Global Cognition, Gender, and Level of Education Predict Dual-Task Gait Speed Variability Metrics in Older Adults.

INTRODUCTION: The purpose of this study was to determine if demographic variables and measures of cognitive function, functional mobility, self-reported balance self-efficacy, and self-reported physical activity can predict gait speed variability during single-task walking (STGSCV), during cognitive-motor dual-tasking (DTGSCV), and dual-task effect on gait speed variability (DTEGSCV) in older adults. METHODS: In 62 older adults, demographics were recorded and cognitive function (including the Montreal Cognitive Assessment, MoCA), functional mobility, balance self-efficacy (Activities-specific Balance Confidence Scale, ABC), and self-reported physical activity (Physical Activity Scale for the Elderly, PASE) were assessed. Three linear regression models were used to determine whether the functional mobility tests, PASE score, ABC score, and tests of cognitive function predicted gait speed variability outcomes (STGSCV, DTGSCV, DTEGSCV), with demographics included as covariates. RESULTS: MoCA score (p = 0.003), gender (p = 0.040), and years of education (p = 0.010) significantly predicted DTGSCV (R2 = 0.297, p = 0.002). MoCA score (p = 0.008) and years of education (p < 0.001) also significantly predicted DTEGSCV. Despite a significant regression model (R2 = 0.316, p = 0.001), there were no significant individual predictors of STGSCV. CONCLUSION: Older adults with lower cognitive function scores, according to the MoCA, and higher levels of education demonstrate larger gait speed variability during dual-tasking and may be at increased risk of real-world mobility issues or falling.

Offloading of Diabetic Neuropathic Plantar Ulcers: Secondary Analysis of Step Activity and Ulcer Healing.

OBJECTIVE: Although it is well-known that offloading devices facilitate healing in people with diabetes and neuropathic plantar ulcers, little is known about how step activity affects healing. The purposes of this study were to compare: (1) healing outcomes (time to healing, percentage of ulcers healed); (2) healing rates by ulcer location; and (3) step activity (daily step count, daily peak mean cadence) among patients using either total contact casts (TCCs) or removable cast walker boots (RCWs). METHODS: The study included 55 participants (TCC, 29; RCW, 26) with diabetes mellitus, peripheral neuropathy, and a Wagner grade 1 or 2 neuropathic plantar ulcer. Each participant wore an activity monitor for 14 consecutive days. Step activity and healing variables were assessed using independent t tests, Kruskal-Wallis, Kaplan-Meier, and Mantel-Cox log-rank tests. RESULTS: Mean participant age was 55 (SD, 11) years. The percentage of ulcers healed was lower in the RCW group versus the TCC group (65% vs 93%). If healed, average healing rate was 77 (SD, 48) days in the TCC group and 138 (SD, 143) days in the RCW group. Survival distribution by ulcer location was different for RCW forefoot than other locations (132 ± 13 days vs 91 ± 15, 75 ± 11, and 102 ± 36 days for TCC forefoot, TCC-midfoot/hindfoot, and RCW-midfoot/hindfoot, respectively; χ2 = 10.69, P = .014). Average step count was 2,597 in the RCW group versus 1,813 steps in the TCC group (P = .07). The daily peak mean cadence for 20-, 30-, or 60-minute periods was greater with RCW use. CONCLUSIONS: Step activity in participants with RCWs was increased compared with those with TCCs. Because of their potential to be easily removable, RCWs may impair ulcer healing by allowing greater step activity.

Correlations of Single-Leg Performance Tests to Patient-Reported Outcomes After Primary Anterior Cruciate Ligament Reconstruction.

