About

Jay Hertel is the Joe H. Gieck Professor of Sports Medicine and chair of the Department of Kinesiology at the University of Virginia. He also holds an academic appointment in the Department of Orthopaedic Surgery as a courtesy and is co-director of the Exercise & Sport Injury Lab. His research interests are at the intersection of lower extremity injury prevention and rehabilitation, clinical biomechanics, and athlete monitoring techniques aimed at improving the health and wellness of athletes and other physically active individuals. Dr. Hertel has authored or co-authored over 300 peer-reviewed journal articles and has presented at numerous national and international sports medicine conferences. He is a fellow of the American College of Sports Medicine, the National Athletic Trainers' Association, and the National Academy of Kinesiology.

Research topics

• Physical therapy
• Medicine
• Physical medicine and rehabilitation
• Surgery
• Internal medicine
• Mathematics
• Anatomy
• Statistics
• Gerontology
• Physics
• Demography

Selected publications

• Comparison of intrinsic foot muscle function in patients with different lower extremity conditions

  PLoS ONE · 2025-08-21 · 2 citations

  articleOpen accessCorresponding

  BACKGROUND: The intrinsic foot muscles (IFM), or foot core, provides stability to the foot skeleton. IFM dysfunction has been linked to foot and ankle injuries; however, the functional assessment of IFM in lower extremity conditions remains a clinical conundrum. We undertook a large study to understand the differences in muscle size and quality of IFM across a spectrum of conditions including Chronic Ankle Instability (CAI), Patellofemoral Pain (PFP), 1st Metatarsophalangeal Joint (1st MTPJ) arthrodesis and in patients with diabetes. This study compares IFM morphology and tissue quality in patients across these conditions and healthy control group individuals. METHODS: This study included 119 participants: 35 PFP, 29 CAI, 8 with 1st MTPJ arthrodesis, 9 with Diabetes, and 38 healthy controls. Ultrasound imaging (USI) assessed cross-sectional area (CSA) for muscle size and echogenicity for muscle quality in the Abductor Hallucis (AbH) and Flexor Digitorum Brevis (FDB). All size measures were normalized to body mass. Analysis of Coavariance (ANCOVA) was performed between groups, controlling for age and sex, to identify differences. RESULTS: Significant differences (P < 0.05) in the CSA of the AbH were found between all pathology groups and healthy control group, except for the 1st MTPJ group. CSA of FDB showed significant differences (P < 0.01) in all groups except the PFP and 1st MTPJ groups. For echogenicity, significant differences (P < 0.05) were found between groups for both AbH and FDB, while CAI, 1st MTPJ, and PFP groups showed higher FDB echogenicity. Large effect sizes were found for CSA and echogenicity in all groups except PFP. CONCLUSION: This is the first study to our knowledge to collectively analyze multiple clinical groups with suspected IFM weakness in functional position for both muscle size and quality. Significant changes in muscle size and quality were observed, suggesting that clinicians should assess and target IFM rehabilitation to improve foot and ankle function in these populations.

  PublisherOA PDFDOI

• A Comparison Between a Foot Intrinsic Rehabilitation Exercise Protocol and the Standard of Care on Pain Intensity Levels Among Participants with Chronic Ankle Instability: A Multi-Site Randomized Control Trial

  Journal of Pain · 2025-04-01

  article
  PublisherDOI

• Effects of step rate based gait training on running biomechanics: A systematic review and meta-analysis

  Gait & Posture · 2025-10-11

  reviewSenior author
  PublisherDOI

• Rehabilitation Exercises And Minimalist Shoes Strengthen Intrinsic Foot Muscles In Adults With Plantar Fasciopathy

