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.

Myotonic dystrophy type 1 alters muscle twitch properties, spinal reflexes, and perturbation-induced trans-cortical reflexes.

BACKGROUND: Neurophysiologic biomarkers are needed for clinical trials of therapies for myotonic dystrophy (DM1). We characterized muscle properties, spinal reflexes (H-reflexes), and trans-cortical long-latency reflexes (LLRs) in a cohort with mild/moderate DM1. METHODS: Twenty-four people with DM1 and 25 matched controls underwent assessment of tibial nerve H-reflexes and soleus muscle twitch properties. Quadriceps LLRs were elicited by delivering an unexpected perturbation during a single-limb squat (SLS) visuomotor tracking task. RESULTS: DM1 was associated with decreased H-reflex depression. The efficacy of doublet stimulation was enhanced, yielding an elevated double-single twitch ratio. DM1 participants demonstrated greater error during the SLS task. DM1 individuals with the least-robust LLR responses showed the greatest loss of spinal H-reflex depression. CONCLUSIONS: DM1 is associated with abnormalities of muscle twitch properties. Co-occurring alterations of spinal and trans-cortical reflex properties underscore the central nervous system manifestations of this disorder and may assist in gauging efficacy during clinical trials.

Sustained submaximal contraction yields biphasic modulation of soleus Post-activation depression in healthy humans.

The amplitude of the H-reflex during the development and progression of fatigue reflects a complex interplay between central and peripheral factors. The purpose of this study is to characterize H-reflex homosynaptic post-activation depression (PAD) in an online fashion during a sustained submaximal fatigue task. The task required a high motor output in order to increase the likelihood of creating partial muscle ischemia with accumulation of fatigue metabolites, an important potential inhibitory influence upon the H-reflex during the progression of fatigue. Eleven subjects without neurologic impairment maintained volitional, isometric plantar flexion at 60% of maximal voluntary contraction until exhaustion. A paired-pulse stimulus (2 Hz) was delivered to the tibial nerve to elicit paired H-reflexes before, during, and after the fatigue protocol. The normalized amplitude of the second H-reflex (depression ratio) served as an estimate of PAD. Depression ratio increased during the first half of the fatigue protocol (P < 0.001), indicating a diminution of PAD, and then returned as exhaustion approached. The biphasic behavior of homosynaptic H-reflex depression during fatigue to exhaustion suggests a role for metabolic mediators of post-activation depression during fatigue.

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.

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.

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.

Active-resisted stance modulates regional bone mineral density in humans with spinal cord injury.

OBJECTIVE: In people with spinal cord injury (SCI), active-resisted stance using electrical stimulation of the quadriceps delivered a therapeutic stress to the femur (∼150% of body weight) and attenuated bone mineral density (BMD) decline. In standard densitometry protocols, BMD is averaged over the entire bone cross-section. An asymmetric adaptation to mechanical load may be masked by non-responding regions. The purpose of this study was to test a novel method to assess regional BMD of the femur in individuals with SCI. We hypothesize that there will be regional bone-sparing changes as a result of active-resisted stance. DESIGN: Mixed cross-sectional and longitudinal. SETTING: Research laboratory. PARTICIPANTS: Twelve individuals with SCI and twelve non-SCI controls. INTERVENTION: Individuals with SCI experienced active-resisted stance or passive stance for up to 3 years. OUTCOME MEASURES: Peripheral quantitative computed tomography images from were partitioned so that femur anatomic quadrants could be separately analyzed. RESULTS: Over 1.5 years, the slope of BMD decline over time was slower at all quadrants for the active-resisted stance limbs. At >2 years of training, BMD was significantly higher for the active-resisted stance group than for the passive stance group (P = 0.007). BMD was preferentially spared in the posterior quadrants of the femur with active-resisted stance. CONCLUSIONS: A regional measurement technique revealed asymmetric femur BMD changes between passive stance and active-resisted stance. Future studies are now underway to better understand other regional changes in BMD after SCI.

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.

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.

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.

Altered mRNA expression after long-term soleus electrical stimulation training in humans with paralysis.

