Sports Sciences Commons^™

Energy Flow Differences In Throwing Arm Joints Between Javelin And Weighted Balls In Male Javelin Throwers, Hans-Peter Köhler, Kristof Kipp, Nikola Prvulović, Maren Witt

Exercise Science Faculty Research and Publications

Introduction: To enhance release velocity during competition, javelin throwers incorporate implements of varying mass into their training regimens. Previous research has demonstrated that, although velocity contributes quadratically to the computation of kinetic energy, heavier implements generate substantially greater kinetic energy at the moment of release, despite markedly lower release velocities. The primary objective of the present investigation was to analyze energy transfer within the throwing arm to gain deeper insight into the biomechanical mechanisms underlying the use of implements with different masses.

Methods: The three-dimensional coordinates of 16 reflective markers were recorded for 6 athletes during throws using 6 different …

Mechanisms For The Age-Related Increase In Fatigability Of The Elbow Flexor Muscles In Healthy Adults, Blaine E. Arney, Andrew Kuplic, Mitchell D. Adam, Christopher W. Sundberg, Sandra Hunter

Exercise Science Faculty Research and Publications

The mechanisms for the age-related increase in fatigability of the elbow flexor muscles during dynamic contractions are unknown. The purpose of this study was to determine the contribution of supraspinal and contractile mechanisms for the age-related increase in fatigability of the elbow flexor muscles. Twenty-eight young (23.2 ± 2.6 years; 14 females) and 32 older adults (72.6 ± 5.6 years; 15 females) performed 80 maximal velocity contractions at 20% of maximal isometric strength. Voluntary activation and muscle contractile properties were assessed before and immediately following the fatiguing exercise using transcranial magnetic stimulation (TMS) and electrical stimulation. Fatigability (% reduction in …

Sex-Based Differences In The Representation Of Top Youth Athletes, Jessica J. James, Sandra K. Hunter, Elizabeth P. Bueckers, Michael J. Joyner, Jonathon W. Senefeld

Exercise Science Faculty Research and Publications

Although emerging research demonstrates that male athletes outperform female athletes before puberty, the effect of these sex-related advantages on ordinal ranking of top performances remains unclear.

Objectives

Among overall top performances of youth track and swimming athletes, we aimed to determine 1) the proportional number of male compared with female athletes represented and 2) at what age females are no longer represented.

Methods

Finishing times and sex of the top 10 and top 100 performances of youth runners and swimmers between 5 and 18 yr were abstracted from online U.S.-based databases for four running (100 m–800 m) and six freestyle …

Walking Performance Is Worse In Black Than White People With Multiple Sclerosis, Robert W. Motl, Deborah Backus, Jeffrey R. Hebert, Alexander V. Ng, Kevin K. Mccully, Whitney N. Neal, Hollie Schmidt, Robert Mcburney, Prudence Plummer, Francois Bethoux, John Lowman, Gary R. Cutter

Exercise Science Faculty Research and Publications

Background

There is emerging evidence for poor health outcomes among Black people with MS, and Black people with MS may have worse walking performance than White counterparts.

Purpose

The current study examined if Black participants with MS had slower walking speed (timed 25-foot walk, T25FW) and shorter walking distance (six-minute walk, 6MW) than White participants, and if these differences were accounted for by demographic variables, physical activity, disease/clinical characteristics, and Social Determinants of Health (SDOH).

Method

The analysis included samples of Black (N = 105) and White (N = 246) participants with MS who completed the T25FW and 6MW, underwent …

Prediction Of Snatch And Clean And Jerk Performance From Physical Performance Measures In Elite Male Weightlifters, Ingo Sandau, Kristof Kipp

Exercise Science Faculty Research and Publications

This study aimed to build a valid model to predict maximal weightlifting competition performance using ordinary least squares linear regression (OLR) and penalized (Ridge) linear regression (penLR) in 29 elite male weightlifters. One repetition maximum (1RM) or 3RM test results of assistant exercises were used as predictors. Maximal performance data of competition and assistant exercises were collected during a macrocycle in preparation for a competition. One repetition maximum snatch pull, 3RM back squat, 1RM overhead press, and body mass were used to predict the 1RM snatch; and 1RM clean pull, 3RM front squat, 1RM overhead press, and body mass were …

