Low-frequency electrically induced exercise after spinal cord injury: Physiologic challenge to skeletal muscle and feasibility for long-term use.

CONTEXT: Skeletal muscle has traditionally been considered a "force generator": necessary for purposes of locomotion, but expendable for non-ambulators who use wheelchairs, such as people with a spinal cord injury (SCI). Active skeletal muscle plays an indispensable role in regulating systemic metabolic functions, even in people with paralysis, but because of severe osteoporosis, high tetanic muscle forces induced with high frequency electrical stimulation may be risky for some individuals. The purpose of this study was to compare the physiologic muscle properties incurred by two low force/low frequency repetitive stimulation protocols (1 and 3 Hz); and, to assess the acceptability of each protocol among people with SCI. METHODS: Ten individuals with chronic SCI (12.9 years) and 11 individuals without SCI (NonSCI) participated in the study. Participants received either 1 or 3 Hz stimulation to the quadriceps muscle on Day 1, then the converse on Day 2. Each session consisted of 1000 stimulus pulses. RESULTS: The initial and maximum forces were similar for the 1 and 3 Hz frequencies. The fatigue index (FI) for SCI and NonSCI groups were lower (P < 0.007) for 3 Hz than for 1 Hz (0.34 ± 0.17 versus 0.65 ± 0.16 and 0.72 ± 0.14 versus 0.87 ± 0.07, respectively). CONCLUSION: The 3 Hz stimulation offered the greatest physiological challenge and was perceived as more acceptable for long term use among people with SCI.

Psychometric Analysis of an Integrated Clinical Education Tool for Physical Therapists.

INTRODUCTION: Integrated clinical education (ICE) courses require opportunities for practice, assessment of performance, and specific feedback. The purposes of this study were to 1) analyze the internal consistency of a tool for evaluating students during ICE courses, 2) examine the responsiveness of the tool between midterm and final assessments, and 3) develop a model to predict the final score from midterm assessments and explore relationships among the 6 domains. REVIEW OF LITERATURE: Several clinical education assessment tools have been developed for terminal clinical experiences, but few have focused on the needs of learners during the ICE. SUBJECTS: Eighty-five student assessments were collected from 2 consecutive cohorts of physical therapist students in a first full-time ICE course. METHODS: The tool contained 29 items within 6 domains. Items were rated on a 5-point scale from dependent to indirect supervision. Cronbach's alpha was used to analyze the internal consistency of the tool, whereas responsiveness was examined with paired t-test and Cohen's d. A best subsets regression model was used to determine the best combination of midterm variables that predicted the final total scores. Coefficients of determination (R2) were calculated to explore the relationships among domains. RESULTS: The tool was found to have high internal consistency at midterm and final assessment (α = 0.97 and 0.98, respectively). Mean scores increased over time for each domain score and for the total score (P < .001; d = 1.5). Scores in 3 midterm domains predicted more than 57% of the variance in the final total score. DISCUSSION AND CONCLUSION: Results support the use of this tool to measure student performance and growth in a first full-time ICE course. Targeted measurement of students' abilities in ICE courses assists with differentiating formative and summative learning needed to achieve academic success.

National Benchmarks to Understand how Doctor of Physical Therapy Learners from Minoritized Race and Ethnicity Groups Perceive their Physical Therapist Education Program.

OBJECTIVE: The demographic homogeneity of the physical therapist workforce and its educational pathway may undermine the profession's potential to improve the health of society. Building academic environments that support the development of all learners is fundamental to building a workforce to meet societal health care needs. The Benchmarking in Physical Therapy Education study uses the Physical Therapy Graduation Questionnaire to comprehensively assess learner perceptions of the physical therapist academic environment. The present report examined whether racial and ethnic minoritized (REM) physical therapist learners perceive their Doctor of Physical Therapy (DPT) education differently from their non-REM peers. METHODS: Five thousand and eighty graduating DPT learners in 89 institutions provided demographic data and perceptions of a range of learning environment domains. Analyses included REM versus non-REM comparisons as well as comparisons among individual race and ethnicity groups. RESULTS: Compared to their non-minoritized peers, REM respondents expressed less satisfaction with their education and lower confidence in their preparedness for entry-level practice. REM respondents observed more faculty professionalism disconnects and demonstrated less agreement that their program had fostered their overall psychological well-being. REM respondents experienced higher rates of mistreatment than their peers and reported higher rates of exhaustion and disengagement, the 2 axes of academic burnout. Black/African American and Hispanic/Latino/a/x (Hispanic, Latino, Latina, and/or Latinx) respondents incurred significantly more educational debt than Asian and White respondents. REM respondents reported greater empathy and greater interest in working in underserved communities. CONCLUSION: REM respondents perceived the physical therapist learning environment more negatively than their non-minoritized peers but expressed strong interest in serving people from underserved communities. These national benchmarks offer academic institutions the opportunity to self-assess their own environment and to work to improve the quality of the educational experience for all learners. IMPACT: In a nationwide benchmarking study, learners from minoritized race and ethnicity backgrounds reported more negative experiences and outcomes during physical therapist education than their non-minoritized peers. These same learners demonstrated high empathy and interest in serving people from underserved (under-resourced) communities. Learning environments that permit all individuals to thrive may be an essential avenue to improve the health of a rapidly diversifying society.

