Physical Therapy
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Item Open Access Measuring Exercise Capacity and Physical Function in Adult and Older Mice(2021) Graber, Ted G.; Maroto, Rosario; Fry, Christopher S.; Brightwell, Camille R.; Rasmussen, Blake B.Item Open Access Transfection and Activation of CofActor, a Light and Stress Gated Optogenetic Tool, in Primary Hippocampal Neuron Cultures(2021) Bunner, Wyatt P.; Dodson, Rachel; Szatmari, Erzsebet M.; Hughes, Robert M.Item Open Access Cognitive-Motor Interference Heightens the Prefrontal Cortical Activation and Deteriorates the Task Performance in Children With Hemiplegic Cerebral Palsy(2021-02) Surkar, Swati M.; Hoffman, Rashelle M.; Harbourne, Regina; Kurz, Max J.Item Open Access ADAP 1/Centaurin-α1 Negatively Regulates Dendritic Spine function and Memory Formation in the Hippocampus(2021) Szatmari, Erzsebet M.; Moran, Corey; Cohen, Sarah S.; Jacob, Amanda; Parra-Bueno, Paula; Kamasawa, Naomi; Guerrero-Given, Debbie; Klein, Michael; Stackman Jr, Robert; Yasuda, RyoheiItem Open Access Walking Velocity and Step Length Adjustments Affect Knee Joint Contact Forces in Healthy Weight and Obese Adults(2018-05-24) Willson, John; Meardon, Stacey A.Item Open Access Patellofemoral Joint and Achilles Tendon Loads During Overground and Treadmill Running(2016-08-01) Willson, JohnItem Open Access PI3K mediated activation of GSK‑3β reduces at‑level primary afferent growth responses associated with excitotoxic spinal cord injury dysesthesias(2015-06-21) Bareiss, Sonja; Dugan, Elizabeth; Brewer, Kori L.Background Neuropathic pain and sensory abnormalities are a debilitating secondary consequence of spinal cord injury (SCI). Maladaptive structural plasticity is gaining recognition for its role in contributing to the development of post SCI pain syndromes. We previously demonstrated that excitotoxic induced SCI dysesthesias are associated with enhanced dorsal root ganglia (DRG) neuronal outgrowth. Although glycogen synthase kinase-3β (GSK-3β) is a known intracellular regulator neuronal growth, the potential contribution to primary afferent growth responses following SCI are undefined. We hypothesized that SCI triggers inhibition of GSK-3β signaling resulting in enhanced DRG growth responses, and that PI3K mediated activation of GSK-3β can prevent this growth and the development of at-level pain syndromes. Results Excitotoxic SCI using intraspinal quisqualic acid (QUIS) resulted in inhibition of GSK-3β in the superficial spinal cord dorsal horn and adjacent DRG. Double immunofluorescent staining showed that GSK-3βP was expressed in DRG neurons, especially small nociceptive, CGRP and IB4-positive neurons. Intrathecal administration of a potent PI3-kinase inhibitor (LY294002), a known GSK-3β activator, significantly decreased GSK-3βP expression levels in the dorsal horn. QUIS injection resulted in early (3 days) and sustained (14 days) DRG neurite outgrowth of small and subsequently large fibers that was reduced with short term (3 days) administration of LY294002. Furthermore, LY294002 treatment initiated on the date of injury, prevented the development of overgrooming, a spontaneous at-level pain related dysesthesia. Conclusions QUIS induced SCI resulted in inhibition of GSK-3β in primary afferents and enhanced at-level DRG intrinsic growth (neurite elongation and initiation). Early PI3K mediated activation of GSK-3β attenuated QUIS-induced DRG neurite outgrowth and prevented the development of at-level dysesthesias.Item Open Access A pathomechanical paradigm for treating the injured runner(2013) Willy, Richard W.Pathological mechanics are thought to play a role in many common running injuries. A review of the biomechanical literature reveals that a given running injury may be associated with multiple faulty running mechanics. Traditional rehabilitation programs have focused their efforts on addressing the injured anatomical structure. By focusing rehabilitation programs on correcting the pathomechanics of an injury, outcomes may be improved. Since the underlying faulty mechanics have been addressed, risk of reinjury may also be decreased. In this article, a pathomechanical paradigm for the treatment of the injured runner is introduced. Emphasis is placed on recognizing the most common types of faulty running mechanics often encountered in the clinical setting and their implications for injury. Finally, suggested treatment techniques are described.Item Open Access Varied response to mirror gait retraining of gluteus medius control, hip kinematics, pain, and function in 2 female runners with patellofemoral pain.