Effect Of Trauma Type And Trauma Burden On Self-Efficacy For Physical Exercise In Military Veterans, Kaley E. Davis, Meghan M. Bennett, Cecilia J. Hillard, Jeffrey Whittle, Zeno Franco, Rachel E. Bollaert, Jacklynn M. Fitzgerald

Exercise Science Faculty Research and Publications

Introduction

United States (U.S.) military veterans experience significant physical health problems. Lifestyle modifications, such as increasing daily physical activity, are often considered the first course of action in treatment for the general public. However, veterans report low levels of physical activity, often due to perceived barriers to engaging in exercise. Trauma exposure type and cumulative trauma burden may be differentially associated with exercise attitudes and behaviors.

Methods

We surveyed U.S. military veterans on perceived self-efficacy to overcome barriers to engaging in exercise and physical activity levels. Additionally, we explored the relationship between the type of traumatic event exposure and cumulative …

Relative Muscular Effort In The Older Adults During The Sit-To-Stand Task: Monitoring Neuromuscular Reserve And Movement Limitations, Nayun Ahn, Michael H. Haischer, Cara L. Lewis, Kristof Kipp

Exercise Science Faculty Research and Publications

Background

Due to lower maximum strength, older adults purportedly need to exert greater muscular effort to stand up from a chair. This study investigated joint-specific muscular effort during a sit-to-stand by calculating relative-muscular-effort and investigating differences between healthy older and young adults.

Methods

Fifteen older (age: 69.9 ± 3.5 years) and 15 young (age: 22.2 ± 2.6 years) adults performed five self-paced sit-to-stand trials. Kinematic and kinetic data were collected and used to calculate inverse dynamics net joint moment. Peak isometric knee and hip extensor torques were measured and used as inputs to regression models that predicted angle- and velocity-dependent …

Performance Of Artificial Neural Network Compared To Multi-Linear Regression In Prediction Of Countermovement Jump Height, Amirhossein Emamian, Alireza Hashemi Oskouei, Kristof Kipp, Rasoul Azreh

Exercise Science Faculty Research and Publications

Previous research has used primarily linear regression models to predict jump height and establish contributors of performance. The purpose of this study was to compare the performance of artificial neural network (ANN) and multi-linear regression (MLR) in prediction of countermovement jump (CMJ) height and investigating the contribution of kinematic variables to CMJ performance. Thirty-four healthy young male athletes performed a total of 204 CMJ while eight kinematic variables (the hip, knee, and ankle angles at the begging of the concentric phase of CMJ, the hip and knee take-off angles, and the shoulder, hip, and knee maximum angular velocities) were used …

Validation Of Scores From A Telephone Administered Multiple Sclerosis Walking Scale-12 In Persons With Multiple Sclerosis, Robert W. Motl, Prudence Plummer, Deborah Backus, Jeffrey R. Hebert, Whitney N. Neal, Alexander V. Ng, John Lowman, Francois Bethoux, Hollie Schmidt, Robert Mcburney, Kevin K. Mccully, Gary R. Cutter

Exercise Science Faculty Research and Publications

Background

The Multiple Sclerosis Walking Scale-12 (MSWS-12) has typically been delivered through paper-and-pencil or computer-based administration.

Purpose

This study examined the validity of inferences from scores derived via a telephone administration of the MSWS-12 applied as part of screening of participants with walking dysfunction into a clinical trial of exercise training in MS.

Method

The MSWS-12 was administered on two occasions separated by approximately 2 weeks through the telephone and then in-person (i.e., computer-based administration). Participants further completed the Patient Determined Disease Steps (PDDS) scale, timed 25-foot walk (T25FW), six-minute walk (6MW), Modified Fatigue Impact Scale (MFIS), and Multiple Sclerosis …

Effects Of Photobiomodulation Therapy On Muscle Function In Individuals With Multiple Sclerosis, Mitra Rouhani, Miguel Tolentino, Jeri-Anne Lyons, Alexander V. Ng

Exercise Science Faculty Research and Publications

Background

In people with multiple sclerosis (pwMS), muscle fatigue and weakness are common issues that can interfere with daily activities. Photobiomodulation therapy (PBMT), comprising light in a 600–1100 nm bandwidth, is a low-level laser therapy thought to improve muscle performance in non-disease populations, in part, by improving mitochondrial function and thus, might be beneficial in pwMS. Given this potential, we aimed to investigate the effects of PBMT on muscle performance in pwMS, both in the short-term and over an extended period.

