Hollman, John

The purpose of this study was to assess the correlations of acceleration measurements between an instrumented hockey helmet and the Hybrid III headform and to determine whether collision with a broad surface affects the correlations between these data. A CCM Vector hockey helmet, instrumented with the Head Impact Telemetry System, was fitted onto an instrumented Hybrid III headform and dropped onto an inclined plate to simulate impacts in hockey. The helmet and headform were dropped from 0.15, 0.30, and 0.60 m at different orientations to create impacts to the vertex, occipital, right, left, and forehead surfaces. Peak linear and rotational acceleration magnitudes and head injury criteria were assessed for each system. Correlations were assessed with the Pearson correlation coefficient, and linear regression models were generated. Relative error was assessed, and results were compared with the Wilcoxon signed rank test. Peak acceleration magnitudes generally had strong mathematical correlations, although a 1:1 linear relationship for rotational acceleration data was not observed. Differences between helmet and head peak acceleration magnitudes were significant. The linear relationship varied according to the impact direction. Instrumented helmet and head data demonstrated a strong mathematical correlation, but measures of linear acceleration generally had better 1:1 agreement than rotational acceleration measures. There is some dependence in the relationship between the helmet and head data on the impact direction, with vertex strikes showing the weakest correlation. Although data generated from the helmet may be useful for interpreting head accelerations experienced by on-ice players, additional analysis of the time-series data should be performed to understand its full utility.

Objectives To determine the cross‐sectional association between cerebral amyloid‐beta (A β ) deposition and gait. Design Cross‐sectional. Setting Population‐based cohort study in Olmsted County, MN . Participants Cognitively normal individuals (n = 611), aged 50 to 69 years, enrolled in the Mayo Clinic Study of Aging with concurrent PiB‐ PET imaging and gait assessment. Participants with a history of stroke, alcoholism, Parkinson's disease, subdural hematoma, traumatic brain injury, or normal pressure hydrocephalus were excluded. Measurements PiB‐ PET SUVR was measured in prefrontal, orbitofrontal, parietal, temporal, anterior cingulate, posterior cingulate, and motor‐specific regions of interest ( ROI s). Gait parameters (speed, cadence, stride length, double support time, and intra‐individual stance time variability) were measured using GAITR ite ® instrumentation. Linear regression models were adjusted for age, sex, body mass index, education, APOE ε 4 allele, Charlson comorbidity index, and depression. In secondary analyses, we additionally adjusted for neurodegeneration (hippocampal volume, FDG PET SUVR , and cortical thickness) in AD ‐associated regions. Results In fully adjusted models including neuroimaging measures of neurodegeneration, higher PiB‐ PET SUVR across all ROI s was associated with slower gait speed ( P < .05 except for the parietal ROI ), lower cadence and longer double support time ( P ≤ .05 except for the motor ROI ), and greater stance time variability ( P < .05). In sex‐stratified analyses, the association between higher PiB‐ PET SUVR across all ROI s and measures of gait was only present among women. Conclusion PiB‐ PET SUVR across ROI s, independent of general measures of AD ‐associated neurodegeneration, is associated with poorer performance on multiple gait parameters among cognitively normal women, aged 50 to 69 years. Longitudinal studies are needed to determine whether A β predicts gait decline in both women and men.

Background: Previous studies reported that slower gait speed might predict cognitive impairment and dementing illnesses, supporting the role of gait speed as a possible subclinical marker of cognitive impairment. However, the predictive value of other gait parameters for cognitive decline is unclear. Objective: To investigate and compare the association with, and prediction of, specific gait parameters for cognition in a population-based sample. Methods: The analysis included 3,426 cognitively normal participants enrolled in the Mayo Clinic Study of Aging. At baseline and every 15 months (mean follow-up = 1.93 years), participants had a study coordinator evaluation, neurological examination, and a neuropsychological assessment using nine tests that covered four domains. Gait parameters were assessed with the GAITRite ® instrument. General linear mixed effects models were used to compute the annualized rate of change in cognitive domain z-scores, controlling for age, sex, education, depression, comorbidities, body mass index, APOE ɛ 4 allele, and visit number, and excluding individuals with a history of stroke, alcoholism, Parkinson’s disease, subdural hematoma, and normal pressure hydrocephalus. Results: Spatial (stride length), temporal (ambulatory time, gait speed, step count, cadence, double support time), and spatiotemporal (cadence) gait parameters, and greater intraindividual variability in stride length, swing time, and stance time were associated with a significant decline in global cognition and in specific domains including memory, executive function, visuospatial, and language. Conclusions: Spatial, temporal, and spatiotemporal measures of gait and greater variability of gait parameters were associated with and predictive of both global- and domain-specific cognitive decline.