Tolerance for Ambiguity: Correlations With Medical and Physical Therapy Student Traits and Experiences Within the Learning Environment.

PURPOSE: Health care professions trainees and clinicians who perceive ambiguous situations as sources of threat (low tolerance for ambiguity [TFA]) experience greater risk for mental health disorders and professional burnout. Physical therapists likely encounter substantial ambiguity because of the biopsychosocial nature of their main therapeutic strategies. The purpose of this study was to identify student traits and experiences within the learning environment that differentiate students with high and low TFA for medicine and physical therapy (PT), and to identify areas of interprofessional overlap and distinction. METHOD: Graduation Questionnaire survey data from graduating PT (n = 2,727) and medical students (n = 33,159) from the 2019-2020 and 2020-2021 academic years were sorted according to student TFA score, and respondents in the highest and lowest TFA quartiles were retained for analysis. Difference-in-differences analysis was used to reduce the number of potential explanatory factors to a parimonious subset that was put into linear regression models. Inferential statistics were applied to all significant factors identified from the linear regression models. RESULTS: For both professions, higher TFA was generally associated with more positive ratings of the learning environment (student-faculty interactions, faculty professionalism, satisfaction with career choice), lower experiences of exhaustion and disengagement (the 2 axes of academic burnout), and higher scores for the empathy domain of perspective-taking. Uniquely for medical students, low TFA was associated with lower empathy scores and a lower degree of interest in working with underserved individuals. CONCLUSIONS: Findings suggest that for both professions, high TFA corresponded with better ratings of the educational experience and with traits that are advantageous for patient-centered practice and occupational resilience. Interventions to cultivate TFA among health care trainees may be an important way to meet the growing demand for humanistic health care professionals who are prepared to meet society's complex needs.

Neuromuscular and gene signaling responses to passive whole-body heat stress in young adults.

This study aimed to investigate whether acute passive heat stress 1) decreases muscle Maximal Voluntary Contraction (MVC); 2) increases peripheral muscle fatigue; 3) increases spinal cord excitability, and 4) increases key skeletal muscle gene signaling pathways in skeletal muscle. Examining the biological and physiological markers underlying passive heat stress will assist us in understanding the potential therapeutic benefits. MVCs, muscle fatigue, spinal cord excitability, and gene signaling were examined after control or whole body heat stress in an environmental chamber (heat; 82 °C, 10% humidity for 30 min). Heart Rate (HR), an indicator of stress response, was correlated to muscle fatigue in the heat group (R = 0.59; p < 0.05) but was not correlated to MVC, twitch potentiation, and H reflex suppression. Sixty-one genes were differentially expressed after heat (41 genes >1.5-fold induced; 20 < 0.667 fold repressed). A strong correlation emerged between the session type (control or heat) and principal components (PC1) (R = 0.82; p < 0.005). Cell Signal Transduction, Metabolism, Gene Expression and Transcription, Immune System, DNA Repair, and Metabolism of Proteins were pathway domains with the largest number of genes regulated after acute whole body heat stress. Acute whole-body heat stress may offer a physiological stimulus for people with a limited capacity to exercise.

Healthcare educational debt in the united states: unequal economic impact within interprofessional team members.