Methods

This study consisted of two parts with a randomized double-blind crossover design. In study I, muscle function was …

Middle-Range Scores From The Patient Determined Disease Steps Scale Reflect Varying Levels Of Walking Dysfunction In Multiple Sclerosis, Robert W. Motl, Whitney Neal, Deborah Backus, Jeffrey Hebert, Kevin K. Mccully, Francois Bethoux, Prudence Plummer, Alexander V. Ng, John Lowman, Hollie Schmidt, Robert Mcburney, Gary R. Cutter

Exercise Science Faculty Research and Publications

Background

Multiple sclerosis (MS) is a leading cause of neurological disability among young and middle-aged adults worldwide, and disability is measured using a variety of approaches, including patient reported outcome measures (PROMs) such as the Patient Determined Disease Steps (PDDS) scale. There is limited evidence for the validity of inferences from the middle-range of scores on the PDDS (i.e., 3 “gait disability” – 6 “bilateral support”), but that range of scores seemingly represents moderate disability characterized by varying levels of walking dysfunction.

Purpose

The current study examined whether the middle-range of scores from the PDDS reflect varying levels of walking …

Midlife Health Crisis Of Former Competitive Athletes: Dissecting Their Experiences Via Qualitative Study, Jacob J. Capin, Taylor Wolf, Jena Heck Street, Carolyn S. Smith, Shannon L. Lennon, William B. Farquhar, Sandra K. Hunter, Linda B. Piacentine

Physical Therapy Faculty Research and Publications

Sports participation confers many health benefits yet greatly increases injury risk. Long-term health outcomes in former athletes and transition to life after competitive sports are understudied. Ending a sport may pose physical and psychosocial challenges. The purpose was to determine the lived experiences of former competitive athletes and how their sports participation impacted their long-term health and well-being. Former college varsity athletes participated in semistructured interviews focusing on their experiences, including past and current health, the impact of injuries, activity, exercise, diet and transition to life after competitive sport. Thematic analysis was completed using a collaborative, iterative process. Thirty-one (16 …

Sex Differences In Fatigability And Recovery Following A 5 Km Running Time Trial In Recreationally Active Adults, Maria Solleiro Pons, Sandra K. Hunter, Paul Ansdell

Exercise Science Faculty Research and Publications

Females demonstrate greater fatigue resistance compared to males in tasks ranging from single-limb contractions to whole-body exercise, including running. Many of the studies investigating sex differences in fatigability following running, however, occur after long duration, low-intensity tasks and it is unknown whether there is a sex difference in fatigability following high-intensity running. This study compared fatigability and recovery following a 5 km running time trial in young males and females. Sixteen recreationally active participants (8 males, 8 females, age: 23 ± 4 years) completed a familiarisation and experimental trial. Knee-extensor maximal voluntary contractions (MVCs) were performed before and up to …

The Biological Basis Of Sex Differences In Athletic Performance: Consensus Statement For The American College Of Sports Medicine, Sandra K. Hunter, Siddhartha S. Angadi, Aditi Bhargava, Joanna Harper, Angelica Lindén Hirschberg, Benjamin D. Levine, Kerrie L. Moreau, Natalie J. Nokoff, Nina S. Stachenfeld, Stéphane Bermon

Exercise Science Faculty Research and Publications

Biological sex is a primary determinant of athletic performance because of fundamental sex differences in anatomy and physiology dictated by sex chromosomes and sex hormones. Adult men are typically stronger, more powerful, and faster than women of similar age and training status. Thus, for athletic events and sports relying on endurance, muscle strength, speed, and power, males typically outperform females by 10%–30% depending on the requirements of the event. These sex differences in performance emerge with the onset of puberty and coincide with the increase in endogenous sex steroid hormones, in particular testosterone in males, which increases 30-fold by adulthood, …

Muscle-Specific Contributions To Vertical Ground Reaction Force Profiles During Countermovement Jumps: Case Studies In College Basketball Players, Kristof Kipp, Hoon Kim