  Medicine & Science in Sports & Exercise · 2025-09-16 · 1 citations

  article

  The plantar fascia and the intrinsic foot muscles (IFM) provide stability to the foot, yet individuals with plantar fasciopathy (PF) have reduced intrinsic foot muscle (IFM) strength. Several studies have shown that IFM strengthening, via exercises or wearing minimalist shoes, leads to reduced pain in individuals with PF, but few studies have investigated changes in IFM strength. PURPOSE: The purpose of this study was to investigate the effects of an 8-week intervention of exercise and wearing minimalist shoes (MS), compared to only exercise, on IFM strength of the painful foot in adults with PF. METHODS: Thirty-three individuals with PF were randomized into an exercise plus MS group (n = 17, 12 female) or exercise only control group (n = 16, 11 female). IFM strength was assessed at baseline and follow-up with a handheld dynamometer, in a hook lying position on a treatment table with toes off the table. Participants were instructed to push down on the transducer with the great and lesser toes, separately. Maximal isometric contraction was recorded in Newtons. Participants were instructed in home exercises including massage ball myofascial release, toes-elevated calf raises, and calf and foot stretches. Participants in the MS group were also instructed to wear MS daily with progressing daily wear time throughout the intervention. Repeated measures ANOVAs evaluated the interaction of group and time on IFM strength, with Tukey’s HSD post-hoc testing when appropriate. α = 0.05 for all analyses. RESULTS: Participants had similar baseline characteristics (age: 39.7 ± 12.0, height: 167 cm ± 8.71, weight: 77.1 kg ± 13.1). There were significant time main effects for great toe IFM strength (p < 0.001; control: baseline 86.33 N ± 46.21, follow-up 112.82 N ± 45.22; MS: baseline 73.77 N ± 30.71, follow up 100.06 N ± 37.18) and lesser toe IFM strength (p < 0.001; control: baseline 74.36 N ± 38.06, follow-up 96.43 N ± 35.41; MS: baseline 57.09 N ± 26.78, follow-up 78.97 N ± 27.57), but no between group differences. CONCLUSIONS: Performing rehabilitation exercises with or without wearing MS led to improved IFM strength, potentially indicating that individuals with PF can increase function alongside decreases in pain. Although adding MS did not produce superior strength gains, individuals with PF may wear MS if desired without any adverse effects. Supported by: This study has been funded by the Xero Shoes Minimal Footwear Research Grant through ACSM

  PublisherDOI

• The Effect Of Home Rehabilitation Exercises And Minimalist Shoes On Impact Forces And Pain

  Medicine & Science in Sports & Exercise · 2025-09-16

  article

  Plantar fasciopathy (PF) occurs when the plantar fascia is mechanically overloaded due to increased weight or activity, leading to foot pain while weight-bearing. Impact forces (IF) at initial contact while walking are decreased in individuals with PF compared to healthy individuals, likely due to pain. Interventions to strengthen the foot such as rehabilitation or wearing minimalist shoes (MS) have been prescribed for PF, but it is unknown how they affect gait and whether pain plays a role. PURPOSE: To investigate the effects of 8 weeks of exercise and wearing minimalist shoes on IF at initial contact while walking in individuals with PF, and to determine if the changes are influenced by pain. METHODS: Twelve individuals (n = 9 female) with unilateral PF who underload the injured limb (1.05 N ± 0.09) compared to the healthy limb (1.18 N ± 0.07) volunteered for this study (age: 46.1 ± 10.4, height: 166 ± 9.15, weight: 74.7 ± 8.86). Participants recorded their average first-step pain over the past week using a 100 mm visual analog scale. Participants walked on a treadmill at a self-selected pace with force-sensing insoles in their conventional shoes of choice at both baseline and follow-up. Peak IF were measured and normalized to body weight (% BW). Participants wore MS with progressing daily wear time during the intervention, and were instructed in home rehabilitation exercises including massage ball myofascial release, toes elevated calf-raises, calf and foot stretches. Changes in pain and IF symmetry over time were assessed using t-tests. Linear regression was used to evaluate the association between changes in pain and IF symmetry from baseline to follow-up. RESULTS: From baseline to follow-up there were no significant changes in IF symmetry (p = 0.46, baseline: 88.80% ± 6.06, follow-up: 90.63% ± 9.89). Decrease in pain was significant (p < 0.001, baseline: 49.30 mm ± 15.40, follow-up: 23.50 mm ± 16.80) and significantly predicted change in symmetry (p < 0.001, adjusted R2 = 0.77, B = -0.49), showing that every 1 unit decrease in pain led to a 0.49% increase in peak IF symmetry. CONCLUSION: Individuals with PF did not experience significant changes in symmetry of IF, after 8 weeks of exercise and minimalist shoes. However, increases in symmetry and decreases in pain levels were highly related. Supported by: Xero Shoes' Minimal Footwear Research Grant