BACKGROUND: Advancing healthcare access and quality for underserved populations requires a diverse, culturally competent interprofessional workforce. However, high educational debt may influence career choice of healthcare professionals. In the United States, health professions lack insight into the maximum educational debt that can be supported by current entry-level salaries. The purpose of this interprofessional economic analysis was to examine whether average educational debt for US healthcare graduates is supportable by entry-level salaries. Additionally, the study explored whether trainees from minoritized backgrounds graduate with more educational debt than their peers in physical therapy. METHODS: The study modeled maximum educational debt service ratios for 12 healthcare professions and 6 physician specialties, incorporating profession-specific estimates of entry-level salary, salary growth, national average debt, and 4 loan repayment scenarios offered by the US Department of Education Office of Student Financial Aid. Net present value (NPV) provided an estimate for lifetime "economic power" for the modeled careers. The study used a unique data source available from a single profession (physical therapy, N = 4,954) to examine whether educational debt thresholds based on the repayment model varied between minoritized groups and non-minoritized peers. RESULTS: High salary physician specialties (e.g. obstetrics/gynecology, surgery) and professions without graduate debt (e.g. registered nurse) met debt ratio targets under any repayment plan. Professions with strong salary growth and moderate debt (e.g. physician assistant) required extended repayment plans but had high career NPV. Careers with low salary growth and high debt relative to salary (e.g. physical therapy) had career NPV at the lowest range of modeled professions. 29% of physical therapy students graduated with more debt than could be supported by entry-level salaries. Physical therapy students from minoritized groups graduated with 10-30% more debt than their non-minoritized peers. CONCLUSIONS: Graduates from most healthcare professions required extended repayment plans (higher interest) to meet debt ratio benchmarks. For several healthcare professions, low debt relative to salary protected career NPV. Students from minoritized groups incurred higher debt than their peers in physical therapy.

Exercise Prescription Principles among Physicians and Physical Therapists for Patients with Impaired Glucose Control: A Cross-Sectional Study.

Exercise confers a multitude of benefits with limited adverse side effects, making it a powerful "medication" for a plethora of diseases. In people living with uncontrolled glucose levels, exercise can be an effective "medication" to assist in the management of hyperglycemia. We sought to survey healthcare providers (physicians and physical therapists) to determine the current state of exercise recommendation for people with glucose control issues. Healthcare providers were surveyed from six academic medical centers in the Midwest to determine the recommended exercise parameters (type, frequency, duration, intensity, and timing) for patients with glucose control issues. Data from 209 practitioners who completed the survey were used for analysis. Chi-square tests were used to determine differences in exercise recommendations between physical therapists (PTs) and physicians (MD/DOs). PTs and MD/DOs recommended similar exercise parameters. Of all respondents, 78.9% recommended exercise to patients with glucose control issues. Respondents who considered themselves to be active exercisers were more likely to recommend exercise than those who were not exercisers. Only 6.1% of all respondents recommended post-meal exercise. Healthcare providers overwhelmingly recommended exercise for people with glucose control issues, but the "timing" is not congruent with best practice recommendations.

Impaired Glucose Tolerance and Visceral Adipose Tissue Thickness among Lean and Non-Lean People with and without Spinal Cord Injury.

After spinal cord injury (SCI), multiple adaptations occur that influence metabolic health and life quality. Prolonged sitting and inactivity predispose people with SCI to body composition changes, such as increased visceral adipose tissue (VAT) thickness, which is often associated with impaired glucose tolerance. Our goal is to understand whether VAT is an index of leanness, and, secondarily, whether mobility methods influence glucose tolerance for people living with SCI. A total of 15 people with SCI and 20 people without SCI had fasting oral glucose tolerance tests (OGTT) and VAT thickness (leanness) measured during a single session. Glucose was 51% and 67% greater for individuals with SCI relative to those without SCI after 60 and 120 min of an OGTT (p < 0.001). Glucose area under the curve (AUC) was 28%, 34%, and 60% higher for non-lean people with SCI than lean people with SCI and non-lean and lean people without SCI, respectively (p = 0.05, p = 0.009, p < 0.001). VAT was associated with glucose AUC (R2 = 0.23, p = 0.004). Taken together, these findings suggest that leanness, as estimated from VAT, may be an important consideration when developing rehabilitation programs to influence metabolism among people with SCI.

Longitudinal changes in white matter as measured with diffusion tensor imaging in adult-onset myotonic dystrophy type 1.