Exercise Science Faculty Research and Publications

The purpose of this study was to determine muscle-specific contributions to various types of vertical ground reaction force (vGRF) profiles in collegiate basketball players. Players from a men's (n = 5; height: 1.84 ± 0.14 m; mass: 92.8 ± 11.4 kg) and a women's (n = 5; 1.71 ± 0.09 m; mass: 80.1 ± 17.6 kg) basketball team completed 3–5 countermovement jumps (CMJ) while motion capture and force plate data were recorded. Muscle-specific contributions to vGRF were calculated through vGRF decomposition analysis. Profiles of vGRF were analyzed based on the presence of unimodal or bimodal peaks during the …

Running To The Beat: Does Listening To Music Affect Running Cadence And Lower Extremity Biomechanics?, Carolyn Meinerz, Jessica M. Fritz, Janelle A. Cross, Cody C. Dziuk, Kristof Kipp, Carole Vetter

Exercise Science Faculty Research and Publications

Background

Gait retraining can be effective in altering lower extremity biomechanics and reducing risk of injury. In attempts to alter running gait, previous studies used metronomes to manipulate cadence.

Research question

The aim of this study was to determine if manipulating running cadence via music could alter lower extremity biomechanics.

Methods

Eighteen runners ran at a self-selected speed (SS) and ran to music where the beats per minute (bpm) of the songs was increased by 5% (+5%) and 10% (+10%). Kinematic and kinetic data were collected with a motion capture system and a triaxial accelerometer. A one-way repeated measures analysis …

Localized Pain And Fatigue During Recovery From Submaximal Resistance Exercise In People With Fibromyalgia, Giovanni Berardi, Christine Eble, Sandra K. Hunter, Marie K. Hoeger Bement

Exercise Science Faculty Research and Publications

Objective

Exercise is recommended as a main treatment in fibromyalgia. However, many people have limited exercise tolerance and report exacerbated pain and fatigue during and following a bout of exercise. This study examined the local and systemic changes in perceived pain and fatigue during exercise and through the 3-day recovery following isometric and concentric exercises in people with and without fibromyalgia.

Methods

Forty-seven participants with a physician diagnosis of fibromyalgia (44 women; mean age [SD] = 51.3 [12.3] years; mean body mass index [SD] = 30.2 [6.9]) and 47 controls (44 women; mean age [SD] = 52.5 [14.7] years; mean …

Physical Function Across The Lifespan In Adults With Multiple Sclerosis: An Application Of The Short Physical Performance Battery, Brenda Jeng, Petra Šilić, Rachel E. Bollaert, Brian M. Sandroff, Robert W. Motl

Exercise Science Faculty Research and Publications

Background

Multiple sclerosis (MS) typically has its onset in early and middle adulthood, but the population is steadily becoming more dominated by older adults. One of the primary consequences of both MS and aging involves declines of lower extremity physical function and mobility. This cross-sectional study compared physical function status based on Short Physical Performance Battery (SPPB) summary and component scores between persons with MS and healthy controls across 6 age groups. We further examined associations between SPPB summary scores and component scores as well as associations between summary scores and measures of physical and cognitive function for identifying the …

“It’S About Being Healthy”; A Novel Approach To The Socio-Ecological Model Using Family Perspectives Within The Latinx Community, Bethany Korom, Meghan Malloy, Caroline Remmers, Mari Cevilla, Kelly Dione, Paula E. Papanek, Jeffrey Condit, David Nelson

Exercise Science Faculty Research and Publications

Background

The Latinx community is at risk for obesity, type 2 diabetes, and other chronic illnesses. Culturally appropriate, community facing physical activity (P.A.) and nutrition programs may provide the basis for families to improve their health status. Our objectives are as follows: 1. To investigate synergistic factors within this type of program that play a role in creating an environment for participants to learn and practice healthy behaviors. 2. To apply factors into a novel model of components that support health and wellness. 3. To design an intervention for future implementation and evaluation.