  PublisherDOI

• Gait Biomechanics Among Female Endurance Runners: Comparing Days With and Without Menstrual Cycle–Related Symptoms

  Journal of Athletic Training · 2025-05-29 · 1 citations

  articleOpen accessSenior author

  OBJECTIVE: Determine differences in running biomechanics in female endurance runners between days when they did and did not report menstrual cycle-related symptoms. METHODS: Observational study. Subjects were provided RunScribe sensors to attach to their shoes to collect biomechanical data when running. Daily during the study period, subjects were sent a text message to complete a survey asking about their wellness, menstrual status, and training status. Descriptive measures (mean ± SD) were generated for whether runners reported being asymptomatic or symptomatic during runs and run workout details. Paired sample t-tests were executed to identify differences in impact Gs, braking Gs, pronation excursion, maximum pronation velocity, foot strike type, and gait speed between runs on days participants reported having menstrual-related symptoms (symptomatic) or not (asymptomatic). Participants needed to have recorded runs spanning the entire data collection window to be included for comparative analyses. RESULTS: Twenty-seven university club runners (age 20.5 ± 1.5) participated in the study. All runners (n = 27) experienced at least one menstrual cycle-related symptom during data collection. The average number of asymptomatic runs was 22.3 ± 17.1 and symptomatic runs was 9.1 ± 7.5. Daily mileage averaged 4.3 ± 1.9 miles and total mileage was 154.2 ± 115.4 miles. Fourteen runners had run data viable for pairwise sampling. There was no significant difference in biomechanical measures between symptomatic or asymptomatic days (p > .05). CONCLUSION: This study prospectively monitored distance runners' activity while simultaneously recording symptoms related to the menstrual cycle. While runners reported fewer days running when symptomatic, we did not identify a difference in objective biomechanical measures between asymptomatic or symptomatic runs. Perceived symptom burden was present in this sport population and may warrant further exploration of perceived expectations of the menstrual cycle to athletic performance.

  PublisherOA PDFDOI

• Plantar Fasciopathy Pain Correlates With Time Between Peaks Symmetry But Not Intrinsic Foot Muscle Strength

  Medicine & Science in Sports & Exercise · 2025-09-16

  article
  PublisherDOI

• Intrinsic foot muscles size and quality changes after impairment-based rehabilitation in patients with chronic ankle instability

  Physical Therapy in Sport · 2025-05-17 · 3 citations

  article
  PublisherDOI

• Acute Changes in Sleep Stages After Concussion in Collegiate Athletes: A Pilot Study