In humans, spinal cord injury (SCI) induces deleterious changes in skeletal muscle that may be prevented or reversed by electrical stimulation muscle training. The molecular mechanisms underlying muscle stimulation training remain unknown. We studied two unique SCI subjects whose right soleus received >6 years of training (30 minutes/day, 5 days/week). Training preserved torque, fatigue index, contractile speed, and cross-sectional area in the trained leg, but not the untrained leg. Training decreased 10 mRNAs required for fast-twitch contractions and mRNA that encodes for myostatin, an autocrine/paracrine hormone that inhibits muscle growth. Conversely, training increased 69 mRNAs that mediate the slow-twitch, oxidative phenotype, including PGC-1α, a transcriptional coactivator that inhibits muscle atrophy. When we discontinued right soleus training, training-induced effects diminished slowly, with some persisting for >6 months. Training of paralyzed muscle induces localized and long-lasting changes in skeletal muscle mRNA expression that improve muscle mass and function.

Enhancing muscle force and femur compressive loads via feedback-controlled stimulation of paralyzed quadriceps in humans.

OBJECTIVE: To compare paralyzed quadriceps force properties and femur compressive loads in an upright functional task during conventional constant-frequency stimulation and force feedback-modulated stimulation. DESIGN: Crossover trial. SETTING: Research laboratory. PARTICIPANTS: Subjects (N=13; 12 men, 1 woman) with motor-complete spinal cord injury. INTERVENTIONS: Subjects performed 2 bouts of 60 isometric quadriceps contractions while supported in a standing frame. On separate days, subjects received constant-frequency stimulation at 20Hz (CONST) or frequency-modulated stimulation triggered by a change in force (FDBCK). During FDBCK, a computer algorithm responded to each 10% reduction in force with a 20% increase in stimulation frequency. MAIN OUTCOME MEASURES: A biomechanical model was used to derive compressive loads on the femur, with a target starting dose of load equal to 1.5 times body weight. RESULTS: Peak quadriceps force and fatigue index were higher for FDBCK than CONST (P<.05). Within-train force decline was greater during FDBCK bouts, but mean force remained above CONST values (P<.05). As fatigue developed during repetitive stimulation, FDBCK was superior to CONST for maintenance of femur compressive loads (P<.05). CONCLUSIONS: Feedback-modulated stimulation in electrically activated stance is a viable method to maximize the physiologic performance of paralyzed quadriceps muscle. Compared with CONST, FDBCK yielded compressive loads that were closer to a targeted dose of stress with known osteogenic potential. Optimization of muscle force with FDBCK may be a useful tactic for future training-based antiosteoporosis protocols.

Motor demands of cognitive testing may artificially reduce executive function scores in individuals with spinal cord injury.

Objective: To determine whether the motor demands of cognitive tests contribute to differences in cognitive function scores in participants with and without spinal cord injury (SCI).Design: Cohort study.Setting: Rehabilitation research laboratory.Participants: 68 individuals without SCI ("NON") and 22 individuals with motor complete SCI ("SCI").Interventions: None.Outcome Measures: NIH Toolbox cognitive assessments, including two with motor demands and reaction-time based scoring (Dimensional Change Card Sort (DCCS), Flanker Inhibitory Control and Attention (Flanker) and two without timed scoring (List Sorting Working Memory (List Sorting), Picture Sequence Memory Test (Picture Sequence). Tests were administered with and without the assistance of a proctor on two randomly-determined days (>24 hr interval). For DCCS and Flanker, the motor-task score offset was estimated as the difference between the proctored and non-proctored scores.Results: For demographically-corrected data, proctoring reduced DCCS and Flanker scores (P < 0.001) but mitigated apparent differences between SCI and NON (all P > 0.403). SCI and NON did not differ for List Sorting (P > 0.072) but did differ significantly for Picture Sequence (P < 0.001). Significant practice effects existed for memory-based tests (List Sorting and Picture Sequence); all P < 0.015, effect size>0.645.Conclusions: DCCS and Flanker scores for individuals with SCI may be artificially reduced consequent to secondary motor demands of the tests. Proctoring and computation of a motor-response score offset enables comparisons to be made between individuals with SCI and a Non-SCI control cohort; however, further work is needed to determine whether offset-adjusted scores can be compared to standardized normative values.