Methods

A two-year P.A. and nutrition program, …

Muscle-Specific Contributions To Lower Extremity Net Joint Moments While Squatting With Different External Loads, Kristof Kipp, Hoon Kim, William I. Wolf

Exercise Science Faculty Research and Publications

The purpose of this study was to determine muscle-specific contributions to lower extremity net joint moments (NJMs) during squats with different external loads. Nine healthy subjects performed sets of the back squat exercise with 0, 25, 50, and 75% of body mass as an added external load. Motion capture and force plate data were used to calculate NJMs and to estimate individual muscle forces via static optimization. Individual muscle forces were multiplied by their respective moment arms to calculate the resulting muscle-specific joint moment. Statistical parametric mapping (α = 0.05) was used to determine load-dependent changes in the time series …

Maximal Strength In Relation To Force And Velocity Patterns During Countermovement Jumps, Michael H. Haischer, John Krzyszkowski, Stuart Roche, Kristof Kipp

Exercise Science Faculty Research and Publications

Maximal strength is important for the performance of dynamic athletic activities, such as countermovement jumps (CMJ). Although measures of maximal strength appear related to discrete CMJ variables, such as peak ground reaction forces (GRF) and center-of-mass (COM) velocity, knowledge about the association between strength and the time series patterns during CMJ will help characterize changes that can be expected in dynamic movement with changes in maximal strength. Purpose: To investigate the associations between maximal strength and GRF and COM velocity patterns during CMJ. Methods: Nineteen female college lacrosse players performed 3 maximal-effort CMJs and isometric midthigh pull. GRF …

Resilience Among Older Adults With Multiple Sclerosis: Pattern And Correlates, Dena Sadeghi-Bahmani, Ariel Kidwell, Rachel E. Bollaert, Robert W. Motl

Exercise Science Faculty Research and Publications

Background

There is an increasing number of older adults with multiple sclerosis (MS) who present with significant challenges associated with aging in conjunction with a chronic, disabling disease. Resilience has been associated with healthy aging in the general population, yet there is limited research on resilience and its correlates among older adults with MS. The current study investigated the difference in resilience between older adults with MS and demographically matched healthy controls. We then examined the associations between resilience and functional, symptomatic, socio-behavioral, and QOL outcomes, along with demographic and clinical characteristics, among only older adults with MS. Method: The …

Hip And Knee Joint Angle Patterns And Kicking Velocity In Female And Male Professional Soccer Players: A Principal Component Analysis Of Waveforms Approach, Archit Navandar, Kristof Kipp, Enrique Navarro

Exercise Science Faculty Research and Publications

This study used principal component analysis (PCA) of waveforms to extract movement patterns from hip and knee angle time-series data; and determined if the extracted movement patterns were predictors of ball velocity during a soccer kick. Twenty-three female and nineteen male professional soccer players performed maximal effort instep kicks while motion capture and post-impact ball velocities data were recorded. Three-dimensional hip and knee joint angle time-series data were calculated from the beginning of the kicking leg’s backswing phase until the end of the follow-through phase and entered into separate PCAs for females and males. Three principal components (PC) (i.e., movement …

Muscle Force Contributions To Ankle Joint Contact Forces During An Unanticipated Cutting Task In People With Chronic Ankle Instability, Hoon Kim, Rianna M. Palmieri-Smith, Kristof Kipp

Exercise Science Faculty Research and Publications

The purpose of this study was to compare muscle force contributions to ankle joint compression and anteroposterior shear forces between people with chronic ankle instability (CAI) and healthy controls (CON) during an unanticipated cutting task. Eleven people with CAI and 11 CON performed an unanticipated cutting task as three-dimensional motion capture, ground reaction force (GRF), and muscle activation data were collected. A musculoskeletal modeling was used to calculate talocrural joint compression and anteroposterior shear forces and parse out the contributions to these forces from ankle-spanning muscles and from GRF. Independent t-tests were used for statistical analysis. People with CAI exhibited …

Navigator Role For Promoting Adaptive Sports And Recreation Participation In Individuals With Disabilities, Moriah Iverson, Alexander V. Ng, Alice F. Yan, Kimberley Zvara, Michael Bonk, Deb Falk-Palec, Cherri Sylla, Maurine Strickland, Rachel Preston, Diane W. Braza

Exercise Science Faculty Research and Publications

Objective

The aims of the study were to gain a better understanding of the resources, barriers, and facilitators of participation in adaptive sport and recreational activities as a means of achieving physical activity recommendations in individuals with disability and to understand preferences for a patient navigator service to help mitigate the barriers.

Design

Clinical, academic, and community stakeholders applied a community-engaged research approach to develop online surveys and focus group questions for adults with a disability or parents of a child with a disability to meet study objectives.