(2013-12) Willy, Richard W.; Davis, Irene S.STUDY DESIGN: Case report. BACKGROUND: The underlying mechanism of the changes in running mechanics after gait retraining is presently unknown. This case report assesses changes in muscle coordination and kinematics during treadmill running and step ascent in 2 female runners with patellofemoral pain after mirror gait retraining. CASE DESCRIPTION: Two female runners with chronic patellofemoral pain underwent 8 sessions of mirror gait retraining during treadmill running. Subjective measures and hip abductor strength were recorded at baseline and after the retraining phase. Changes in hip mechanics and electromyography data of the gluteus medius during treadmill running and step ascent were also assessed. OUTCOMES: Both runners reported improvements in pain and function that were maintained for at least 3 months. During running, peak contralateral pelvic drop (baseline-postretraining difference: runner 1, 2.6° less; runner 2, 1.7° less) and peak hip adduction (baseline-postretraining difference: runner 1, 5.2° less; runner 2, 6.3° less) were reduced after retraining. Kinematic reductions accompanied earlier activation of the gluteus medius relative to foot strike (baseline-postretraining difference: runner 1, 12.6 milliseconds earlier; runner 2, 37.3 milliseconds earlier) and longer duration of gluteus medius activity (runner 1, 55.8 milliseconds longer; runner 2, 44.4 milliseconds longer). Runner 1 transferred reduced contralateral pelvic drop to step ascent, whereas runner 2 did not (contralateral pelvic drop baseline-postretraining difference: runner 1, 3.6° less; runner 2, 1.5° more; hip adduction baseline-postretraining difference: runner 1, 3.0° less; runner 2, 0.5° more). Both runners demonstrated earlier onset of gluteus medius activity during step ascent (baseline-postretraining difference: runner 1, 48.0 milliseconds earlier; runner 2, 28.3 milliseconds earlier), but only runner 1 demonstrated longer activation duration (runner 1, 25.0 milliseconds longer; runner 2, 69.4 milliseconds shorter). DISCUSSION: While changes in hip mechanics and gluteus medius activity during running were consistent with those noted during step ascent for runner 1, runner 2 failed to demonstrate similar consistency between the tasks. Earlier onset and longer duration of gluteus medius activity may have been necessary to alter step mechanics for runner 2. LEVEL OF EVIDENCE: Therapy, level 4. NOTE: This is a non-final version of an article published in final form in Willy, R. W., & Davis, I. S. (2013). Varied response to mirror gait retraining of gluteus medius control, hip kinematics, pain, and function in 2 female runners with patellofemoral pain. The Journal of Orthopaedic and Sports Physical Therapy, 43(12), 864-874. doi:10.2519/jospt.2013.4516Item Open Access Mirror gait retraining for the treatment of patellofemoral pain in female runners.(2012-12) Willy, Richard W.; Scholz, John P.; Davis, Irene S.BACKGROUND: Abnormal hip mechanics are often implicated in female runners with patellofemoral pain. We sought to evaluate a simple gait retraining technique, using a full-length mirror, in female runners with patellofemoral pain and abnormal hip mechanics. Transfer of the new motor skill to the untrained tasks of single leg squat and step descent was also evaluated. METHODS: Ten female runners with patellofemoral pain completed 8 sessions of mirror and verbal feedback on their lower extremity alignment during treadmill running. During the last 4 sessions, mirror and verbal feedback were progressively removed. Hip mechanics were assessed during running gait, a single leg squat and a step descent, both pre- and post-retraining. Subjects returned to their normal running routines and analyses were repeated at 1-month and 3-month post-retraining. Data were analyzed via repeated measures analysis of variance. FINDINGS: Subjects reduced peaks of hip adduction, contralateral pelvic drop, and hip abduction moment during running (P<0.05, effect size=0.69-2.91). Skill transfer to single leg squatting and step descent was noted (P<0.05, effect size=0.91-1.35). At 1 and 3 months post retraining, most mechanics were maintained in the absence of continued feedback. Subjects reported improvements in pain and function (P<0.05, effect size=3.81-7.61) and maintained through 3 months post retraining. INTERPRETATION: Mirror gait retraining was effective in improving mechanics and measures of pain and function. Skill transfer to the untrained tasks of squatting and step descent indicated that a higher level of motor learning had occurred. Extended follow-up is needed to determine the long term efficacy of this treatment.Item Open Access Are mechanics different between male and female runners with patellofemoral pain?(2012-11) Willy, Richard W.; Davis, Irene S.; Manal, Kurt T.; Witvrouw, Erik E.;INTRODUCTION: Patellofemoral pain (PFP) has often been attributed to abnormal hip and knee mechanics in females. To date, there have been few investigations of the hip and knee mechanics of males with PFP. The purpose of this study was to compare the lower extremity mechanics and alignment of male runners with PFP with healthy male runners and female runners with PFP. We hypothesized that males with PFP would move with greater varus knee mechanics compared with male controls and compared with females with PFP. Furthermore, it was hypothesized that males with PFP would demonstrate greater varus alignment. METHODS: A gait and single-leg squat analysis was conducted on each group (18 runners per group). Measurement of each runner's tibial mechanical axis was also recorded. Motion data were processed using Visual 3D (C-Motion, Bethesda, MD). ANOVAs were used to