Loading range for the development of peak power in the close-grip bench press versus the traditional bench press

The close-grip bench press (CGBP) is a variation of the traditional bench press (TBP) that uses a narrower grip (~95% biacromial distance) and has application for athletes performing explosive arm actions where the hands are positioned close to the torso. Limited research has investigated CGBP peak power. Twenty-six strength-trained individuals completed a one-repetition maximum TBP and CGBP. During two other sessions, subjects completed two repetitions as explosively as possible with loads from 20% to 90% for each exercise, with peak power measured by a linear position transducer. A factorial ANOVA calculated between- and within-exercise differences in peak power. Partial correlations controlling for sex determined relationships between absolute and relative strength and peak power load. Peak power for the TBP occurred at 50% 1RM, and 30% 1RM for the CGBP. There were no significant (p = 0.680) differences between peak power at each load when comparing the TBP and CGBP. For the within-exercise analysis, there were generally no significant differences in TBP and CGBP peak power for the 20–50% 1RM loads. There were no significant relationships between strength and peak power load (p = 0.100–0.587). A peak power loading range of 20–50% 1RM for the TBP and CGBP is suggested for strength-trained individual

Trials and Tribulations: three key elements in running a successful mobile learning trial in a health care setting: Case Study

Case stud

Trials and Tribulations: three key elements in running a successful mobile learning trial in a health care setting: Case Study

Case stud

Effects of Preventative Ankle Taping on Planned Change-of-Direction and Reactive Agility Performance and Ankle Muscle Activity in Basketballers

This study investigated the effects of preventative ankle taping on planned change-of-direction and reactive agility performance and peak ankle muscle activity in basketballers. Twenty male basketballers (age = 22.30 ± 3.97 years; height = 1.84 ± 0.09 meters; body mass = 85.96 ± 11.88 kilograms) with no ankle pathologies attended two testing sessions. Within each session, subjects completed six planned and six reactive randomized trials (three to the left and three to the right for each condition) of the Y-shaped agility test, which was recorded by timing lights. In one session, subjects had both ankles un-taped. In the other, both ankles were taped using a modified subtalar sling. Peak tibialis anterior, peroneus longus (PL), peroneus brevis (PB), and soleus muscle activity was recorded for both the inside and outside legs across stance phase during the directional change, which was normalized against 10-meter sprint muscle activity (nEMG). Both the inside and outside cut legs during the change-of-direction step were investigated. Repeated measures ANOVA determined performance time and nEMG differences between un-taped and taped conditions. There were no differences in planned change-of-direction or reactive agility times between the conditions. Inside cut leg PL nEMG decreased when taped for the planned left, reactive left, and reactive right cuts (p = 0.01). Outside leg PB and soleus nEMG increased during the taped planned left cut (p = 0.02). There were no other nEMG changes during the cuts with taping. Taping did not affect change-of-direction or agility performance. Inside leg PL activity was decreased, possibly due to the tape following the line of muscle action. This may reduce the kinetic demand for the PL during cuts. In conclusion, ankle taping did not significantly affect planned change-of-direction or reactive agility performance, and did not demonstrate large changes in activity of the muscle complex in healthy basketballers

RELATIONSHIPS BETWEEN ARM SPAN AND THE MECHANICS OF THE ONE-REPETITION MAXIMUM TRADITIONAL AND CLOSE-GRIP BENCH PRESS

The traditional bench press (TBP), performed with a grip width that maximizes strength, is a popular exercise for developing the upper-body. The close-grip bench press (CGBP) is a variation of the TBP often used to emphasize the triceps brachii over prime movers such as the pectoralis major. An individual’s arm span (AS; distance between the middle fingers of each hand while the arms are outstretched) could affect the mechanics of each exercise, which may be exacerbated by the change in grip. This study investigated relationships between AS and TBP and CGBP mechanics in resistance-trained men. Twenty-one participants completed a one-repetition maximum (1RM) TBP and CGBP. The TBP was performed with the preferred grip (measured relative to biacromial distance [BAD]), and the CGBP with a grip width of 95% BAD. A linear position transducer measured: lift distance; peak and mean power, velocity, and force; the distance and time when peak power occurred; and work. Pearson’s correlations (r; p < 0.05) computed relationships between AS and TBP and CGBP mechanics. There were significant positive relationships between AS and TBP lift distance and work (r = 0.46 and 0.51, respectively). For the CGBP, there was a significant positive relationship between AS and work (r = 0.48). There were no other significant correlations between AS and lift mechanics. Resistance-trained men with a longer AS may move the bar further and perform more work in the 1RM TBP and CGBP. This could influence how coaches measure training volume, and intensity for individuals with different AS