Myotonic dystrophy type 1 is characterized by neuromuscular degeneration. Our objective was to compare change in white matter microstructure (fractional anisotropy, radial and axial diffusivity), and functional/clinical measures. Participants underwent yearly neuroimaging and neurocognitive assessments over three-years. Assessments encompassed full-scale intelligence, memory, language, visuospatial skills, attention, processing speed, and executive function, as well as clinical symptoms of muscle/motor function, apathy, and hypersomnolence. Mixed effects models were used to examine differences. 69 healthy adults (66.2% women) and 41 DM1 patients (70.7% women) provided 156 and 90 observations, respectively. There was a group by elapsed time interaction for cerebral white matter, where DM1 patients exhibited declines in white matter (all p<0.05). Likewise, DM1 patients either declined (motor), improved more slowly (intelligence), or remained stable (executive function) for functional outcomes. White matter was associated with functional performance; intelligence was predicted by axial (r = 0.832; p<0.01) and radial diffusivity (r = 0.291, p<0.05), and executive function was associated with anisotropy (r = 0.416, p<0.001), and diffusivity (axial: r = 0.237, p = 0.05 and radial: r = 0.300, p<0.05). Indices of white matter health are sensitive to progression in DM1. These results are important for clinical trial design, which utilize short intervals to establish treatment efficacy.

Biomarkers for rapid H-reflex operant conditioning among females.

Operant conditioning of a spinal monosynaptic pathway using the Hoffman reflex (H-reflex) is well established in animal and human studies. There is a subset within the human population (∼20% nonresponders) who are unable to up train this pathway suggesting some distinct or unique identifying characteristics. Importantly, females, who have a nine times higher rate of injury during human performance activities than men, have been understudied in areas of CNS neuroplasticity. Our long-term goal is to understand if innate ability to rapidly up train the H-reflex is predictive of future performance-based injury among females. In this study, we primarily determined whether healthy, young females could rapidly increase the H-reflex within a single session of operant conditioning and secondarily determined if electro-physiological, humoral, cognitive, anthropometric, or anxiety biomarkers distinguished the responders from nonresponders. Eighteen females (mean age: 24) participated in the study. Overall, females showed a group main effect for up training the H-reflex (P < 0.05). Of the cohort, 10 of 18 females met the criteria for up training the H-reflex (responders). The responders showed lower levels of estradiol (P < 0.05). A multivariate stepwise regression model supported that extracellular to intracellular water ratio (ECW/ICW) and H-max/M-max ratio explained 60% of the variation in up training among females. These findings support that females can acutely upregulate the H-reflex with training and that electro-physiological and hormonal factors may be associated with the up training.NEW & NOTEWORTHY Young females who acutely increase their H-reflexes with operant conditioning had lower levels of estradiol. However, the best predictors of those who could up-train the H-reflex were baseline H-reflex excitability (H-max/M-max) and extracellular to intracellular water ratio (ECW/ICW). Future studies are warranted to understand the complex relationship between operant conditioning, human performance, and injury among active young females.

Multifractal Nonlinearity Moderates Feedforward and Feedback Responses to Suprapostural Perturbations.

An adaptive response to unexpected perturbations requires near-term and long-term adjustments over time. We used multifractal analysis to test how nonlinear interactions across timescales might support an adaptive response following an unpredictable perturbation. We reanalyzed torque data from 44 young and 24 older adults who performed a single-leg squat task challenged by an unexpected mechanical perturbation and a secondary visual-cognitive task. We report three findings: (a) multifractal nonlinearity interacted with pre-perturbation torque production and task error to presage greater pre-voluntary feedforward increases and greater voluntary reductions, respectively, in post-perturbation task error; (b) multifractal nonlinearity presaged relatively smaller task error than standard deviations of both pre-perturbation torques and pre-perturbation task error; and (c) increased task demand (e.g., age-related changes in dexterity and dual-task settings) led to multifractal nonlinearity presaging reduced task error. All these results were consistent with our expectations, except that a pre-perturbation knee torque-dependent increase in post-perturbation task error appeared later for older than for younger participants. This correlational multifractal modeling offered theoretical clarity on the possible roles of nonlinear interactions across timescales, moderating both feedforward and feedback processes, and presaging greater stability when the standard deviation is relatively large and task demands are strong. Thus, multifractal nonlinearity usefully describes movement variability even when paired with classical descriptors like the standard deviation. We discuss potential insights from these findings for understanding suprapostural dexterity and developing rehabilitative interventions.