Benchmarking in Academic Physical Therapy: A Multicenter Trial Using the PT-GQ Survey.

OBJECTIVE: Academic physical therapy has no universal metrics by which educational programs can measure outcomes, limiting their ability to benchmark to their own historical performance, to peer institutions, or to other health care professions. The PT-Graduation Questionnaire (GQ) survey, adapted from the Association of American Medical Colleges' GQ, addresses this gap by offering both inter-professional insight and fine-scale assessment of physical therapist education. This study reports the first wave of findings from an ongoing multi-site trial of the PT-GQ among diverse academic physical therapy programs, including (1) benchmarks for academic physical therapy, and (2) a comparison of the physical therapist student experience to medical education benchmarks. METHODS: Thirty-four doctor of physical therapy (DPT) programs (13.2% nationwide sample) administered the online survey to DPT graduates during the 2019 to 2020 academic year. PT-GQ and Association of American Medical Colleges data were contrasted via Welch's unequal-variance t test and Hedges g (effect size). RESULTS: A total of 1025 respondents participated in the study (response rate: 63.9%). The average survey duration was 31.8 minutes. Overall educational satisfaction was comparable with medicine, and respondents identified areas of curricular strength (eg, anatomy) and weakness (eg, pharmacology). DPT respondents provided higher ratings of faculty professionalism than medicine, lower rates of student mistreatment, and a lesser impact of within-program diversity on their training. One-third of respondents were less than "satisfied" with student mental health services. DPT respondents reported significantly higher exhaustion but lower disengagement than medical students, along with lower tolerance for ambiguity. Of DPT respondents who reported educational debt, one-third reported debt exceeding $150,000, the threshold above which the DPT degree loses economic power. CONCLUSIONS: These academic benchmarks, using the PT-GQ, provided insight into physical therapist education and identified differences between physical therapist and medical student perceptions. IMPACT: This ongoing trial will establish a comprehensive set of benchmarks to better understand academic physical therapy outcomes.

NIH Toolbox Cognition Battery in Young and Older Adults: Reliability and Relationship to Adiposity and Physical Activity.

BACKGROUND AND PURPOSE: Executive function in normal aging may be modulated by body habitus and adiposity, both factors modified by physical therapist prescriptions. This study measured between-day reliability of executive function metrics in young and older individuals and examined associations between cognition, adiposity, and physical activity. METHODS: Forty-three young and 24 older participants underwent executive function assessment via the National Institutes of Health Toolbox Cognition Battery (Dimensional Change Card Sort, Flanker Inhibitory Control and Attention [Flanker], and List Sorting Working Memory [List Sorting]) at 7-day intervals. Between-day reliability was assessed via intraclass correlation (ICC). Responsiveness was assessed via between-day effect size and Cohen's d. Forward stepwise linear regression examined associations between cognition and age, body mass index, percent body fat, and a self-report measure of physical activity (International Physical Activity Questionnaire Short Form). RESULTS AND DISCUSSION: Executive function scores were higher for young participants than for older participants (all P < .002), consistent with typical age-related cognitive decline. Reliability of cognitive metrics was higher for older participants (ICC = 0.483-0.917) than for young participants (ICC = 0.386-0.730). Between-day effect sizes were approximately 50% smaller for older participants. Percent body fat significantly correlated with the Flanker Unadjusted Scale (P = .004, R2 = 0.0772). Neither vigorous nor total physical activity correlated with any cognitive metric. CONCLUSIONS: Older participants demonstrated greater between-day reliability for executive function measures, while young participants showed greater capacity to improve performance upon repeat exposure to a cognitive test (especially Flanker). Percent body fat correlated significantly with Flanker scores, while body mass index (an indirect measure of body fat) did not. Self-reported physical activity did not correlate with executive function. Cognitive response to physical therapist-prescribed exercise is a fertile ground for future research.