analyze the data. RESULTS: Males with PFP ran and squatted in greater peak knee adduction and demonstrated greater peak knee external adduction moment compared with healthy male controls. In addition, males with PFP ran and squatted with less peak hip adduction and greater peak knee adduction compared with females with PFP. The static measure of mechanical axis of the tibial was not different between groups. However, a post hoc analysis revealed that males with PFP ran with greater peak tibial segmental adduction. CONCLUSION: Males with PFP demonstrated different mechanics during running and during a single-leg squat compared with females with PFP and with healthy males. Based upon the results of this study, therapies for PFP may need to be sex specific. NOTE: This is a non-final version of an article published in final form in Medicine & Science in Sports & Exercise 44, no. 11 (Nov 2012): 2165-2171.Item Open Access Kinematic and kinetic comparison of running in standard and minimalist shoes(2013-07) Willy, Richard W.; Davis, Irene S.The purpose of this study was to determine if running in a minimalist shoe results in a reduction in ground reaction forces and alters kinematics over standard shoe running. The secondary purpose of this study was to determine if within–session accommodation to a novel minimalist shoe occurs. Running in a minimalist shoe appears to, at least in the short–term, increase loading of the lower extremity over standard shoe running. The accommodation period resulted in less favorable landing mechanics in both shoes. These findings bring into question whether minimal shoes will provide enough feedback to induce an alteration that is similar to barefoot running.Item Open Access The Effect of a Hip Strengthening Program on Mechanics during Running and Single Leg Squatting(2011-07) Willy, Richard W.; Davis, Irene S.STUDY DESIGN: Block randomized controlled trial. OBJECTIVES: To investigate whether a strengthening and movement education program, targeting the hip abductors and hip external rotators, alters hip mechanics during running and during a single-leg squat. BACKGROUND: Abnormal movement patterns during running and single-leg squatting have been associated with a number of running-related injuries in females. Therapeutic interventions for these aberrant movement patterns typically include hip strengthening. While these strengthening programs have been shown to improve symptoms, it is unknown if the underlying mechanics during functional movements is altered. METHODS: Twenty healthy females with excessive hip adduction during running, as determined by instrumented gait analysis, were recruited. The runners were matched by age and running distance, and randomized to either a training group or a control group. The training group completed a hip strengthening and movement education program 3 times per week for 6 weeks in addition to single-leg squat training with neuromuscular reeducation consisting of mirror and verbal feedback on proper mechanics. The control group did not receive an intervention but maintained the current running distance. Using a handheld dynamometer and standard motion capture procedures, hip strength and running and single-leg squat mechanics were compared before and after the strengthening and movement education program. RESULTS: While hip abductor and external rotation strength increased significantly (P<.005) in the training group, there were no significant changes in hip or knee mechanics during running. However, during the single-leg squat, hip adduction, hip internal rotation, and contralateral pelvic drop all decreased significantly (P = .006, P = .006, and P = .02, respectively). The control group exhibited no changes in hip strength, nor in the single-leg squat or running mechanics at the conclusion of the 6-week study. CONCLUSION: A training program that included hip strengthening and movement training specific to single-leg squatting did not alter running mechanics but did improve single-leg squat mechanics. These results suggest that hip strengthening and movement training, when not specific to running, do not alter abnormal running mechanics. LEVEL OF EVIDENCE: Therapy, level 2b. NOTE: This is not the final published version. The final version was published in the Journal of Orthopaedic and Sports Physical Therapy. 2011 Sep; 41(9): 625-32. doi: 10.2519/jospt.2011.3470Item Open Access Lower Extremity Strength and Mechanics During Jumping in Women With Patellofemoral Pain(2009) Willson, John D.; Davis, Irene S.Context: Lower extremity (LE) weakness might be associated with altered mechanics during weight bearing in subjects with patellofemoral pain syndrome (PFPS). Objective: To analyze LE strength, mechanics, and the association between these variables among women with and without PFPS during a simulated athletic task. Design: Case control. Setting: Motion-analysis laboratory. Subjects: 20 women with PFPS and 20 healthy women. Main Outcome Measures: Peak isometric lateral trunk-flexion, hipabduction, hip external-rotation, knee-flexion, and knee-extension strength, as well as hip- and knee-joint excursions and angular impulses during single-leg jumps. Results: PFPS subjects produced less hip-abduction, hip external-rotation, and trunk lateral- flexion force than the control group. The PFPS group also demonstrated greater hipadduction excursion and hip-abduction impulses. The association between the strength measurements and LE mechanics was low. Conclusions: Women with PFPS demonstrate specific weaknesses and altered LE mechanics. Weakness is not, however, highly correlated with observed differences in mechanics. ABSTRACT FROM AUTHORItem Open Access Effects of Medially Wedged Foot Orthoses on Knee and Hip Joint Running Mechanics in Females With and Without Patellofemoral Pain Syndrome.