OBJECTIVE: To determine the relationship between patient-reported outcomes (PROs) to the single-leg step-down test (SLSD) and the Y-balance anterior reach (YB-A) 6 months after primary anterior cruciate ligament reconstruction (ACLR). DESIGN: Cross-sectional. SETTING: Laboratory. PARTICIPANTS: Sixty-six patients 6 months after ACLR participated. INTERVENTIONS: Patients performed the SLSD, YB-A, and completed PROs after ACLR. MAIN OUTCOME MEASURES: Patients completed the International Knee Documentation Committee Score (IKDC), the Lysholm Activity Scale, the Tampa Scale of Kinesiophobia (TSK-11), and the Knee Injury and Osteoarthritis Outcome Score (KOOS)-Symptom, -Sport, and -Quality of Life (QOL) subscales. The SLSD requires subjects to complete as many single-leg step-downs as possible in 60 seconds, and the YB-A involves reaching anteriorly on a single limb. Pearson product moment correlations were used to assess relationships between the YB-A and SLSD performance to each PRO. RESULTS: Single-leg step-down test symmetry was significantly correlated with the TSK-11 (r = -0.70), KOOS-Sport (r = 0.40), -Symptom (r = 0.46), and -QOL (r = 0.42). The YB-A symmetry was significantly correlated with the KOOS-Symptom (r = 0.30) and KOOS-Sport (r = 0.30). CONCLUSIONS: Single-leg step-down test performance demonstrated stronger relationships to patient-reported knee function than the YB-A. Furthermore, the SLSD symmetry was strongly correlated with fear of movement. The SLSD provides a robust method for clinicians to assess dynamic knee function and may aid in identifying patients who could benefit from intervention to reduce fear of movement or reinjury.

Step descent strategy is altered bilaterally despite unilateral muscle strength impairment after total knee arthroplasty.

PURPOSE: Muscle weakness and difficulty descending stairs are common after unilateral total knee arthroplasty (TKA), but the relationship between each is unclear. The purpose of this study was to compare lower extremity muscle strength, lower extremity support moments during step descent, and assess relationships between each. METHODS: The study included 40 subjects (20 post-TKA, 20 control). Knee extensor, hip abductor, and hip external rotator strength were measured and biomechanical analyses of step descent performed. Patients with TKA were assessed 3 and 6 months post-surgery. RESULTS: At 3 and 6 months post-TKA, operated limb hip external rotator and knee extensor strength were impaired compared to the non-operated limb (p < 0.01); however, no between-limb differences were observed during step descent. Compared to the control group, hip external rotator and knee extensor strength, total lower extremity support moment, and knee support moment during step descent were impaired post-TKA (p < 0.05). At 6 months post-TKA, knee extensor and hip external rotator strength correlated with total support moment during step descent (rs = 0.40, 0.41, p < 0.02). Hip abductor and external rotator strength negatively correlated with knee support moment during step descent (rs = - 0.35, - 0.39, p < 0.03). CONCLUSIONS: Persistent operative limb knee extensor and hip external rotator muscle weakness are noted following unilateral TKA. Despite unilateral weakness, bilateral alterations in step descent strategy occur following TKA. Patients with TKA utilize hip musculature to reduce knee muscle demand during step descent, possibly contributing to limitations in long-term step descent performance.

Purification of a non-specific nucleoside hydrolase from Alaska pea seeds.

A non-specific nucleoside hydrolase has been isolated from germinated Alaska pea seeds. The enzyme catalyzes the hydrolysis of both purines and pyrimidines along with ribo- and deoxyribonucleosides. A purification scheme utilized ammonium sulfate precipitation, ion exchange chromatography and size exclusion chromatography, resulted in 103-fold purification with a recovery of 2.8%. The purified protein has a specific activity of 0.308 µmol/min•mg. The subunit molecular weight was 26103 Da and the enzyme exists as a dimer. The enzyme retains a significant amount of activity over a wide pH range with the maximum activity occurring at a pH of 6.0. The maximum activity was observed with adenosine as the substrate followed by inosine and guanosine, respectively. The Km for adenosine was 184 ±â€¯34 µM and for inosine 283 ±â€¯88 µM. In addition to the nucleoside hydrolase activity, adenosine deaminase activity was seen in the initial extract. Using adenosine as the substrate with the initial extract from the germinated seeds, the products adenine, inosine, and hypoxanthine were identified based on their retention times during reverse phase HPLC.

The classification of Cannabis hemp cultivars by thermal desorption direct analysis in real time mass spectrometry (TD-DART-MS) with chemometrics.