Acute Low Force Electrically Induced Exercise Modulates Post Prandial Glycemic Markers in People with Spinal Cord Injury.

Regular exercise involves daily muscle contractions helping metabolize up to 70% of daily ingested glucose. Skeletal muscle increases glucose uptake through two distinct pathways: insulin signaling pathway and muscle contraction mediated AMPK pathway. People with paralysis are unable to contract their muscles which atrophy, transform into insulin resistant glycolytic muscle, and develop osteoporosis. Our goal is to determine if low force electrically induced exercise (LFE) will modulate the post prandial insulin and glucose response in people with and without spinal cord injury (SCI). 18 people with SCI and 23 without SCI (Non-SCI) participated in an assessment of metabolic biomarkers during passive sitting (CTL) and a bout of LFE delivered to the quadriceps/hamstring muscle groups after a glucose challenge. Baseline fasting insulin (p = 0.003) and lactate (p = 0.033) levels were higher in people with SCI, but glucose levels (p = 0.888) were similar compared to the non-SCI population. After 1-h of muscle contractions using LFE, heart rate increased (p < 0.001), capillary glucose decreased (p = 0.004), insulin decreased (p < 0.001), and lactate increased (p = 0.001) in the SCI population. These findings support that LFE attenuates certain metabolic blood biomarkers during a glucose challenge and may offer a lifestyle strategy to regulate metabolic responses after eating among people with SCI.

Sympathetic Vagal Balance and Cognitive Performance in Young Adults during the NIH Cognitive Test.

Compromised cognitive function is associated with increased mortality and increased healthcare costs. Autonomic nervous system arousal, as measured by an electrocardiogram (ECG), has received recent attention because of its association with the blood perfusion of brain regions involved with cognitive function. The purposes of this study were to determine whether the ECG HR variation, as measured by the standard deviation of the heart rate N-to-N intervals (SDNN), and sympathetic vagal tone, as estimated by the low-frequency/high-frequency ratio (LF/HF), are increased with cognitive performance during the NIH Cognitive Test (Picture Sequence, Dimensional Change Card Sort, Flanker, and List Sorting). A total of 62 young people without cognitive impairment participated in this study. We discovered that the ECG LF/HF ratio was increased in the top 50% of participants who could: (1) inhibit information and stay attentive to a desired task during the Flanker Test; (U = 329, p = 0.03; R2 = 0.76); and (2) promote cognitive function flexibility during the DCCS Test; (U = 55, p = 0.007; R2 = 0.98). Taken together, these findings support that the arousal level influences performance during a cognitive test.

Benchmarking in Academic Physical Therapy Using the PT-GQ Survey: Wave 2 Update With Application to Accreditation Reporting.

OBJECTIVE: The Benchmarking in Academic Physical Therapy study uses the Physical Therapist-Graduation Questionnaire (PT-GQ) survey to develop comprehensive performance benchmarks for physical therapist education. These benchmarks facilitate interprofessional comparisons and have application to accreditation self-study reporting. The purpose of this study is to report updated benchmarks from enrollment Wave 2 of the study, with an emphasis on curricular areas that align with accreditation standards. METHODS: Seventy doctor of physical therapy (DPT) programs (26.5% national sample) administered the survey to graduates during 2020-2021. Where possible, respondent data were contextualized by statistical comparison with published medical student data (Welch t test, Hedges g). RESULTS: There were 1894 respondents who participated in the study (response rate: 63.9%). The average survey duration was 32.9 minutes. White-only, non-Hispanic/Latino/a/x individuals (78.8%) exceeded the 2020 US Census prevalence (60.1%), and only one-half of respondents perceived a benefit to their training from the diversity present in their programs. Over 94% of respondents indicated that their curricula were characterized by "problem solving/critical thinking" and "clinical reasoning," but nearly one-half indicated "busywork" was prevalent. High curricular satisfaction ratings clustered in content areas relating to profession-specific technical skills and low ratings clustered in foundational sciences. DPT respondents reported significantly lower tolerance for ambiguity, significantly more exhaustion, and significantly less disengagement than medical students. Respondents endorsed higher levels of "adaptive" perfectionism (striving for high performance) than "maladaptive" perfectionism (concern over negative evaluations). Respondents with loans (27.7%) had debt exceeding $150,000, the benchmark above which the DPT degree loses economic power. CONCLUSION: PT-GQ benchmarks revealed strengths (eg, curricula emphasizing problem solving/critical thinking and clinical reasoning) and challenges (eg, low diversity, problematic student debt) in physical therapist education. IMPACT: Programs can use benchmarking for quality-improvement efforts and as a data source for accreditation self-study reports. The ongoing study will refine national benchmarks and pilot items to address new research questions.