Hybrid stimulation enhances torque as a function of muscle fusion in human paralyzed and non-paralyzed skeletal muscle.

OBJECTIVE: After spinal cord injury (SCI), hybrid stimulation patterns that interpose paired-pulse doublets over a constant-frequency background may enhance the metabolic "work" (muscle torque) performed by paralyzed muscle. This study examined the effect of background stimulation frequency on the torque contribution of the doublet before and after fatigue. DESIGN: Cross-sectional study. SETTING: Research laboratory in an academic medical center. PARTICIPANTS: Five men with chronic sensory and motor-complete SCI and ten non-SCI controls (6 males, 4 females). SCI subjects were recruited from a long-term study of unilateral plantar-flexor training; both limbs were tested for the present study. INTERVENTIONS: Subjects underwent plantar flexor stimulation at 5, 7, 9, and 12 Hz. The four background frequencies were overlaid with 6 ms doublets delivered at the start, middle, or at both the start and middle of each train. The 5 Hz and 12 Hz frequencies were analyzed after fatigue. OUTCOME MEASURES: Mean torque, peak torque, torque fusion index, doublet torque. RESULTS: Trains with doublets at both the start and middle yielded the most consistent enhancement of torque (all P < 0.028). Torque contribution of the doublet was greatest at low stimulus frequencies (all P < 0.016). The low relative fusion of untrained paralyzed muscle preserved the efficacy of the doublet even during fatigue. CONCLUSION: Hybrid stimulus trains may be an effective way to increase contractile work in paralyzed muscle, even after fatigue. They may be useful for rehabilitation strategies designed to enhance the metabolic work performed by paralyzed skeletal muscle.

Doublet stimulation protocol to minimize musculoskeletal stress during paralyzed quadriceps muscle testing.

With long-term electrical stimulation training, paralyzed muscle can serve as an effective load delivery agent for the skeletal system. Muscle adaptations to training, however, will almost certainly outstrip bone adaptations, exposing participants in training protocols to an elevated risk for fracture. Assessing the physiological properties of the chronically paralyzed quadriceps may transmit unacceptably high shear forces to the osteoporotic distal femur. We devised a two-pulse doublet strategy to measure quadriceps physiological properties while minimizing the peak muscle force. The purposes of the study were 1) to determine the repeatability of the doublet stimulation protocol, and 2) to compare this protocol among individuals with and without spinal cord injury (SCI). Eight individuals with SCI and four individuals without SCI underwent testing. The doublet force-frequency relationship shifted to the left after SCI, likely reflecting enhancements in the twitch-to-tetanus ratio known to exist in paralyzed muscle. Posttetanic potentiation occurred to a greater degree in subjects with SCI (20%) than in non-SCI subjects (7%). Potentiation of contractile rate occurred in both subject groups (14% and 23% for SCI and non-SCI, respectively). Normalized contractile speed (rate of force rise, rate of force fall) reflected well-known adaptations of paralyzed muscle toward a fast fatigable muscle. The doublet stimulation strategy provided repeatable and sensitive measurements of muscle force and speed properties that revealed meaningful differences between subjects with and without SCI. Doublet stimulation may offer a unique way to test muscle physiological parameters of the quadriceps in subjects with uncertain musculoskeletal integrity.

Dose estimation and surveillance of mechanical loading interventions for bone loss after spinal cord injury.

