A lower extremity strength-based profile of NCAA Division I women's basketball and gymnastics athletes: implications for knee joint injury risk assessment.

This study aimed to provide a comprehensive strength-based physiological profile of women's NCAA Division I basketball and gymnastic athletes; and to make sport-specific comparisons for various strength characteristics of the knee flexor and extensor muscles. A focus on antagonist muscle balance (hamstrings-to-quadriceps ratios, H:Q) was used to elucidate vulnerabilities in these at-risk female athletes. Fourteen NCAA Division I women's basketball and 13 gymnastics athletes performed strength testing of the knee extensors and flexors.

Biomechanical Comparison of Loaded Countermovement Jumps Performed on Land and in Water.

Louder, T, Bressel, E, Nardoni, C, and Dolny, D. Biomechanical comparison of loaded countermovement jumps performed on land and in water. J Strength Cond Res 33(1): 25-35, 2019-Researchers have observed physical improvements after the completion of aquatic-based jump training.

Biomechanical Comparison of Countermovement Jumps Performed on Land and in Water: Age Effects.

Context: The aquatic environment provides a low-impact alternative to land-based exercise and rehabilitation in older adults.

Objective: Evaluate the biomechanics of older adults and young adults performing jumping movements on land and in water.

Design And Setting: Cross-sectional, mixed-factorial experiment; adjustable-depth pool at sports medicine research facility.

Acute and chronic effects of aquatic treadmill training on land treadmill running kinematics: A cross-over and single-subject design approach.

The aim of this study was to determine if selected kinematic measures (foot strike index [SI], knee contact angle and overstride angle) were different between aquatic treadmill (ATM) and land treadmill (LTM) running, and to determine if these measures were altered during LTM running as a result of 6 weeks of ATM training. Acute effects were tested using 15 competitive distance runners who completed 1 session of running on each treadmill type at 5 different running speeds. Subsequently, three recreational runners completed 6 weeks of ATM training following a single-subject baseline, intervention and withdrawal experiment.

Age-Related Changes in Postural Sway Are Not Consistent Between Land and Aquatic Environments.

Background And Purpose: Quantifying how the environment (land vs water) influences age-related changes in postural sway is important for the development of new therapies that improve balance. The authors are not aware of any previous studies that have compared postural sway in an aquatic environment between age groups or when water depth and/or perturbations are incorporated into the comparison. The purpose of this study was to compare the effect of water depth and jet intensity on postural sway in older and younger adults.

High-intensity interval training on an aquatic treadmill in adults with osteoarthritis: effect on pain, balance, function, and mobility.

Although aquatic exercise is considered a potentially effective treatment intervention for people with osteoarthritis (OA), previous research has focused primarily on calisthenics in a shallow pool with the inherent limitations on regulating exercise intensity. The purpose of this study was to quantify the efficacy of a 6-week aquatic treadmill exercise program on measures of pain, balance, function, and mobility. Eighteen participants (age = 64.

Lower-extremity muscle activity during aquatic and land treadmill running at the same speeds.

Context: Muscle activation during aquatic treadmill (ATM) running has not been examined, despite similar investigations for other modes of aquatic locomotion and increased interest in ATM running.

Objectives: The objectives of this study were to compare normalized (percentage of maximal voluntary contraction; %MVC), absolute duration (aDUR), and total (tACT) lower-extremity muscle activity during land treadmill (TM) and ATM running at the same speeds.

Design: Exploratory, quasi-experimental, crossover design.

Aquatic-treadmill walking: quantifying drag force and energy expenditure.

Context: Quantification of the magnitudes of fluid resistance provided by water jets (currents) and their effect on energy expenditure during aquatic-treadmill walking is lacking in the scientific literature.

Objective: To quantify the effect of water-jet intensity on jet velocity, drag force, and oxygen uptake (VO2) during aquatic-treadmill walking.

Design: Descriptive and repeated measures.

Trunk muscle activity during spine stabilization exercises performed in a pool.

Objectives: To compare trunk muscle activity levels among a variety of therapeutic aquatic exercises designed for patients with low back pain.

Study Design: Quantitative observational laboratory study.

Setting: Sports medicine clinic housed in a University.

Whole-body vibration effects on the muscle activity of upper and lower body muscles during the baseball swing in recreational baseball hitters.

The purpose of this study was to evaluate the effects of whole-body vibration (WBV) on the muscle recruitment of selected upper and lower body muscles during the baseball swing. Participants were recreationally trained males (n = 16, 22 +/- 2 years, 181.4 +/- 7.

Trunk muscle activity during exercises performed on land and in water.

Purpose: The study's purpose was to determine whether trunk muscle activity levels are different during spine stability exercises performed in water compared with on land.

Methods: Eleven male participants performed four abdominal trunk exercises on land and in water at the depth of the xiphoid. The exercises were abdominal hollowing, abdominal bracing, and anteroposterior and mediolateral pelvic tilts.

Effects of muscular strength, exercise order, and acute whole-body vibration exposure on bat swing speed.

The purposes for this study were to investigate effects of acute whole-body vibration (WBV) exposure and exercise order on bat speed and to examine relationship between muscular strength and bat speed. All participants were recreationally trained men (n = 16; 22 ± 2 years; 181.4 ± 7.

Comparison and reproducibility of sEMG during manual muscle testing on land and in water.