  Journal of Athletic Training · 2025-05-13 · 2 citations

  articleOpen access

  CONTEXT: Sleep has been suggested to be a modifier of recovery following a concussion and is associated with greater symptomatology and number of days until symptom resolution. However, the physiological mechanism for why sleep disturbances occur remains poorly understood. Alterations in time spent in stages of a sleep cycle following a concussion may contribute to recovery. OBJECTIVE: The purpose of our study was to use a non-invasive, sensor-derived measure of sleep stages to determine differences between collegiate athletes with or without a concussion, acutely following injury (<72 hours). DESIGN: Case-control. SETTING: Division 1 collegiate athletics. PARTICIPANTS: Division 1 Collegiate athletes diagnosed with a concussion were compared to healthy-matched controls based on health history, demographics and sport. INTERVENTIONS: Individuals in both groups were provided with and instructed to wear an OURA ring actigraphy device, nightly, within 72 hours of their concussion. MAIN OUTCOME MEASURES: Differences in sensor-derived time spent in Light, Deep, rapid eye- movement (REM) sleep, time awake, and total sleep time between groups. RESULTS: A total of 18 athletes were included in our analyses (9 concussed, 9 controls) with an average age of 19.3+ 1.3 years. Individuals with a concussion spent less time in deep sleep (113.1±33.1 vs 134.4±51.1 minutes, p=0.03), and more time awake (90.22±30.0 vs 49.28±11.5 minutes, p=0.02) compared to individuals without a concussion. No significant differences were found for time spent in total sleep time, Light or REM sleep. CONCLUSION: Acutely following concussion, individuals may demonstrate changes in sleep stages. Our results suggest that time spent in different stages of sleep may be a potential mechanism underlying recovery from concussion. Our results provide an important step in using wearable sensors to better understand sleep disturbances following concussion to help mitigate risk of a prolonged recovery.

  PublisherOA PDFDOI

• Plantar pressure analysis of different orthoses in patients after first metatarsophalangeal joint arthrodesis

  Prosthetics and Orthotics International · 2024-04-18 · 1 citations

  articleSenior author

  BACKGROUND: There is no gold standard for a walking orthosis after first metatarsophalangeal joint (MTPJ) arthrodesis surgery. Evaluation of plantar pressure measures and patient perceptions for different orthoses may assist surgeons to choose a postsurgery orthotic. The purpose of this study was to measure plantar pressure under the distal first ray during walking and patient perceptions of comfort, stability, and preference with 4 different orthoses in patients with a history of first MTPJ arthrodesis. METHODS: Crossover study in a university laboratory. Eleven patients volunteered (8 female, 3 male, age = 59.4 ± 9.1 years, 21.9 ± 17.5 months since surgery) who had a unilateral first MTPJ arthrodesis procedure more than 6 months before study participation. Four orthosis conditions were evaluated in all participants: patient's shoe, carbon fiber insert, OrthoWedge, and Post-Op Shoe. We analyzed peak plantar pressure and pressure-time integral under the whole foot and the distal first ray as well as recorded subjective rating for comfort and stability. Rank ordered for preferred orthosis. RESULTS: OrthoWedge had significantly lower whole-foot and distal first ray peak pressure than the other conditions. The pressure-time integral for the OrthoWedge was significantly less than the Carbon Fiber Insert and Post-Op Shoe. For stability, comfort, and condition preference, the OrthoWedge was ranked lowest among the 4 conditions. CONCLUSIONS: The OrthoWedge generated the lowest peak plantar pressure but was subjectively ranked as the least preferred orthosis. This discrepancy between objective biomechanical and subjective comfort measures must be weighed as surgeons prescribe an orthosis to patients after first MTPJ arthrodesis.

  PublisherDOI

Recent grants

• NIH Grant R21AT004195

  NIH · $403k · 2012

Frequent coauthors

• Joseph M. Hart

  146 shared

• Susan Saliba

  University of Virginia

  125 shared

• James A. Oñate

  121 shared

• Nelson Cortés

  Université Paris-Saclay

  114 shared

• Bonnie Van Lunen

  112 shared

• James Borchers

  The Ohio State University Wexner Medical Center

  70 shared

• Xueliang Pan

  The Ohio State University

  70 shared

• Cambrie Starkel

  70 shared

Labs

• Exercise and Sport Injury LaboratoryPI

Education

• PhD, Kinesiology

  Pennsylvania State University

  1999

• MEd. - Athletic Training

  University of Virginia

  1994

• BS Physical Education/Athletic Training

  University of Wisconsin La Crosse

  1993

Awards & honors

• Fellow of the American College of Sports Medicine
• Fellow of the National Athletic Trainers' Association
• Fellow of the National Academy of Kinesiology