BACKGROUND AND PURPOSE: The interpretation of the results of previous anti-osteoporosis interventions after spinal cord injury (SCI) is undermined by incomplete information about the intervention dose or patient adherence to dose requirements. Rehabilitation research as a whole traditionally has struggled with these same issues. The purpose of this case report is to offer proof of the concepts that careful dose selection and surveillance of patient adherence should be integral components in rehabilitation interventions. CASE DESCRIPTION: A 21-year-old man with T4 complete paraplegia (7 weeks) enrolled in a unilateral soleus muscle electrical stimulation protocol. Compressive loads applied to the tibia approximated 1.4 times body weight. Over 4.8 years of home-based training, data logging software provided surveillance of adherence. Soleus muscle torque and fatigue index adaptations to training as well as bone mineral density (BMD) adaptations in the distal tibia were measured. OUTCOMES: The patient performed nearly 8,000 soleus muscle contractions per month, with occasional fluctuations. Adherence tracking permitted intervention when adherence fell below acceptable values. The soleus muscle torque and fatigue index increased rapidly in response to training. The BMD of the untrained tibia declined approximately 14% per year. The BMD of the trained tibia declined only approximately 7% per year. The BMD was preferentially preserved in the posterior half of the tibia; this region experienced only a 2.6% annual decline. DISCUSSION: Early administration of a load intervention, careful estimation of the loading dose, and detailed surveillance of patient adherence aided in the interpretation of a patient's adaptations to a mechanical load protocol. These concepts possess wider applicability to rehabilitation research and should be emphasized in future physical therapy investigations.

Physiotherapy education is a good financial investment, up to a certain level of student debt: an inter-professional economic analysis.

QUESTIONS: What is the economic value of a physiotherapy career relative to other healthcare professions? Is the graduate debt reported for physiotherapy manageable according to recommended salary-weighted debt service ratio benchmarks? DESIGN: Net present value (NPV) is an economic modelling approach that compares costs and benefits of an investment such as healthcare education. An economic analysis using the NPV approach was conducted and reported in US dollars for the Doctor of Physical Therapy degree. Comparable calculations were made for a range of other healthcare qualifications. Debt service ratios were also calculated under a range of scenarios. OUTCOME MEASURES: Entry-level salaries and rate of salary growth were obtained from government databases. Student debt levels were obtained from published sources. Because no national estimate exists for physical therapy student debt, debt was modelled for recent Doctor of Physical Therapy (DPT) graduates and for several hypothetical debt tiers. The NPV modelled future physical therapy earnings less the cost of education and the opportunity cost of foregone earnings from alternate careers. RESULTS: At the debt level reported by recent graduates (US $86563), physical therapy NPV was higher than occupational therapy, optometry, veterinary medicine, and chiropractic but lower than dentistry, pharmacy, nurse practitioner, physician assistant, and all medical specialties. At $150000 debt, physical therapy NPV falls below all careers except veterinary medicine and chiropractic. Students with>$200000 debt may not achieve recommended repayment benchmarks. At high debt levels (>$266000), physical therapy NPV no longer exceeds that of a bachelor's degree. CONCLUSION: Physiotherapy education is a good financial investment, up to a certain level of student debt. Students should carefully consider the amount of debt they are willing to incur in order to pursue a physiotherapy career. Likewise, physiotherapy education programs should consider the role they may play in bolstering the economic value of their graduates' future careers. [Shields RK, Dudley-Javoroski S (2018) Physiotherapy education is a good financial investment, up to a certain level of student debt: an inter-professional economic analysis. Journal of Physiotherapy 64: 182-190].

Precision Physical Therapy: Exercise, the Epigenome, and the Heritability of Environmentally Modified Traits.

One of the newest frontiers of physical therapy is the field of epigenetics, which examines how pervasive environmental factors such as exercise regulate the expression of genes. The epigenome may be one of the most powerful systems through which exercise exerts its beneficial effects on health and longevity. Large epidemiology studies show that individuals who regularly exercise demonstrate a lower "epigenetic age," experience fewer metabolic diseases, and enjoy greater longevity. However, the dose, mode, intensity, and duration of exercise required to achieve a healthy epigenetic profile is unknown. As experts in exercise prescription, physical therapists are ideally suited to contribute to the discovery of this dose-response relationship. This perspective makes a case for the genesis of "precision physical therapy," which capitalizes on epigenetic discoveries to optimize exercise-based interventions. Summarized here is the emerging body of knowledge supporting epigenetic adaptations to exercise in humans, including the intriguing possibility that these environmentally modified traits could be passed down to offspring. In the future, it is likely that epigenetic data will enhance our understanding of individual disease risk and individual response to prescribed exercise. The profession of physical therapy must be alert to new epigenetic knowledge that can enhance the specificity and efficacy of movement-based treatments.