Effects of different step lengths at a preferred walking speed on forefoot, midfoot, and hindfoot motion in healthy young adults.

Hindfoot, midfoot, and forefoot motion during the stance phase of walking provide insights into the forward progression of the body over the feet via the rocker mechanisms. These segmental motions are affected by walking speed. Increases in walking speed are accomplished by increasing step length and cadence.

Walking in high-heel shoes induces redistribution of joint power and work.

Walking in high-heel shoes (HHS) decreases the push-off power and little research has examined the specific muscle groups that compensate for it. The purpose was to examine the effects of walking in HHS compared to barefoot on lower extremity net joint work and power. Fourteen young women walked in HHS and barefoot at a fixed speed of 1.

The effect of EMG biofeedback training on muscle activation in an impingement population.

Subacromial impingement syndrome (SAIS) is one of the most diagnosed causes of pain in the upper extremity. The purpose of this study was to investigate muscle activity between asymptomatic and SAIS shoulders on the same subject while understanding the effectiveness of EMG biofeedback training (EBFB) on bilateral overhead movements. Ten participants (7 male), that tested positive for 2/3 SAIS clinical tests, volunteered for the study.

The effects of hallux valgus and walking speed on dynamic balance in older adults.

Background: Hallux valgus (HV) contributes to deficits in static balance and increased fall risk in older adults. Very limited research has examined dynamic balance deficits in walking in this population. These individuals generally walk slowly, as balance challenge is lesser at slow speeds.

Effects of age, speed, and step length on lower extremity net joint moments and powers during walking.

During walking older adults' gait is slower, they take shorter steps, and rely less on ankle and more on knee and hip joint moments and powers compared to young adults. Previous studies have suggested that walking speed and step length are confounds that affect joint moments and powers. Our purpose was to examine the effects of walking speed and step length manipulation on net joint moments and powers in young and older adults.

Redistribution of joint moments and work in older women with and without hallux valgus at two walking speeds.

Background: Hallux valgus (HV) is a highly prevalent foot deformity in older women. Differences in lower extremity joint function of older women with and without HV during walking at slower and faster speeds are unknown.

Research Question: Does walking speed affect lower extremity joint range of motion (ROM) and net extensor joint moment and associated work in older women with and without HV?

Methods: Thirteen older women with HV and 13 controls completed five walking trials at 1.

Mechanical Demands at the Ankle Joint During Saut de Chat and Temps levé Jumps in Classically Trained Ballet Dancers.

Background: During ballet, injuries to the Achilles tendon are associated with the take-off phase of various jumps.

Research Question: The purpose of the study was to assess differences in mechanical demand on the body, specifically at the ankle, in two single-leg jumps commonly trained in ballet: a saut de chat (SDC) and a temps levé (TL).

Methods: Fifteen classically trained female dancers had 16 reflective markers placed on the lower body and each dancer performed each jump three times on a force plate.

Creatine electrolyte supplement improves anaerobic power and strength: a randomized double-blind control study.

Background: Creatine supplementation aids the Phosphagen system by increasing the amount of free creatine and phosphocreatine available to replenish adenosine triphosphate. The purpose of this study was to investigate the effects of a creatine and electrolyte formulated multi-ingredient performance supplement (MIPS) on strength and power performance compared to a placebo. Maximal strength along with total concentric work, mean rate of force development (mRFD), mean power, peak power, and peak force for both bench press and back squat were determined at pre-test and post-test separated by 6 weeks of supplementation.

ACUTE EFFECTS OF TWO HIP FLEXOR STRETCHING TECHNIQUES ON KNEE JOINT POSITION SENSE AND BALANCE.

Background: Tightness of hip flexor muscles has been recognized as a risk factor for various musculoskeletal injuries in the lower extremities.

Purpose: The purpose of this study was to examine the acute effects of two hip flexor stretching techniques (dynamic and hold-relax proprioceptive neuromuscular facilitation, HR-PNF) on hip extension (ROM), knee joint position sense (JPS) and balance in healthy college age students who exhibit tightness in hip flexor muscles.

Study Design: Pretest-posttest randomized experimental groups.

Effects of Age, Power Output, and Cadence on Energy Expenditure and Lower Limb Antagonist Muscle Coactivation During Cycling.

It is unknown if higher antagonist muscle coactivation is a factor contributing to greater energy expenditure of cycling in older adults. We determined how age, power output, and cadence affect energy expenditure and lower limb antagonist muscle coactivation during submaximal cycling. Thirteen younger and 12 older male participants completed 6-min trials at four power output-cadence conditions (75 W-60 rpm, 75 W-90 rpm, 125 W-60 rpm, and 125 W-90 rpm) while electromyographic and metabolic energy consumption data were collected.

Creatine-electrolyte supplementation improves repeated sprint cycling performance: A double blind randomized control study.

Background: Creatine supplementation is recommended as an ergogenic aid to improve repeated sprint cycling performance. Furthermore, creatine uptake is increased in the presence of electrolytes. Prior research examining the effect of a creatine-electrolyte (CE) supplement on repeated sprint cycling performance, however, did not show post-supplementation improvement.

Individuals With Knee Osteoarthritis Demonstrate Interlimb Asymmetry in Pedaling Power During Stationary Cycling.

Cycling is commonly prescribed for physical rehabilitation of individuals with knee osteoarthritis (OA). Despite the known therapeutic benefits, no research has examined interlimb symmetry of power output during cycling in these individuals. We investigated the effects of external workload and cadence on interlimb symmetry of crank power output in individuals with knee OA versus healthy controls.

Effects of age and physical activity status on redistribution of joint work during walking.

During walking older adults rely less on ankle and more on hip work than young adults. Disproportionate declines in plantarflexor strength may be a mechanism underlying this proximal work redistribution. We tested the hypothesis that proximal redistribution is more apparent in older compared to young adults and in sedentary compared to active individuals over multiple walking speeds.

Mechanisms underlying the reduced performance measures from using equipment with a counterbalance weight system.

Bench press throws are commonly used in the assessment of upper-body power and are often performed on a Smith machine that uses a counterbalance weight to reduce the net load on the barbell. The use of a counterbalanced Smith machine was recently shown to reduce performance measures, but the mechanisms for this reduction have not been established. The purpose of this study was to determine the underlying physiological and biomechanical causes of the reduced performance measures found when using a counterbalanced Smith machine.

Smith machine counterbalance system affects measures of maximal bench press throw performance.

Equipment with counterbalance weight systems is commonly used for the assessment of performance in explosive resistance exercise movements, but it is not known if such systems affect performance measures. The purpose of this study was to determine the effect of using a counterbalance weight system on measures of smith machine bench press throw performance. Ten men and 14 women (mean ± SD: age, 25 ± 4 years; height, 173 ± 10 cm; weight, 77.