Results

One hundred ninety-eight adults and 146 parents completed the online surveys. …

Influence Of The Bar Position On Joint-Level Biomechanics During Isometric Pulling Exercises, Nayun Ahn, Hoon Kim, John Krzyszkowski, Stuart Roche, Kristof Kipp

Exercise Science Faculty Research and Publications

The purpose of this study was to investigate the influence of the bar position on ankle, knee, and hip net joint moments (NJMs), relative muscular effort (RME), and vertical ground reaction forces (GRFs) during isometric pulling exercises, such as the isometric midthigh pull. Eight female lacrosse athletes performed maximal effort isometric pulls at 3 different bar positions (low: above patella, mid: midthigh, and high: crease of hip) while motion capture and GRF data were recorded. Net joint moments were calculated with inverse dynamics. Relative muscle effort was defined as the ratio between the inverse dynamics NJMs and the maximum theoretical …

Prediction Of Throwing Distance In The Men’S And Women’S Javelin Final At The 2017 Iaaf World Championships, John Krzyszkowski, Kristof Kipp

Exercise Science Faculty Research and Publications

The purpose of this study was to use regularised regression models to identify the most important biomechanical predictors of throwing distance in elite male (M) and female (F) javelin throwers at the 2017 IAAF world championships. Biomechanical data from 13 male and 12 female javelin throwers who competed at the 2017 IAAF world championships were obtained from an official scientific IAAF report. Regularised regression models were used to investigate the associations between throwing distance and release parameters, whole-body kinematic and joint-level kinematic data. The regularised regression models identified two biomechanical predictors of throwing distances in both M and F javelin …

Hip Moment And Knee Power Eccentric Utilisation Ratios Determine Lower-Extremity Stretch-Shortening Cycle Performance, Kristof Kipp, John Krzyszkowski, Jordi Heeneman

Exercise Science Faculty Research and Publications

The eccentric utilisation ratio (EUR) is calculated as the ratio between countermovement jump (CMJ) and squat jump (SJ) heights, and is an indicator of lower-extremity stretch-shortening cycle (SSC) performance in athletes. Joint-based EUR can also be calculated but have never been reported. The purpose of this study was to investigate whether jump height-based (JH-based) EUR can be predicted by joint-specific EUR. Nine NCAA Division I college athletes (age: 21 ± 1 year, height: 1.75 ± 0.15 m, mass: 71 ± 20 kg) performed three SJ and CMJ. During all jumps, kinematic and kinetic data were obtained and used to calculate …

Sex Differences In Fatigability Following Exercise Normalised To The Power–Duration Relationship, Paul Ansdell, Jacob Skarabot, Elliott Atkinson, Sarah Corden, Amber Tygart, Kristy M. Hicks, Kevin Thomas, Sandra K. Hunter, Glyn Howatson, Stuart Goodall

Exercise Science Faculty Research and Publications

Due to morphological differences, females demonstrate greater fatigue resistance of locomotor muscle during single-limb and whole-body exercise modalities. Whilst females sustain a greater relative intensity of single-limb, isometric exercise than males, limited investigation has been performed during whole-body exercise. Accordingly, this study established the power–duration relationship during cycling in 18 trained participants (eight females). Subsequently, constant-load exercise was performed at critical power (CP)-matched intensities within the heavy and severe domains, with the mechanisms of fatigability assessed via non-invasive neurostimulation, near-infrared spectroscopy and pulmonary gas exchange during and following exercise. Relative CP (72 ± 5 vs. 74 ± 2% P …

Who Is Wearing A Mask? Gender-, Age-, And Location-Related Differences During The Covid-19 Pandemic, Mike Haischer, Rachel Beilfuss, Meggie Rose Hart, Lauren Opielinski, David Wrucke, Gretchen Zirgaitis, Toni D. Urich, Sandra K. Hunter

Exercise Science Faculty Research and Publications

Masks are an effective tool in combatting the spread of COVID-19, but some people still resist wearing them and mask-wearing behavior has not been experimentally studied in the United States. To understand the demographics of mask wearers and resistors, and the impact of mandates on mask-wearing behavior, we observed shoppers (n = 9935) entering retail stores during periods of June, July, and August 2020. Approximately 41% of the June sample wore a mask. At that time, the odds of an individual wearing a mask increased significantly with age and was also 1.5x greater for females than males. Additionally, the …