Extracellular to Intracellular Body Water and Cognitive Function among Healthy Older and Younger Adults.

Compromised cognitive function is associated with increased mortality and increased healthcare costs. Physical characteristics including height, weight, body mass index, sex, and fat mass are often associated with cognitive function. Extracellular to intracellular body water ratio offers an additional anthropometric measurement that has received recent attention because of its association with systemic inflammation, hypertension, and blood−brain barrier permeability. The purposes of this study were to determine whether extracellular to intracellular body water ratios are different between younger and older people and whether they are associated with cognitive function, including executive function and attention, working memory, and information processing speed. A total of 118 healthy people (39 older; 79 younger) participated in this study. We discovered that extracellular to intracellular body water ratio increased with age, was predictive of an older person's ability to inhibit information and stay attentive to a desired task (Flanker test; R2 = 0.24; p < 0.001), and had strong sensitivity (83%) and specificity (91%) to detect a lower executive function score. These findings support that extracellular to intracellular body water ratio offers predictive capabilities of cognitive function, even in a healthy group of elderly people.

Corticospinal modulation of vibration-induced H-reflex depression.

The purpose of this study was to examine corticospinal modulation of spinal reflex excitability, by determining the effect of transcranial magnetic stimulation (TMS) on soleus H-reflexes while they were almost completely suppressed by lower extremity vibration. In 15 healthy adults, a novel method of single-limb vibration (0.6 g, 30 Hz, 0.33 mm displacement) was applied to the non-dominant leg. Soleus muscle responses were examined in six stimulation conditions: (1) H-reflex elicited by tibial nerve stimulation, (2) tibial nerve stimulation during vibration, (3) subthreshold TMS, (4) subthreshold TMS during vibration, (5) tibial nerve stimulation 10 ms after a subthreshold TMS pulse, and (6) tibial nerve stimulation 10 ms after a subthreshold TMS pulse, during vibration. With or without vibration, subthreshold TMS produced no motor evoked potentials and had no effect on soleus electromyography (p > 0.05). In the absence of vibration, H-reflex amplitudes were not affected by subthreshold TMS conditioning (median (md) 35, interquartile range (IQ) 18-56 vs. md 46, IQ 22-59% of the maximal M wave (Mmax), p > 0.05). During vibration, however, unconditioned H-reflexes were nearly abolished, and a TMS conditioning pulse increased the H-reflex more than fourfold (md 0.3, IQ 0.1-0.7 vs. md 2, IQ 0.9-5.0% of Mmax, p < 0.008). Limb vibration alone had no significant effect on corticospinal excitability. In the absence of vibration, a subthreshold TMS pulse did not influence the soleus H-reflex. During limb vibration, however, while the H-reflex was almost completely suppressed, a subthreshold TMS pulse partially restored the H-reflex. This disinhibition of the H-reflex by a corticospinal signal may represent a mechanism involved in the control of voluntary movement. Corticospinal signals that carry the descending motor command may also reduce presynaptic inhibition, temporarily increasing the impact of sensory inputs on motoneuron activation.

Cognitive function, quality of life, and aging: relationships in individuals with and without spinal cord injury.

Background: Correlations between aging, cognitive impairment and poor quality of life (QOL) have been observed for many patient populations.Objective: The purpose of this study was to examine these correlations in individuals with and without spinal cord injury (SCI).Methods: 23 individuals with complete SCI and 20 individuals without SCI ("NON") underwent assessment of cognitive function via the NIH Toolbox for Neurological and Behavioral Function. Participants self-rated QOL via global and symptom/domain-specific measures.Results: SCI rated global QOL to be lower than NON for the EQ-5D QALY (p < .001), but not the EQ-5D VAS, which imposes no penalty for wheeled mobility. Low QOL clustered mainly in domains pertaining to physical function/symptoms. Participants with SCI reported high QOL for positive affect/well-being and resilience. Cognitive function in SCI did not differ from NON. However, strong correlations between age and cognition observed in NON (all R2 > 0.532) were absent in SCI. Significant correlations between cognition and QOL were prevalent for NON but not for SCI.Conclusions: Dissociation of age, cognition and QOL occurred with SCI. Divergence between EQ-5D QALY and VAS suggests that individuals with SCI may recalibrate personal assessments of QOL in ways that minimize the importance of mobility impairment.

