Recreational Therapy 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 …

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 …

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 …

“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, …

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 …

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. …

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 …

Time-Frequency Analysis Of Muscle Activation Patterns In People With Chronic Ankle Instability During Landing And Cutting Tasks, Hoon Kim, Rianna M. Palmieri-Smith, Kristof Kipp

Exercise Science Faculty Research and Publications

Background

People with chronic ankle instability (CAI) exhibit neuromuscular deficits. Previous studies, however, only investigated magnitudes of muscle activation and not the time-frequency domain.

Research question

Do people with CAI exhibit differences in muscle activation patterns in the time-frequency domain during landing, anticipated cutting, and unanticipated cutting compared to matched controls?

Methods

Eleven people with CAI and eleven healthy matched controls (CON) performed landing, anticipated cutting, and unanticipated cutting as surface EMG of the lateral gastrocnemius, medial gastrocnemius, fibularis longus, soleus, and tibialis anterior were recorded. The time-frequency domain of surface EMG data was analyzed with wavelet transformations and principal …

Exercise And Lifestyle Physical Activity Recommendations For People With Multiple Sclerosis Throughout The Disease Course, Rosalind Kalb, Theodore R. Brown, Susan Coote, Kathleen Costello, Ulrik Dalgas, Eric Garmon, Barbara Geisser, June Halper, Herb Karpatkin, Jennifer Keller, Alexander V. Ng, Lara A. Pilutti, Amanda Rohring, Paul Van Asch, Kathleen Zachowski, Robert W. Motl

Exercise Science Faculty Research and Publications

Objectives:

To provide clinicians who treat multiple sclerosis (MS) patients with evidence-based or expert opinion–based recommendations for promoting exercise and lifestyle physical activity across disability levels.

Methods:

The National MS Society (“Society”) convened clinical and research experts in the fields of MS, exercise, rehabilitation, and physical activity to (1) reach consensus on optimal exercise and lifestyle physical activity recommendations for individuals with MS at disability levels 0–9.0 on the Expanded Disability Status Scale (EDSS) and (2) identify and address barriers/facilitators for participation.

Recommendations:

Based on current evidence and expert opinion, the Society makes the following recommendations, endorsed by the Consortium …

Impaired Firing Behavior Of Individually Tracked Paretic Motor Units During Fatiguing Contractions Of The Dorsiflexors And Functional Implications Post Stroke, Francesco Negro, Kathleen Bathon, Jennifer Nguyen, Cassidy Bannon, Claudio Orizio, Sandra K. Hunter, Allison S. Hyngstrom

Exercise Science Faculty Research and Publications

Introduction: This study quantified stroke-related changes in the following: (1) the averaged discharge rate of motor units (individually tracked and untracked) identified from high-density electromyography (HD-EMG) recordings, (2) global muscle EMG properties of the dorsiflexors during a fatiguing contraction, and the relationship between task endurance and measures of leg function.

Methods: Ten individuals with chronic stroke performed a sustained sub-maximal, isometric, fatiguing dorsiflexion contraction in paretic and non-paretic legs. Motor-unit firing behavior, task duration, maximal voluntary contraction strength (MVC), and clinical measures of leg function were obtained.

Results: Compared to the non-paretic leg, the paretic leg task duration was shorter, …

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 …

Greater Fatigue Resistance Of Dorsiflexor Muscles In People With Prediabetes Than Type 2 Diabetes, Jonathon Senefeld, Lynette A. Singh-Peters, Kenji A. Kenno, Sandra K. Hunter, Jennifer M. Jakobi

Exercise Science Faculty Research and Publications

Although exercise can prevent progression to T2D among people with prediabetes, little is known about fatigue during exercise in people with prediabetes compared to T2D. The purpose of the study was to compare the magnitude and mechanisms of fatigability of the ankle dorsiflexor muscles between people with prediabetes and T2D. Ten people with prediabetes (6 females, 51.7 ± 6.9 years) and fourteen with T2D (6 females, 52.6 ± 6.2 years) who were matched for age, body mass index and physical activity performed an intermittent (6 s contraction: 4 s relaxation) fatiguing task at 75% maximal voluntary contraction (MVC) with the …

Greater Fatigability And Motor Unit Discharge Variability In Human Type 2 Diabetes, Jonathon Senefeld, Kevin G. Keenan, Kevin S. Ryan, Sarah E. D'Astice, Francesco Negro, Sandra K. Hunter

Exercise Science Faculty Research and Publications

This study determined the discharge characteristics of motor units from two lower limb muscles before and after fatiguing exercise in people with type 2 diabetes (T2D) with no symptoms of polyneuropathy and activity-matched controls. Seventeen people with T2D (65.0 ± 5.6 years; 8 women) and 17 controls (63.6 ± 4.5 years; 8 women) performed: (a) intermittent, isometric contractions at 50% maximal voluntary isometric contraction (MVIC) sustained to failure with the ankle dorsiflexors, and (b) a dynamic fatiguing task (30% MVIC load) for 6 min with the knee extensors. Before and after the fatiguing tasks, motor unit characteristics (including coefficient of …

Ca2+ Dependency Of Limb Muscle Fiber Contractile Mechanics In Young And Older Adults, Laura E. Teigen, Christopher W. Sundberg, Lauren J. Kelly, Sandra K. Hunter, Robert H. Fitts