Cannabis has been cultivated as a source of food, fiber, and medicine globally, so the classification of Cannabis cultivars based on their chemical fingerprints is important to standardize and control the quality of Cannabis, ensure that patients receive a full and consistent spectrum of therapeutic benefits, and promote the further implementation of Cannabis-based products in clinical uses. In this study, a high-throughput analytical method, thermal desorption direct analysis in real time mass spectrometry (TD-DART-MS), was employed to classify various Cannabis hemp cultivars with multivariate analysis. Cannabis plant materials from four cultivars were analyzed directly by TD-DART-MS without solvent extraction. The total run time was 15 min including 8 min for data acquisition and 7 min for cooling down the thermal stage. Data preprocessing strategy such as data transformation was evaluated on the TD-DART-MS data set and cubic root transform has shown significant improvement to the classification. TD-DART-MS data was then processed by principal component analysis (PCA) and the results were compared with those from liquid chromatography-mass spectrometry (LC-MS) data. The samples were clustered based on cultivars by PCA, and the validation samples collected 2 months later were also grouped together with the original samples by cultivars after mean-centering the data sets. Partial least squares discriminant analysis (PLS-DA) models were constructed with the TD-DART-MS data sets and a 99.3 ± 0.3% classification accuracy was obtained from 100 independent bootstrapped Latin partition evaluations. Our results indicate that TD-DART-MS may be used as a screening tool for the classification of Cannabis cultivars. Graphical abstract.

Hip external rotation strength predicts hop performance after anterior cruciate ligament reconstruction.

PURPOSE: Quadriceps strength and single-leg hop performance are commonly evaluated prior to return to sport after anterior cruciate ligament reconstruction (ACLR). However, few studies have documented potential hip strength deficits after ACLR, or ascertained the relative contribution of quadriceps and hip strength to hop performance. METHODS: Patients cleared for return to sports drills after ACLR were compared to a control group. Participants' peak isometric knee extension, hip abduction, hip extension, and hip external rotation (HER) strength were measured. Participants also performed single-leg hops, timed hops, triple hops, and crossover hops. Between-limb comparisons for the ACLR to control limb and the non-operative limb were made using independent two-sample and paired sample t tests. Pearson's correlations and stepwise multiple linear regression were used to determine the relationships and predictive ability of limb strength, graft type, sex, and limb dominance to hop performance. RESULTS: Sixty-five subjects, 20 ACLR [11F, age 22.8 (15-45) years, 8.3 ± 2 months post-op, mass 70.47 ± 12.95 kg, height 1.71 ± 0.08 m, Tegner 5.5 (3-9)] and 45 controls [22F, age 25.8 (15-45) years, mass 74.0 ± 15.2 kg, height 1.74 ± 0.1 m, Tegner 6 (3-7)], were tested. Knee extension (4.4 ± 1.5 vs 5.4 ± 1.8 N/kg, p = 0.02), HER (1.4 ± 0.4 vs 1.7 ± 0.5 N/kg, p = 0.04), single-leg hop (146 ± 37 vs 182 ± 38% limb length, p < 0.01), triple hop (417 ± 106 vs 519 ± 102% limb length, p < 0.01), timed hop (3.3 ± 2.0 vs 2.3 ± 0.6 s, p < 0.01), and crossover hop (364 ± 107 vs 446 ± 123% limb length, p = 0.01) were significantly impaired in the operative versus control subject limbs. Similar deficits existed between the operative and non-operative limbs. Knee extension and HER strength were significantly correlated with each of the hop tests, but only HER significantly predicted hop performance. CONCLUSIONS: After ACLR, patients have persistent HER strength, knee extension strength, and hop test deficits in the operative limb compared to the control and non-operative limbs, even after starting sport-specific drills. Importantly, HER strength independently predicted hop performance. Based on these findings, to resolve between-limb deficits in strength and hop performance clinicians should include HER strengthening exercises in post-operative rehabilitation. LEVEL OF EVIDENCE: Prognostic Study, Level II.

Stability of pentobarbital in soil.

Intravenous injection of barbiturates, particularly pentobarbital (5-ethyl-5-pentan-2-yl-1,3-diazinane-2,4,5-trione), is a widely used method to euthanize large animals such as horses. However, one concern with this method is the fate of pentobarbital after the disposal of the carcass. As tissues decompose, pentobarbital may leach into the soil and from there migrate to groundwater. A method using methanol extraction, solid phase concentration, and liquid chromatography (LC/MS) has been developed to measure pentobarbital in soils. Recovery of pentobarbital from soil averaged approximately 85% from different soil types including topsoil, potting soil, sand, stall sweepings, and loam. The method was capable of detecting pentobarbital levels of 0.1 ppm. A calibration curve was constructed with a linear range of 1 ppm to 100 ppm. The limit of quantification was 0.5 ppm. The rate of degradation of pentobarbital in sand, topsoil, and potting soil was measured over a 17-week period. At the end of week 17, approximately 17% of the pentobarbital remained in the sand, 19% remained in the topsoil, and 10% remained in the potting soil. While there was a significant decrease in the pentobarbital recovered from the soil, there were still detectable amounts of pentobarbital present in the soil after 17 weeks. To determine the importance of bacterial degradation, the three soil types were autoclaved before addition of pentobarbital. After autoclaving, no degradation of pentobarbital was observed in sand and one topsoil sample, while there was no difference in the degradation of pentobarbital in autoclaved potting soil versus potting soil that had not undergone autoclaving.