A CASE STUDY OF A BEACH FLAGS START TECHNIQUE VARIATION IN ELITE SPRINTERS

Beach flags are a surf lifesaving event that involves a 20-meter sprint across sand. Sprinters begin in a prone position, facing the opposite direction to the intended sprint, before rising and turning to sprint and dive to capture a flag positioned in the sand. The typical start involves posterior movement away from the start line during the turn. Anecdotal evidence has suggested that beach flags sprinters can use variations to the start technique documented in the literature. Therefore, this research provided a case study of a start variation termed the pivot start. One male (age = 19 years; height = 1.74 m; mass = 66 kilograms), and one female (age = 23 years; height = 1.68 m; mass = 57 kilograms) elite sprinter were analyzed. A high-speed camera filmed the start. The analyzed data included: start time; hip and shoulder height during the turn; feet spacing; elbow, hip, knee, trunk lean, and trajectory angles at take-off, and descriptive statistics were derived. The analysis showed that the sprinters had no posterior movement behind the start line as they kept one leg on the start line, while the other leg was swung about the body so the sprinter rotated about the pivot leg. The rotatory start movements placed both sprinters into an effective, low body position for acceleration, indicated by trunk lean (~60°) and trajectory angle (~47°). These unique movement patterns should be trained accordingly for beach flags sprinters that use the pivot start

Do Clinical Correlates of Knee Osteoarthritis Predict Outcome to Intra-Articular Steroid Injections?

OBJECTIVE:To determine if clinical correlates of knee osteoarthritis(OA) affect likelihood of outcome to intra-articular steroid injections(IASI) in symptomatic knee OA. METHODS:Men and women aged≥40 years with painful knee OA who participated in an open label trial of IASI completed questionnaires and clinical examination. OMERACT-OARSI criteria were used to assess response to therapy in the short-term(within 2-weeks). Among those who initially responded, those whose pain had not returned to within 20% of the baseline KOOS-pain score at 6-months were characterised as longer-term responders. Log binomial regression was used to examine factors associated with outcome. RESULTS:199 participants were included, of whom 146(73.4%) were short-term and 40(20.1%) longer-term responders. Compared to short-term non-responders, participants with medial joint-line tenderness(RR=1.42;1.10-1.82), medial & lateral joint-line tenderness(RR=1.38;1.03-1.84), patellofemoral tenderness(RR=1.27;1.04-1.55), anserine tenderness(RR=1.27;1.06-1.52) and a belief that treatment would be effective(RR/unit increase, [range 0-10]=1.05;1.01-1.09), were more likely to be short-term responders. Aspiration of joint fluid(RR=0.79;0.66-0.95) and previous ligament/meniscus injury(RR=0.63;0.44-0.91) were associated with a reduced risk of being a short-term responder. Compared to initial non-responders and those whose pain recurred within 6-months, participants with higher number of pain sites(RR/unit increase, [range 0-10]=0.83;0.72-0.97), chronic widespread pain(RR=0.32;0.10-0.98), perceived chronicity of disease(RR/unit increase, [range 0-10]=0.86;0.78-0.94) and a higher depression score(RR/unit increase, [range 0-21]=0.89;0.81-0.99) were less likely to be longer-term responders. CONCLUSION:Among patients with symptomatic knee OA, tenderness around the knee was associated with better short-term outcome to IASI. However, clinical-related factors did not predict longer-term response while those with chronic widespread pain and depressive symptoms were less likely to obtain longer-term benefit

Solar-electric-propulsion cargo vehicles for split/sprint Mars mission

In support of the proposed exploration of Mars, an unmanned cargo ferry SEMM1 (Solar Electric Mars Mission) was designed. The vehicle is based on solar electric propulsion, and required to transport a cargo of 61,000 kg. The trajectory is a combination of spirals; first, out from LEO, then around the sun, then spiral down to low Mars orbit. The spacecraft produces 3.03 MWe power using photovoltaic flexible blanket arrays. Ion thrusters using argon as a propellant were selected to drive the ship, providing about 60 Newtons of thrust in low Earth orbit. The configuration is based on two long truss beams to which the 24 individual, self-deployable, solar arrays are attached. The main body module supports the two beams and houses the computers, electrical, and control equipment. The thruster module is attached to the rear of the main body, and the cargo to the front