The objectives of this study were to: (1) compare the sEMG recordings from maximal voluntary contractions (MVC), and (2) examine the reproducibility of sEMG recordings from MVCs for selected lower extremity muscles derived from manual muscle testing (MMT) on dry land, and in water prior to and following aquatic treadmill running. Twelve healthy recreational male runners participated. The selected muscles were: M.

Association between attributes of a cyclist and bicycle seat pressure.

Introduction: Bicycle seat pressure is thought to be the principal risk factor for bicycle seat injuries such as erectile dysfunction; however there is a lack of understanding regarding the characteristics of a cyclist that predict bicycle seat pressure.

Aim: The purpose of this study was to determine if select attributes of a cyclist are associated with seat pressure during stationary bicycling. A secondary purpose was to determine which of the associated attributes were the best predictors of seat pressure and if they were consistent between two different seats.

Acute effects of various weighted bat warm-up protocols on bat velocity.

Although research has provided evidence of increased muscular performance following a facilitation set of resistance exercise, this has not been established for use prior to measuring baseball bat velocity. The purpose of this study was to determine the effectiveness of selected weighted bat warm-up protocols to enhance bat velocity in collegiate baseball players. Nineteen collegiate baseball players (age = 20.

The effects of specific preconditioning activities on acute sprint performance.

Previous research suggests that specific preconditioning activities such as whole-body vibration (WBV) and resistance training may play an important role in ensuing dynamic activities. The purpose of this study was to examine the effects of 2 preconditioning activities, WBV and power cleans (PC), on acute sprint performance. Two studies were conducted in which 14 (WBV) and 9 (PC) male track and field athletes were subjects.

Whole body vibration exercise: training and benefits.

In recent years, it has been suggested that exercise using whole body vibration (WBV) platforms may increase muscle activity and subsequently enhance muscle performance in both acute and chronic conditions. WBV platforms produce frequencies ranging from 15-60 Hz and vertical displacements from ~1-11 mm, resulting in accelerations of ~2.2-5.

Peak cardiorespiratory responses during aquatic and land treadmill exercise.

Purpose: Aquatic treadmill exercise has traditionally been used for aerobic training during rehabilitation; however, its ability to elicit comparable cardiorespiratory stress compared with land exercise is unclear. The purpose of this study was to investigate the cardiorespiratory (CR) responses elicited during maximal-effort protocols using an aquatic treadmill (ATM) and a land treadmill (TM).

Methods: Twenty-three college runners participated in two continuous, incremental peak oxygen consumption protocols (ATM and TM) until volitional exhaustion.

Modifiable lifestyle factors affecting bone health using calcaneus quantitative ultrasound in adolescent girls.

Unlabelled: One hundred and fourteen girls were measured for calcaneus QUS (stiffness index score), calcium intake, weight, and total hours spent in physical activity (moderate to high-impact activities and low to no-impact activities). Multiple regression analysis indicated that hours spent in moderate to high-impact activities, current calcium intake, and weight significantly predicted SI.

Introduction: To determine the influence of modifiable lifestyle factors on adolescent girls' bone health measured by calcaneus quantitative ultrasound (QUS).

Optimal loading during two different leg-press movements in female rowers.

Purpose: The purpose of this study was to determine the optimal load for power during concentric only (CO) and stretch-shortening cycle (SSC) leg-press movements during the initial portion of the concentric phase as well as throughout the entire concentric phase in trained female rowers.

Methods: Thirty female rowers (age = 19.6 +/- 1.

Occupational physical activity as an indicator of health and fitness.

Recent government guidelines suggest that simply increasing physical activity, regardless of mode, leads to improved health profiles. This study examined the relationship between amount of work-related physical activity of United States Forest Service (USFS) workers and 12 indicators of health and fitness. Subjects were 110 USFS workers recruited from 8 separate USFS ranger stations in the Pacific Northwest.

Validity of lower extremity strength and power utilizing a new closed chain dynamometer.

Purpose: The purpose of this study was to compare selected variables measured on a traditional isokinetic dynamometer (Cybex II) with a new lower extremity, closed chain dynamometer (Omnikinetic, OmK).

Methods: Twelve subjects (6 male, 6 female, age = 28+/-5 yr, mean +/- SD) performed Cybex II knee flexion and extension at 1.05, 3.

Psychosocial, behavioral, and biometric characteristics of stages of exercise adoption.

This study incorporates the Stages of Change model to examine the relationship between the stages of exercise adoption and indicators of health and fitness. Subjects were 198 United States Forest Service (USFS) workers recruited from 8 USFS ranger stations in the Pacific Northwest. Analysis indicated that those subjects in Action and Maintenance stages of exercise adoption differed significantly from those in Preparation and Precontemplation/Contemplation stages on a variety of indicators of both health and fitness.

A new bilateral closed chain assessment technique: methods and error analysis.

Purpose: The purpose of this paper is to present the Omnikinetic methodology for clinical evaluation of lower extremity function, to characterize its sensitivity to errors, and to present typical data for an assessment protocol.

Methods: A 5-bar, 2-degree of freedom linkage was used to model the geometry of the crank, pedal, and lower extremity. Two-degree force transducers at the pedal were used to calculate center of pressure and force applied at the foot.

Moderate physical activity can increase dietary protein needs.

Six healthy men completed three 1-hr bouts of treadmill walk-jogging at low (L; 42 +/- 3.9% VO2max), moderate (M; 55 +/- 5.6%), and high (H; 67 +/- 4.