Characterization of inosine-uridine nucleoside hydrolase (RihC) from Escherichia coli.

A non-specific nucleoside hydrolase from Escherichia coli (RihC) has been cloned, overexpressed, and purified to greater than 95% homogeneity. Size exclusion chromatography and sodium dodecyl sulfate polyacrylamide gel electrophoresis show that the protein exists as a homodimer. The enzyme showed significant activity against the standard ribonucleosides with uridine, xanthosine, and inosine having the greatest activity. The Michaelis constants were relatively constant for uridine, cytidine, inosine, adenosine, xanthosine, and ribothymidine at approximately 480µM. No activity was exhibited against 2'-OH and 3'-OH deoxynucleosides. Nucleosides in which additional groups have been added to the exocyclic N6 amino group also exhibited no activity. Nucleosides lacking the 5'-OH group or with the 2'-OH group in the arabino configuration exhibited greatly reduced activity. Purine nucleosides and pyrimidine nucleosides in which the N7 or N3 nitrogens respectively were replaced with carbon also had no activity.

Major adverse foot events and functional mobility deficits associated with diabetic neuropathy and nephropathy.

Aim: The purpose is to determine the risk ratios (RR) for both major adverse foot events (MAFEs) and the presence of moderate and severe functional mobility deficits in participants with diabetic peripheral neuropathy across the stages of chronic kidney disease (CKD). Methods: We studied 284 participants with diabetes mellitus, peripheral neuropathy, and CKD. MAFEs including foot fracture, ulcerations, Charcot neuropathic arthropathy (CN), osteomyelitis, and minor foot amputations were collected from foot x-ray reports in the medical records of 152 participants; functional mobility deficits were assessed in 132 participants using the modified physical performance test (mPPT). Moderate mobility deficit was categorized as mPPT scores 22-29 and severe mobility deficit as < 22. Unadjusted and adjusted (age, body weight, race, HbA1c) RR were calculated across each stage of CKD, with stage 1 CKD used as the reference group. Results: The RR for neuropathic foot fracture, CN, and diabetic foot ulceration remained consistent across CKD stages. The RR of minor amputation is greater in CKD stages 4 and 5. The RR of moderate or severe mobility deficit is greater in CKD stages 3 and 5 and in CKD stages 3, 4, and 5, respectively. An inverse association was observed between MAFE prevalence and mPPT scores across CKD stages. Conclusion: Major adverse foot events and functional mobility deficits are prevalent in individuals with DPN and diabetic kidney disease. The risks for minor foot amputation and functional mobility deficits increase as early as stage 3 CKD and increase further in stages 4 and 5.

Optimizing Total Knee Arthroplasty Rehabilitation with Telehealth Physical Activity Behavior Change Intervention: A Randomized Clinical Trial.

