

Participants:

28 individuals assigned to a control group (n = 11) and a low-back group (n = 17), the latter of which was subdivided into a Pilates group (n = 8) and a no-Pilates group (n = 9).

Intervention:

The Pilates group undertook 15 sessions of Pilates.

Main Outcome Measures:

The VGRF parameters were recorded during preferred and faster walking speeds. The data were collected before and after the intervention.

Results:

The weight-acceptance rate and push-off rate were significantly less in the right lower limb of low-back group than of the control group at preferred speed. Improvements were seen in the Pilates group postintervention, with increased middle-support force for the left lower limb at faster walking speed and decreased pain; this did not occur in the no-Pilates group.

Conclusions:

These results suggest that patients with low back pain use strategies to attenuate the amount of force imposed on their body. The Pilates method can improve weight discharge in gait and reduce pain compared with no intervention.

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Jan M. Hondzinski, Li Li and Michael Welsch

We examined the effects of aging and lower limb sensory deficits (LLSD) on whole body control. Performances of a reaching task involving a step were measured in subjects with LLSD and young and older controls. Having LLSD was accompanied with greater reach errors and variability in lateral step deviations. Aging effects explained the smaller step deviations and longer movement times. These results suggest that older adults with LLSD have performance declines associated with deficits of the disease and aging that often differ, at least for this goal-directed discrete task. Furthermore, longer MT for older controls and shorter MT for LLSD subjects were associated with greater movement coupling. Longer movement periods likely offered older controls time to use sensory feedback to maintain good endpoint accuracy. Evidently, somatosensations from the limbs used during performance of whole body movements are required for the most accurate goal-directed control.

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Fátima Ramalho, Filomena Carnide, Rita Santos-Rocha, Helô-Isa André, Vera Moniz-Pereira, Maria L. Machado and António P. Veloso

Functional fitness (FF) and gait ability in older populations have been associated with increased survival rates, fall prevention, and quality of life. One possible intervention for the improvement of FF is well-structured exercise programs. However, there are inconsistent findings regarding the effects of exercise interventions in the maintenance of gait parameters. The aim of this protocol is to develop a community-based exercise intervention targeting an older population. The intervention aim is the improvement of gait parameters and FF. A control trial with follow-up will be performed. The primary outcome variables will be plantar pressure gait parameters. The secondary outcome variables will be aerobic endurance, lower limb strength, agility, and balance. These variables will be recorded at baseline and after 12, 24, and 36 weeks, in the intervention and control groups. If effective, this protocol can be used by exercise professionals in improving community exercise programs.

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Annabelle King, Mark Hancock and Joanne Munn

Context:

Functional strength measures correlate more closely with functional performance than non-functional strength measures.

Objectives:

To determine the reliability of the lateral step test as a measure of maximal strength.

Design:

Intertester repeated measures.

Setting:

Research laboratory.

Participants:

Twenty four healthy, pain free subjects.

Intervention:

Two protocols (A and B) were evaluated. The protocols were identical except protocol B involved a three second pause. Participants performed a one repetition maximum (1RM) for each protocol on two occasions separated by one week.

Main Outcome Measures:

Step height (nearest cm) representing

Results:

Both protocols demonstrated excellent reliability, protocol A: ICC = 0.94 (95% CI, 0.87 to 0.97), SEM = 1.47 cm. Protocol B: ICC= 0.94 (95%CI, 0.85 to 0.97).Percent close agreement within 2 cm was 83.3% for protocol A and 79.1% for protocol B.

Conclusion:

Both protocols demonstrated excellent inter-tester reliability as measures of functional lower limb strength.

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Dawne Larkin and Helen E. Parker

This study investigated landing patterns of children aged 7–9 years with either developmental coordination disorder (DCD) or without coordination problems (NC). Initially, 16 DCD and 15 NC children were videotaped performing two-foot landings from a height of 21.5 cm onto a force platform sampling at 500 Hz. Each landing was videotaped at 60 Hz. Regression modeling of the data identified that 72% of peak maximum loading force was explained by landing time, knee angle at touchdown, and hip joint range of motion. Dis-criminant function analysis using landing force, landing time and lower limb joint kinematic variables reliably separated the groups. In the second part, 12 DCD and 10 NC children participated in 6 weekly landing lessons. The only significant adjustment produced by the program was a decrease in the range of motion at the hip in response to instructions to look straight ahead and sit into the landing.