(2013) Boldt, Andrew R.; Willson, John D.; Barrios, Joaquin A.; Kernozek, Thomas W.We examined the effects of medially wedged foot orthoses on knee and hip joint mechanics during running in females with and without patellofemoral pain syndrome (PFPS). We also tested if these effects depend on standing calcaneal eversion angle. Twenty female runners with and without PFPS participated. Knee and hip joint transverse and frontal plane peak angle, excursion, and peak internal knee and hip abduction moment were calculated while running with and without a 6° full-length medially wedged foot orthoses. Separate 3-factor mixed ANOVAs (group [PFPS, control] x condition [medial wedge, no medial wedge] x standing calcaneal angle [everted, neutral, inverted]) were used to test the effect of medially wedged orthoses on each dependent variable. Knee abduction moment increased 3% (P = .03) and hip adduction excursion decreased 0.6° (P < .01) using medially wedged foot orthoses. No significant group x condition or calcaneal angle x condition effects were observed. The addition of medially wedged foot orthoses to standardized running shoes had minimal effect on knee and hip joint mechanics during running thought to be associated with the etiology or exacerbation of PFPS symptoms. These effects did not appear to depend on injury status or standing calcaneal posture. ABSTRACT FROM AUTHORItem Open Access Comparison of Stance Phase Knee Joint Angles and Moments Using Two Different Surface Marker Representations of the Proximal Shank in Walkers and Runners(2013) Willson, John D.; Petit, Daniel J.; Barrios, Joaquin A.Efforts to compare different surface marker configurations in 3-dimensional motion analysis are warranted as more complex and custom marker sets become more common. At the knee, different markers can been used to represent the proximal shank. Often, two anatomical markers are placed over the femoral condyles, with their midpoint defining both the distal thigh and proximal shank segment ends. However, two additional markers placed over the tibial plateaus have been used to define the proximal shank end. For this experiment, simultaneous data for both proximal shank configurations were independently collected at two separate laboratories by different investigators, with one lab capturing a walking population and the other a running population. Common discrete knee joint variables were then compared between marker sets in each population. Using the augmented marker set, peak knee flexion after weight acceptance was less (1.2-1.7°, p<0.02) and peak knee adduction was greater (0.7-1.4°, p<0.001) in both data sets. Similarly, the calculated peak knee flexion moment was less by 15-20% and internal rotation moment was greater by 11-18% (p<0.001). These results suggest that the calculation of knee joint mechanics are influenced by the proximal shank’s segment endpoint definition, independent of dynamic task, investigator, laboratory environment, and population in this study.Item Open Access Kinematic and Electromyographic Analysis of Elbow Flexion During Inertial Exercise(East Carolina University, 1995-09) Tracy, James E.; Obuchi, Shuchi; Johnson, BenInertial exercise protocols are currently used clinically to improve and restore normal muscle function even though research to substantiate their effectiveness cannot be cited in the literature. The purpose of this study was to compare simultaneous kinematic and electromyographic (EMG) data obtained from 12 subjects during elbow flexion on the Impulse Inertial Exercise System. Testing sessions consisted of inertial exercise performed using phasic and tonic techniques with loads of: a) 0 kg, b) 2.27 kg, c) 4.54 kg, d) 6.80 kg, and e) 9.07 kg. Greater peak angular velocities, peak plafform accelerations (change in velocity of plafform during elbow flexion), mean and peak triceps brachii muscle EMG activity, and less range of motion were observed during phasic exercise. There was also a general trend for peak angular velocities and peak plafform acceleration to increase as the load decreased. No significant difference in mean or peak EMG activity of the biceps brachii muscle was seen between techniques. Clinicians and athletic trainers using inertial exercise should consider both the exercise technique and load characteristics when designing protocols to meet the specific needs of patients. Originally published Journal of Athletic Training, Vol. 30, No. 3, Sep 1995Item Open Access Author's Response(East Carolina University, 1996-01) Tracy, James E.