OBJECTIVE: Conventional total knee arthroplasty (TKA) rehabilitation has little impact on sedentary lifestyles that have negative long-term health consequences. The purpose of this trial was to determine the effect of telehealth-based physical activity behavior change intervention on physical activity and functional outcomes following TKA. METHODS: This study was a 2-arm, parallel randomized controlled superiority trial at a regional Veterans Affairs medical center. The participants were 92 US military Veterans (mean age = 65.7 [SD =7.8] y) undergoing unilateral TKA. The Physical Activity Behavior Change (PABC) intervention included telehealth-based self-management training (ten 30-minute sessions) delivered over 12 weeks. The control intervention included telehealth-based health education sessions that matched PABC frequency and duration. Both groups participated in standardized conventional outpatient rehabilitation. Physical activity, measured as average daily step count, was the primary outcome. Secondary outcomes were Life-Space Assessment questionnaire, 30-Second Chair-Stand test, Timed Up-and-Go Test, Six-Minute Walk test, Western Ontario and McMaster Universities Osteoarthritis Index, and Veterans RAND 12-Item Health Survey. The Self Efficacy for Exercise scale and daily time spent in different postures (sitting/lying, standing, stepping) were exploratory variables. Outcomes were measured at baseline (before surgery), mid-intervention (8 weeks after surgery), after the intervention (14 weeks after surgery; primary endpoint), and follow-up (38 weeks after surgery). RESULTS: The PABC group had an estimated 931 (95% CI = 42-1819) more daily steps than the control group from baseline to 14 weeks, though a between-group effect was not sustained at 38 weeks. There were no group differences in secondary outcomes. Participants included only military veterans using Veteran's Health Administration services. The intervention targeted self-management and did not include peer support. CONCLUSIONS: The PABC intervention improved physical activity for Veterans recovering from unilateral TKA at 14 weeks after surgery, though the effect was not sustained at 38 weeks. Physical function improved with rehabilitation but was not different between groups, indicating that physical function was not a primary driver of physical activity behavior. IMPACT: Conventional TKA rehabilitation has a negligible effect on free-living physical activity, which is relevant to long-term health outcomes. This trial identified telehealth physical activity self-management as effective in addressing activity behaviors, separate from conventional rehabilitation strategies.

Real-world data capture of daily limb loading using force-sensing insoles: Feasibility and lessons learned.

Force-sensing insoles are wearable technology that offer an innovative way to measure loading outside of laboratory settings. Few studies, however, have utilized insoles to measure daily loading in real-world settings. This is an ancillary study of a randomized controlled trial examining the effect of weight loss alone, weight loss plus weighted vest, or weight loss plus resistance training on bone health in older adults. The purpose of this ancillary study was to determine the feasibility of using force-sensing insoles to collect daily limb loading metrics, including peak force, impulse, and loading rate. Forty-four participants completed a baseline visit of three, 2-minute walking trials while wearing force-sensing insoles. During month two of the intervention, 37 participants wore insoles for 4 days for 8 waking hours each day. At 6-month follow-up, participants completed three, two-minute walking trials and a satisfaction questionnaire. Criteria for success in feasibility was defined as: a) > 60 % recruitment rate; b) > 80 % adherence rate; c) > 75 % of usable data, and d) > 75 % participant satisfaction. A 77.3 % recruitment rate was achieved, with 44 participants enrolled. Participants wore their insoles an average of 7.4 hours per day, and insoles recorded an average of 5.5 hours per day. Peak force, impulse, and loading rate collected at baseline and follow-up were 100 % usable. During the real-world settings, 87.8 % of data was deemed usable with an average of 1200 min/participant. Lastly, average satisfaction was 80.5 %. These results suggest that force-sensing insoles appears to be feasible to capture real-world limb loading in older adults.

The effect of exercise, physical activity, stepping characteristics, and loading on diabetic foot ulcer healing: a systematic review.

The aim of this review was to investigate the effect of exercise, physical activity, stepping characteristics, and loading on DFU healing. A systematic review using proprietary software and a PRISMA 2020 checklist was performed by searching MEDLINE, ProQuest, Scopus, CINAHL, Ovid, and the Cochrane Library for eligible articles from 1960 to December 2020. The primary outcome was time to wound closure. Other outcomes included percentage of DFU healed and time to percentage reduction in DFU. Of the 9 articles included, 6 addressed step activity during the off-loading phase of healing and 3 investigated the addition of NWB exercise on wound healing. Reduced loading via lower daily step activity, less standing duration, and shorter walking bouts in combination with wearing an off-loading device facilitated more rapid wound healing. Exercise seemed to facilitate more rapid healing, as well. Reduced limb loading via daily activity and use of offloading devices improved DFU healing rates. Additional research is necessary to determine the optimal thresholds for exercise, activity, step characteristics, and loading to improve healing outcomes in persons with DFU.

Clinical utility of the Trendelenburg Test in people with multiple sclerosis.