Background: Strengthening of core hip, trunk, and abdominal muscles has been utilized with injury prevention and low back pain and has the potential to improve athletic performance. Hypothesis: During a side-bridge, trunk and thigh muscles on the ipsilateral weightbearing side would produce greater activation than their counterparts on the contralateral nonweightbearing side. Study Design: Descriptive laboratory study. Methods: Twelve females and 13 males participated. Electromyography (EMG) signals were gathered for 5 right-sided muscles (rectus abdominis [RA], external oblique [EO], longissimus thoracis [LT], lumbar multifidus [LM], and gluteus medius [GM]) during 3 repetitions of 4 side-bridging exercises (trunk-elevated side support [TESS], foot-elevated side support [FESS], clamshell, and rotational side-bridge [RSB]) performed bilaterally in random order using surface electrodes. EMG signals were normalized to peak activity in maximum voluntary isometric contraction (MVIC) trials and expressed as a percentage. Descriptive EMG data were calculated for EMG recruitment (% MVIC) and compared between right side up and right side down conditions and between exercises with 2-way repeated-measures analyses of variance at α = 0.05. Results: RSB created the most muscle activation in 3 of 4 recorded trunk muscles (RA, 43.9% MVIC; EO, 62.8 % MVIC; and LT, 41.3% MVIC). Activation of the GM exceeded 69% MVIC for TESS, FESS, and RSB. With the exception of the RA in RSB and LT in TESS, recruitment within muscles of the ipsilateral weightbearing trunk and thigh (% MVIC) was significantly greater than their counterparts on the nonweightbearing trunk and thigh for all muscles during the side-bridge exercise conditions. Conclusion: Muscle recruitment was greater within muscles of the ipsilateral weightbearing trunk and thigh for all examined muscles except RA during RSB and LT during TESS. Activation at or above 50% MVIC is needed for strengthening. Activation of the GM and EO meets these requirements. Clinical Relevance: Side-bridge exercises appear to provide strengthening benefits to core hip, trunk, and abdominal muscles on the ipsilateral weightbearing side.

AbstractPurposeAssessment of hip internal rotation (IR) is a critical element in the evaluation of a painful hip, yet there currently exists no consistent method of determining this measurement. The purpose of this study is to report the intra‐rater and inter‐rater reliability of active and passive hip IR measurement using a digital inclinometer.MethodsTwenty‐five subjects (8 men, 17 women) with asymptomatic hip joints, and no known pathology between the ages of 22 and 42 participated. Two examiners measured hip IR for each subject using a digital inclinometer while visually monitoring pelvic motion. Measurements included passive IR, active IR, and active IR while internally rotating both legs simultaneously. Statistical analysis was performed including intra‐rater and inter‐rater reliability.ResultsThere was no significant difference in measured IR values. Mean range of motion values for all techniques and both examiners ranged from 30.7° to 32.8°. Intra‐rater reliability for examiner 1 ranged from 0.84 to 0.92. Inter‐rater reliability ranged from 0.89 to 0.93. Of the methods utilized, active IR of a single leg was the most responsive technique with a minimal detectable change value of 5.4°.ConclusionsClinical assessment of hip IR range of motion can be performed efficiently and reliably with a digital inclinometer along with visual monitoring of the pelvis for unwanted motion. Findings from this study support unilateral active hip IR in a seated position as a reliable and responsive technique for obtaining hip IR measurements.Level of evidenceIII.

ABSTRACT Many people with rapid eye movement (REM) sleep behavior disorder (RBD) have an underlying synucleinopathy, the most common of which is Lewy body disease. Identifying additional abnormal clinical features may help in identifying those at greater risk of evolving to a more severe syndrome. Because gait disorders are common in the synucleinopathies, early abnormalities in gait in those with RBD could help in identifying those at increased risk of developing overt parkinsonism and/or cognitive impairment. We identified 42 probable RBD subjects and 492 controls using the Mayo Sleep Questionnaire and assessed gait velocity, cadence, and stride dynamics with an automated gait analysis system. Cases and controls were similar in age (79.9 ± 4.7 and 80.1 ± 4.7, P = 0.74), Unified Parkinson's Disease Rating Scale Part III (UPDRS) score (3.3 ± 5.5 and 1.9 ± 4.1, P = 0.21) and Mini–Mental State Examination scores (27.2 ± 1.9 and 27.7 ± 1.6, P = 0.10). A diagnosis of probable RBD was associated with decreased velocity (−7.9 cm/s; 95% confidence interval [CI], −13.8 to −2.0; P < 0.01), cadence (−4.4 steps/min; 95% CI, −7.6 to −1.3; P < 0.01), significantly increased double limb support variability (30%; 95% CI, 6–60; P = 0.01), and greater stride time variability (29%; 95% CI, 2–63; P = 0.03) and swing time variability (46%; 95% CI, 15–84; P < 0.01). Probable RBD is associated with subtle gait changes prior to overt clinical parkinsonism. Diagnosis of probable RBD supplemented by gait analysis may help as a screening tool for disorders of α‐synuclein. © 2013 International Parkinson and Movement Disorder Society