Exercise Science Faculty Research and Publications

Age-induced declines in skeletal muscle contractile function have been attributed to multiple cellular factors, including lower peak force (P_o), decreased Ca²⁺ sensitivity, and reduced shortening velocity (V_o). However, changes in these cellular properties with aging remain unresolved, especially in older women, and the effect of submaximal Ca²⁺ on contractile function is unknown. Thus, we compared contractile properties of muscle fibers from 19 young (24 ± 3 yr; 8 women) and 21 older adults (77 ± 7 yr; 7 women) under maximal and submaximal Ca²⁺ and assessed the abundance of three proteins thought to …

Determinants Of Low Bone Mineral Density In People With Multiple Sclerosis: Role Of Physical Activity, Brice T. Cleland, Paula E. Papanek, Benjamin A. Ingraham, April L. Harkins, Mauricio Garnier-Villarreal, Douglas Woo, Mary Ellen Csuka, Alexander V. Ng

Exercise Science Faculty Research and Publications

Background

People with multiple sclerosis (PwMS) have reduced bone mineral density (BMD), but the causes are unclear. Some factors that may cause reduced BMD in PwMS have been understudied, including physical activity, inflammation, cortisol, symptomatic fatigue, and depression. The aim of this study was to investigate factors that may uniquely contribute to reduced BMD in PwMS as compared to people without MS. We hypothesized that physical activity would be the primary determinant of low BMD in PwMS, with additional contributions from inflammation and sympathetic nervous system activation.

Methods

We tested 23 PwMS (16 women; median EDSS: 2) and 22 control …

Increased Cardiovascular Response To A 6-Minute Walk Test In People With Type 2 Diabetes, Jonathon Senefeld, Sarah E. D'Astice, Alison R. Harmer, Sandra K. Hunter

Exercise Science Faculty Research and Publications

Background and objective

Exercise is a cornerstone of management for type 2 diabetes; however, little is known about the cardiovascular (CV) response to submaximal functional exercise in people with type 2 diabetes. The aim of this study was to compare performance and CV response during a 6-minute walk test (6MWT) between people with type 2 diabetes and matched control subjects.

Methods

CV response and distance walked during the 6MWT were assessed in 30 people with type 2 diabetes, matched for age, body composition, physical activity, and estimated aerobic capacity with 34 control subjects (type 2 diabetes group: 16 men, 59.8 …

Efficacy Of Osteoporosis Prevention Smartphone App, Polly Ryan, Roger L. Brown, Mary Ellen Csuka, Paula E. Papanek

Exercise Science Faculty Research and Publications

Background

The Striving to be Strong study tested the efficacy of a multifaceted, theory-based, complex osteoporosis prevention smartphone application (app). We hypothesized use of the app would improve bone mineral density and trabecular bone scores.

Methods

The study was a three-group, prospective, repeated-measure, longitudinal randomized trial. Baseline sample consisted of 290 healthy women between 40 and 60 years of age. Participants were randomly assigned to one of three groups: “Striving,” a dynamically tailored, person-centered app; “Boning Up,” a standardized osteoporosis-education e-book; and “Wait List,” a participant’s choice of intervention in the final 3 months of the 12-month study. Participants had …

Feasibility And Acceptability Of A Self-Report Activity Diary In Families Of Children With And Without Special Needs, Bethany Forseth, Paula E. Papanek, Linda Bandini, Dale A. Schoeller, Andrea Moosreiner, Kathleen J. Sawing, Kimberley Zvara, Michael Fendrich, Michele Polfuss

Exercise Science Faculty Research and Publications

This study was conducted to examine the feasibility and acceptability of a self-report activity diary completed by parents and older children to assess the child's daily activity in children with and without special needs. The study included 36 child/parent dyads stratified by child age and diagnosis. Parents (n = 36) and children ≥13 years (n = 12) were asked to report on the child's daily activity using an activity diary. Feasibility was determined based on successfully returned diaries and acceptability via post-study interview. Activity diaries were submitted by 94% of the parents and 100% of the children, with 83% and …

Sex Differences In Fatigability And Recovery Relative To The Intensity–Duration Relationship, Paul Ansdell, Paul Ansdell, Callum G. Brownstein, Jakob Škarabot, Kristy M. Hicks, Glyn Howatson, Kevin Thomas, Sandra K. Hunter, Stuart Goodall

Exercise Science Faculty Research and Publications

Females are less fatigable than males during isometric exercise at intensities relative to maximal voluntary contraction (MVC); however, whether a sex difference in fatigability exists when exercise is prescribed relative to a critical intensity is unknown. This study established the intensity–duration relationship, and compared fatigability and recovery between sexes following intermittent isometric contractions normalised to critical intensity. Twenty participants (10 females) completed four intermittent isometric knee extension trials to task failure to determine critical intensity and the curvature constant (W′), followed by fatiguing tasks at +10% and −10% relative to critical intensity. Neuromuscular assessments were completed at baseline …

Differential Effects Of Aging And Physical Activity On Corticospinal Excitability Of Upper And Lower Limb Muscles, Vianney Rozand, Jonathon William Senefeld, Christopher W. Sundberg, Ashleigh E. Smith, Sandra K. Hunter

Exercise Science Faculty Research and Publications

Corticospinal tract excitability can be altered by age, physical activity (PA), and possibly sex, but whether these effects differ between upper and lower limb muscles is unknown. We determined the influence of age, PA, and sex on corticospinal excitability of an upper limb and a lower limb muscle during submaximal contractions by comparing stimulus-response curves of motor evoked potentials (MEPs). Transcranial magnetic stimulation (TMS) was used to evoke stimulus-response curves in active muscles by incrementally increasing the stimulator intensity from below the active motor threshold (AMT) until a plateau in MEP amplitudes was achieved. Stimulus-response curves were analyzed from the …