BACKGROUND: The clinical utility of the Trendelenburg Test remains unknown in people with multiple sclerosis (MS). OBJECTIVE: To measure (1) intra-rater reliability, (2) agreement of goniometer-assessed Trendelenburg pelvis-on-femur angle (POF) with motion capture, and (3) concurrent validity of Trendelenburg POF and hip abduction strength with POF during walking and step negotiation. METHODS: Trendelenburg POF was measured in 20 people with MS using goniometry and motion analysis. In addition, peak POF was measured using motion analysis during walking, step ascent, and step descent. Intra-rater reliability of goniometer-assessed Trendelenburg POF and agreement with motion analysis-assessed POF were analyzed. Pearson's r was used to determine the relationships between Trendelenburg POF and hip abduction strength with peak POF during each functional activity. RESULTS: Goniometer-assessed Trendelenburg POF demonstrated very strong reliability (ICC: 0.948), strong agreement with 3D motion analysis (ICC: 0.792), correlated moderately with peak POF during walking (r = 0.519) and step ascent (r = 0.572), and weakly with step descent (r = 0.463). Hip abductor strength correlated weakly with peak POF during step ascent (r = -0.307) and negligibly during walking (r = -0.270) and step descent (r = -0.249). CONCLUSIONS: Goniometer-assessed Trendelenburg POF was reliable, agreed with motion analysis, and may provide insight into hip abduction muscle performance during functional activities in people with MS.

Maximal daily stepping cadence partially explains functional capacity of individuals with end-stage knee osteoarthritis.

BACKGROUND: Individuals with end-stage knee osteoarthritis (OA) walk at a lower intensity (ie, slower step cadence) contributing to worse physical function. Previous literature reports daily step counts and sedentary time, with little information regarding stepping bouts or cadence. Determining relationships between daily higher stepping cadence duration and clinical outcomes can move the field toward optimal daily stepping prescription. OBJECTIVE: To quantify daily physical activity patterns of individuals with end-stage knee OA and determine the contribution of high stepping cadence to explain functional capacity variability. DESIGN: Cross-sectional analysis. SETTING: Veterans Administration medical center. PARTICIPANTS: U.S. military veterans (n = 104; age: 67.1 years [7.2]; mean [SD]; male [89.3%]) with end-stage knee OA were enrolled. INTERVENTION: Not applicable. MAIN OUTCOME MEASURE: Functional capacity (6-Minute Walk Test [6MWT]). Physical activity (activPAL wearable sensor; cadence and time sitting, standing, and stepping), pain (Western Ontario and McMaster Universities Osteoarthritis Index-pain subscale) sociodemographic variables, and comorbidities (body mass index and Functional Comorbidity Index) are the main explanatory variables. RESULTS: Participants' wake time was mainly sitting (11.0 h/day) in ≥60-minute bouts (29.7% ± 12.7 of sitting time). Standing (3.4 hours/day) and stepping (1.4 h/day) primarily occurred in 0-5 minute bouts (standing: 87.7% ± 14.4 of standing time, stepping: 98.7% ± 12.7 of stepping time) and stepping cadence was predominantly incidental (1-19 spm; 52.9% ± 9.6 of total stepping time). Backward elimination model results indicated shorter medium-to-brisk cadence bout duration, older age, and higher pain significantly explained shorter 6MWT distance (Adj R2 =0.24, p < .01). CONCLUSIONS: Individuals with knee OA spend most of their waking hours sitting, while standing and stepping occurs in short bouts at very low stepping cadence. Decreased time in high stepping cadence is associated with lower functional capacity. Future studies should explore if increasing the daily time spent in higher step cadence can improve functional capacity in this population.

Prematriculation Predictors of Academic Difficulties During the First Year of a Doctor of Physical Therapy Program.

PURPOSE: To analyze the ability of pre-matriculation metrics to predict difficulties during the first year of a Doctor of Physical Therapy (DPT) program with a pass-fail grading system. METHODS: Undergraduate cumulative, science, and pre-requisite grade point averages (GPAs) and verbal and quantitative Graduate Record Examination (GRE) percentiles were collected during the admissions process of 190 students in an accredited DPT program at a southeastern US private university between 2019-2021. Students were dichotomized to groups with and without academic difficulties in coursework and a first-year comprehensive assessment (CA). Independent t-tests identified differences between groups, and logistic regression analyses identified predictors of academic difficulties. Receiver operating characteristic (ROC) curve analyses were performed to identify cut-off scores and risk ratios were calculated. RESULTS: Students with coursework difficulties had lower verbal (d=0.36, p=0.009) and quantitative (d=0.31, p=0.02) GRE scores. Verbal GRE scores were also lower in students who failed the CA (p=0.049). Students who scored less than the 47th percentile on the verbal GRE were 53% more likely to have academic difficulties and 4.2 times more likely to fail the CA than those who scored in the 70th percentile or higher. CONCLUSION: Verbal GRE percentile best predicted academic difficulty in the first year of a DPT program.