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Patricio A. Pincheira, Lauri Stenroth, Janne Avela and Neil J. Cronin

This study examined the contributions of individual muscles to changes in energetic cost of transport (COT) over seven walking speeds, and compared results between healthy young and elderly subjects. Twenty six participants (13 young aged 18–30; 13 old aged 70–80) were recruited. COT (O2/kg body mass/km) was calculated by standardizing the mean oxygen consumption recorded during steady state walking. Electromyography signals from 10 leg muscles were used to calculate the cumulative activity required to traverse a unit of distance (CMAPD) for each muscle at each speed. In the old group CMAPD was correlated with COT, presented higher and more variable values, and showed greater increases around optimal speed for all studied muscles. Soleus CMAPD was independent of speed in the young group, but this was not evident with aging. Greater energy cost of walking in older individuals seems to be attributable to increased energy cost of all lower limb muscles.

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Philippe C. Dixon and David J. Pearsall

The purpose of this study was to determine the effect of cross-slope on gait dynamics. Ten young adult males walked barefoot along an inclinable walkway. Ground reaction forces (GRFs), lower-limb joint kinematics, global pelvis orientation, functional leg-length, and joint reaction moments (JRMs) were measured. Statistical analyses revealed differences across limbs (up-slope [US] and down-slope [DS]) and inclinations (level; 0°; and cross-sloped, 6°). Adaptations included increases of nearly 300% in mediolateral GRFs (p < .001), functional shortening the US-limb and elongation of the DS-limb (p < .001), reduced step width (p = .024), asymmetrical changes in sagittal kinematics and JRM, and numerous pronounced coronal plane differences including increased US-hip adduction (and adductor moment) and decreased DS-hip adduction (and adductor moment). Data suggests that modest cross-slopes can induce substantial asymmetrical changes in gait dynamics and may represent a physical obstacle to populations with restricted mobility.

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Paulo Cesar Barauce Bento, Gleber Pereira, Carlos Ugrinowitsch and Andre L.F. Rodacki

Objective:

To analyze the effects of a water-based exercise program on peak torque (PT) and rate of torque development (RTD) during maximal voluntary ballistic isometric contractions of the lower limb muscles and the performance of a number of functional tests in the elderly.

Method:

Thirty-seven elderly were randomly assigned to water-based training (3 d/wk for 12 wk) or a control group. Extensor and flexor PT and RTD of the ankle, knee, and hip joints and functional tests were evaluated before and after training.

Results:

PT increased after training for the hip flexors (18%) and extensors (40%) and the plantar-flexor (42%) muscles in the water-based group. RTD increased after training for the hip-extensor (10%), knee-extensor (11%), and ankle plantar-flexor (27%) muscles in the water-based group. Functional tests also improved after training in the water-based group (p < .05).

Conclusion:

The water-based program improved PT and RTD and functional performance in the elderly.

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Ross H. Sanders

A boost is a skill used in water polo to raise the body for the purpose of shooting for goal or passing, or defending against these. The purpose of this study was to investigate kinematic variables contributing to height achieved in a boost. The kinematics of the vertex, shoulders, and lower limbs of 16 players ranging in ability from novice to elite were quantified using three-dimensional videographic techniques. Maximum height of the vertex with respect to water level ranged from 0.50 m to 0.90 m. A multiple regression model comprising the squared maximum resultant foot speed, range of knee joint extension, and initial trunk angle with respect to the horizontal accounted for 74% of the variance in height achieved. Anteroposterior and medio-lateral motions assisted in maintaining foot speed throughout the period of knee extension. The foot orientations and direction of foot motion of the elite players suggested that effective technique involves the use of both drag and lift forces.