Genomic and Epigenomic Evaluation of Electrically Induced Exercise in People With Spinal Cord Injury: Application to Precision Rehabilitation.

OBJECTIVE: Physical therapists develop patient-centered exercise prescriptions to help overcome the physical, emotional, psychosocial, and environmental stressors that undermine a person's health. Optimally prescribing muscle activity for people with disability, such as a spinal cord injury, is challenging because of their loss of volitional movement control and the deterioration of their underlying skeletal systems. This report summarizes spinal cord injury-specific factors that should be considered in patient-centered, precision prescription of muscle activity for people with spinal cord injury. This report also presents a muscle genomic and epigenomic analysis to examine the regulation of the proliferator-activated receptor γ coactivator 1α (PGC-1α) (oxidative) and myostatin (hypertrophy) signaling pathways in skeletal muscle during low-frequency (lower-force) electrically induced exercise versus higher-frequency (higher-force) electrically induced exercise under constant muscle recruitment (intensity). METHODS: Seventeen people with spinal cord injury participated in 1 or more unilateral electrically induced exercise sessions using a lower-force (1-, 3-, or 5-Hz) or higher-force (20-Hz) protocol. Three hours after the exercise session, percutaneous muscle biopsies were performed on exercised and nonexercised muscles for genomic and epigenomic analysis. RESULTS: We found that low-frequency (low-force) electrically induced exercise significantly increased the expression of PGC-1α and decreased the expression of myostatin, consistent with the expression changes observed with high-frequency (higher-force) electrically induced exercise. Further, we found that low-frequency (lower-force) electrically induced exercise significantly demethylated, or epigenetically promoted, the PGC-1α signaling pathway. A global epigenetic analysis showed that >70 pathways were regulated with low-frequency (lower-force) electrically induced exercise. CONCLUSION: These novel results support the notion that low-frequency (low-force) electrically induced exercise may offer a more precise rehabilitation strategy for people with chronic paralysis and severe osteoporosis. Future clinical trials are warranted to explore whether low-frequency (lower-force) electrically induced exercise training affects the overall health of people with chronic spinal cord injury.

Epigenetics and the International Classification of Functioning, Disability and Health Model: Bridging Nature, Nurture, and Patient-Centered Population Health.

Epigenetic processes enable environmental inputs such as diet, exercise, and health behaviors to reversibly tag DNA with chemical "marks" that increase or decrease the expression of an individual's genetic template. Over time, epigenetic adaptations enable the effects of healthy or unhealthy stresses to become stably expressed in the tissue of an organism, with important consequences for health and disease. New research indicates that seemingly non-biological factors such as social stress, poverty, and childhood hardship initiate epigenetic adaptations in gene pathways that govern inflammation and immunity, two of the greatest contributors to chronic diseases such as diabetes and obesity. Epigenetic processes therefore provide a biological bridge between the genome-an individual's genetic inheritance-and the Social Determinants of Health-the conditions in which they are born, grow, live, work, and age. This Perspective paper argues that physical therapy clinicians, researchers, and educators can use the theoretical framework provided by the International Classification of Functioning, Disability, and Health (ICF model) to harmonize new discoveries from both public health research and medically focused genomic research. The ICF model likewise captures the essential role played by physical activity and exercise, which initiate powerful and widespread epigenetic adaptations that promote health and functioning. In this proposed framework, epigenetic processes transduce the effects of the social determinants of health and behaviors such as exercise into stable biological adaptations that affect an individual's daily activities and their participation in social roles. By harmonizing "nature" and "nurture," physical therapists can approach patient care with a more integrated perspective, capitalizing on novel discoveries in precision medicine, rehabilitation science, and in population-level research. As the experts in physical activity and exercise, physical therapists are ideally positioned to drive progress in the new era of patient-centered population health care.