Including cognitive assessments with functional testing predicts capabilities relevant to everyday walking in older adults.

BACKGROUND: Dual-task (DT) testing reflects real-world walking demands in older adults but is not always feasible to perform in clinic. Whether clinical measures that predict single-task (ST) performance also predict DT performance or dual-task effects (DTEs) has not been fully explored. RESEARCH QUESTION: What are the relationships between cognitive performance, functional mobility, and self-reported physical activity and balance confidence and ST and DT Gait Speed and Cognitive Reaction Time, as well as DTEs on Gait Speed (DTEGS) and Cognitive Reaction Time (DTERT), in older adults? METHODS: Sixty-two older adults (71.5 ± 7.1 years, 17 males) completed cognitive performance, functional mobility, and self-report physical activity and balance confidence assessments. Three 1-min trials were performed: 1) ST Cognition (clock task), 2) ST Gait and 3) DT Cognition + Gait, with Cognitive Reaction Time (recorded during clock task performance via DirectRT) and Gait Speed (measured during walking trial via APDM system) recorded, and DTEGS and DTERT calculated, as the cognitive and gait outcomes. Six multivariate regressions were conducted to test whether cognitive performance, functional mobility, and self-report assessments predicted Gait Speed and Cognitive Reaction Time in ST and DT conditions and DTEs. RESULTS: The Comprehensive Trail Making Test (CTMT) predicted Reaction Time in ST cognitive (ß = - 0.525, p = .003) and DT (ß = - 0.510, p = .006) trials. The Physical Activity Scale for the Elderly (PASE) predicted DTERT (ß = - 0.397, p = .008). The 10-Meter Walk Test (10MWT) predicted Gait Speed in ST gait (ß = 0.692, p < .001) and DT (ß = 0.715, p < .001) trials. The Four Square Step Test (FSST) predicted ST Gait Speed (ß = - 0.233, p = .034). The Montreal Cognitive Assessment (MoCA) (ß = 0.293, p = .027), 10MWT (ß = 0.322, p = .046), and the FSST (ß = 0.378, p = .019) predicted DTEGS. SIGNIFICANCE: The 10MWT, CTMT, and MoCA can be easily implemented in the clinic and may be good choices to assess cognitive and functional abilities necessary for ambulation in older adults.

Feasibility of repeated session error-augmentation gait training for people with nontraumatic transtibial amputation.

BACKGROUND: Spatiotemporal gait asymmetries are a persistent problem for people with non-traumatic lower-limb amputation. To date, there is limited knowledge of multi-session gait training interventions targeting step length symmetry after non-traumatic amputation. OBJECTIVE: The objective was to evaluate the feasibility and efficacy of an eight-session, treadmill-based error-augmentation gait training (EAT) protocol to improve spatiotemporal gait asymmetry in people with non-traumatic transtibial amputation (TTA). STUDY DESIGN: Pre-post, single group. Methods: The EAT protocol involved eight training sessions (twice per week, four weeks) of supervised split-belt treadmill walking with asymmetrical belt speeds for five, three-minute sets each session. Step length symmetry during overground walking at a self-selected gait speed was assessed prior to, weekly, and one-week after the EAT protocol. Feasibility outcomes included protocol fidelity, safety, participant acceptability, and efficacy. RESULTS: Seven of the eight participants (87.5%) completed the intervention at the prescribed dose. One participant developed a skin blister on their residual limb, which was possibly related to the intervention. No falls, musculoskeletal injuries, or increases in pain occurred. Participants rated EAT as acceptable based on scores on the Intrinsic Motivation Inventory - Interest/Enjoyment subscale (6.6 ± 0.5; mean ± SD). Average between-limb step length Normalized Symmetry Index improved (was reduced) one-week following EAT (2.41 ± 6.6) compared to baseline (5.47 ± 4.91) indicating a moderate effect size (d=0.53). CONCLUSIONS: An eight session EAT program delivered over four weeks using a split-belt treadmill is feasible for people with unilateral non-traumatic TTA and may reduce step length asymmetry up to a week after intervention.