Medical professionals and public consumers expect that new physical therapy graduates possess cognitive, technical, and behavioral skills required to provide safe and high‐quality care to patients. The purpose of this study was to determine if a repertoire of ten professional behaviors assessed at the beginning of doctorate of physical therapy education and before the first significant clinical internship could be enhanced in a semester course in gross human anatomy using individual formative feedback. During the human anatomy course, 28 first‐year physical therapy students completed six biweekly, anonymous self‐ and peer assessment surveys that targeted ten professional behaviors important to physical therapists. All professional behaviors were assessed using a five‐point Likert scale. Feedback reports occurred at week eight (mid‐semester) and week 16 (end‐of‐semester) and comprised the direct intervention components of this study. At the midpoint of the semester, professional behavior scores and narrative comments from weeks two, four, and six were compiled and shared with each student by one of three faculty members in a feedback session. Students then submitted biweekly self‐and peer professional behavior assessments (weeks 10, 12, and 14) for the remainder of the human anatomy course. Differences between preintervention and postintervention scores for each of the ten professional behaviors were compared using the Wilcoxon signed‐ranks test. Upon receiving mid‐semester individual feedback, students demonstrated significant improvement in each of the ten professional behaviors. Results from this study indicated a gross anatomy laboratory dissection experience during the first academic semester provided an effective opportunity for teaching and assessing professional behaviors of doctoral students in physical therapy. Anat Sci Educ 6: 324–331. © 2013 American Association of Anatomists.

AbstractPurposeThe primary purpose of this study was to investigate the intra‐tester and inter‐tester reliability of the dial test using a handheld digital inclinometer. Additionally, we examined the responsiveness of the test, and side‐to‐side differences for meaningful comparison.Materials/methodsTwenty‐four healthy subjects (22.5 ± 2.8 years) participated in the study. The dial test was performed on both knees at 30° and 90° of knee flexion with the subject supine. While maintaining a neutral position of the ankle, an inclinometer was positioned parallel to the medial border of the foot to quantify external rotation of the tibia. Two examiners performed the dial test in a blinded manner. The minimal detectable change across repeated measures and side‐to‐side difference was calculated.ResultsIntra‐tester reliability for examiner 1 (E1) was 0.83 at 30° knee flexion and 0.89 at 90° knee flexion. Reliability values for examiner 2 (E2) were 0.86 at 30° and 0.87 at 90° knee flexion. Inter‐tester reliability was 0.74 at 30° and 0.83 at 90°. The minimal detectable change (MDC) for E1 at 30° was ±9.4° and ±7.4° at 90°. For E2, the MDC value was ±9.1° at 30° and ±8.3° at 90°. Ninety‐five percent limits of agreement for side‐to‐side difference was 16.1° and 11.3° ° for E1 at 30° and 90° and for E2 13.9° at 30° and 14.1° at 90°.ConclusionsThis instrumented dial test using a handheld digital inclinometer to measure external rotation can be performed with acceptable reliability in the clinical setting. A difference of 10° between two measurements on the same knee suggests that a meaningful change has occurred. For right to left comparison, differences greater than 15° suggest clinical significance.Level of evidenceIII.

Background: Invasive leg compartment testing may be performed to diagnose chronic exertional compartment syndrome. No prior study has assessed the accuracy of leg compartment needle tip access. Purpose: This study was undertaken to describe and determine the accuracy of palpation-guided and ultrasound-guided techniques for needle tip placement into the deep and superficial posterior leg compartments by a less experienced clinician and a more experienced clinician using a cadaveric model. Study Design: Controlled laboratory study. Methods: Twenty unembalmed adult lower limb cadaveric specimens were used for the study. Two investigators, a sports medicine fellow with 10 months of musculoskeletal ultrasound experience and a staff physiatrist with 3 years of musculoskeletal ultrasound experience, each performed 1 palpation-guided and 1 ultrasound-guided colored latex dye injection into the deep and superficial posterior leg compartments of each cadaveric specimen. A blinded investigator dissected the specimens and graded them for accuracy. Results: The accuracy rates of palpation-guided (accuracy rate, 90%; 95% confidence interval [CI], 76%-97%) and ultrasound-guided (accuracy rate, 88%; 95% CI, 73%-95%) deep posterior compartment injections were statistically equivalent ( P = 1.000). All 80 injections performed into the superficial posterior compartment were accurate (accuracy rate, 100%; 95% CI, 89%-100%). The accuracy of the less experienced investigator (total injection accuracy rate, 88%; 95% CI, 73%-95%) and the more experienced investigator (total injection accuracy rate, 90%; 95% CI, 76%-97%) were not significantly different ( P = 1.000). Conclusion: Needle tip placement into the deep and superficial posterior leg compartments is relatively accurate with palpation guidance regardless of level of experience, and does not improve with the use of ultrasound guidance. Clinical Relevance: Ultrasound guidance does not appear to be indicated for routine deep or superficial posterior leg compartment pressure testing. However, this does not preclude the need for ultrasound guidance in selected clinical scenarios.