Movement compensations during a step ascent task are associated with stair climbing performance in people with multiple sclerosis.

BACKGROUND: The biomechanical mechanisms underlying stair climbing limitations are poorly understood in people with multiple sclerosis (MS). RESEARCH QUESTIONS: Are trunk and pelvis motion and lower extremity joint moments during step ascent different between MS and control groups? Are step ascent biomechanics and stair climbing performance associated in people with MS? METHODS: 20 people with MS (49 ±â€¯12 years, EDSS range: 1.5-5.5) and ten control participants (48 ±â€¯12 years) underwent three-dimensional motion analysis while ascending a 15.2-cm step and also completed a timed Functional Stair Test. Main effects of group (MS vs Control) and limb (Stronger/Dominant vs Weaker/Non-dominant) and interactions were assessed using two-way analyses of variance. Associations between movement patterns during the step ascent and Functional Stair Test performance were performed using Pearson's correlations and backward stepwise linear regression. RESULTS: Significant group main effects were observed in greater sagittal pelvis excursion (p < 0.001), greater sagittal (p = 0.013) and frontal (p = 0.001) trunk excursion, and lower trail limb peak ankle plantar flexion moment (p < 0.001) of the MS group. Significant limb main effects were observed with greater sagittal trunk excursion (p = 0.037) and peak trail limb ankle plantar flexion moment (p = 0.037) in the stronger/dominant limb. A significant interaction was observed in peak knee extensor moment (p = .002). Stair climbing performance in the MS group correlated with sagittal (r = .607, p=<0.001) and frontal pelvis excursions (r = 0.385, p = 0.014), sagittal trunk excursion (r = .411, p = 0.008), and ankle plantar flexion moments (r=-0.415, p = 0.008). Sagittal and frontal pelvis excursion and bilateral handrail use explained a significant amount of variability in stair climbing performance (Adj R2 = 0.775). SIGNIFICANCE: In conclusion, despite the presence of proximal and distal lower extremity movement pattern compensations during a step ascent task, larger pelvis angular excursions are associated with impaired stair climbing performance in people with MS and may serve as targets for future rehabilitation interventions.

Patterns of Sitting, Standing, and Stepping After Lower Limb Amputation.

OBJECTIVE: The objectives of this study were to describe sitting, standing, and stepping patterns for people with lower limb amputation (LLA) and to compare sitting, standing, and stepping between people with dysvascular LLA and people with traumatic LLA. METHODS: Participants with dysvascular or traumatic LLA were included if their most recent LLA was at least 1 year earlier, they were ambulating independently with a prosthesis, and they were between 45 and 88 years old. Sitting, standing, and stepping were measured using accelerometry. Daily sitting, standing, and stepping times were expressed as percentages of waking time. Time spent in bouts of specified durations of sitting (<30, 30-60, 60-90, and >90 minutes), standing (0-1, 1-5, and >5 minutes), and stepping (0-1, 1-5, and >5 minutes) was also calculated. RESULTS: Participants (N = 32; mean age = 62.6 [SD = 7.8] years; 84% men; 53% with dysvascular LLA) spent most of the day sitting (median = 77% [quartile 1 {Q1}-quartile 3 {Q3} = 67%-84%]), followed by standing (median = 16% [Q1-Q3 = 12%-27%]) and stepping (median = 6% [Q1-Q3 = 4%-9%]). One-quarter (median = 25% [Q1-Q3 = 16%-38%]) of sitting was accumulated in bouts of >90 minutes, and most standing and stepping was accrued in bouts of <1 minute (standing: median = 42% [Q1-Q3 = 34%-54%]; stepping: median = 98% [Q1-Q3 = 95%-99%]). Between-etiology differences included proportion of time sitting (traumatic: median = 70% [Q1-Q3 = 59%-78%]; dysvascular: median = 79% [Q1-Q3 = 73%-86%]) and standing (traumatic: median = 23% [Q1-Q3 = 16%-32%]; dysvascular: median = 15% [Q1-Q3 = 11%-20%]). CONCLUSION: Participants had high daily volumes of long durations of sitting. Further, these individuals accumulated most physical activity in bouts of <1 minute. IMPACT: High levels of sedentary behavior and physical inactivity patterns may place people with LLA at greater mortality risk relative to the general population. Interventions to minimize sedentary behaviors and increase physical activity are potential strategies for improving poor outcomes of physical therapy after LLA.