Eric L. Dugan Copyright (c) 2012 All rights reserved. http://works.bepress.com/eric_dugan Recent documents in Eric L. Dugan en-us Sat, 07 Jan 2012 01:35:00 PST 3600 Differences in dominant and non-dominant plant leg kinetics and kinematics during soccer kicking http://works.bepress.com/eric_dugan/25 http://works.bepress.com/eric_dugan/25 Thu, 05 Jan 2012 13:08:10 PST Cassidy M. Berlin et al. Walk –Run Transition Speed and the Relevance of Loading, Muscular Fatigue, and Human Kinematics: A Comparison of Human Gait Patterns http://works.bepress.com/eric_dugan/24 http://works.bepress.com/eric_dugan/24 Thu, 05 Jan 2012 13:07:04 PST Callie E. Gunderson et al. A time-efficient method for analyzing bone strain in large subject pools http://works.bepress.com/eric_dugan/23 http://works.bepress.com/eric_dugan/23 Thu, 05 Jan 2012 13:01:37 PST Daniel Leib et al. Balance, Balance Confidence, and Health-Related Quality of Life in Persons with Chronic Stroke After Body Weight-Supported Treadmill Training http://works.bepress.com/eric_dugan/22 http://works.bepress.com/eric_dugan/22 Wed, 30 Nov 2011 12:46:14 PST Objectives To examine changes in balance, balance confidence, and health-related quality of life immediately and 6 months after body weight–supported treadmill training (BWSTT) for persons with chronic stroke (primary objective) and to determine whether changes in gait speed after BWSTT were associated with changes in these dimensions of health (secondary objective).

Design Prospective pre-/posttest pilot study with 6 months retention.

Setting University research laboratory settings.

Participants A convenience sample of participants (N=19; at least 6mo poststroke; able to ambulate 0.4–0.8m/s) were recruited. Intervention BWSTT was provided for 24 sessions over 8 weeks with 20 minutes of total walking each session.

Main Outcome Measures Berg Balance Scale (BBS), Activities-Specific Balance Confidence (ABC) Scale, Stroke Impact Scale (SIS), comfortable 10-m walk test (CWT), and fast 10-m walk test (FWT). Proportions of participants who achieved minimal detectable changes (MDCs) were examined for all measures.

Results Statistically significant improvements were found from pre- to posttest for BBS, ABC, SIS mobility, SIS stroke recovery, and CWT scores (P<.05) and from pretest to retention on BBS, ABC, CWT, and FWT scores (P<.05). For most participants, improvements did not exceed MDCs. Changes in gait speed and BBS, ABC, and SIS scores were not associated.

Conclusions The findings of this study suggest that effects of BWSTT may transfer beyond gait to positively influence balance, balance confidence, and health-related quality of life. However, for most participants, BWSTT was not sufficient to induce improvements in balance and balance confidence beyond measurement error or long-term retention of enhanced perceptions of quality of life.

]]> Stephanie A. Combs et al. An Integrated Modeling Method for Bone Strain Analysis http://works.bepress.com/eric_dugan/21 http://works.bepress.com/eric_dugan/21 Wed, 30 Nov 2011 12:46:11 PST Stress fracture is a common overuse injury experienced by participants of activities involving repetitive loading such as running and loaded walking. One population especially susceptible to this type of injury is US ARMY recruits. The incidence of stress fracture during basic training is about 6% in recruits [1] with the most common site of fracture being the tibia; these tibial stress fractures account for more than 40% of total stress fractures in the military [2,3].

]]> Daniel Leib et al. Load Carriage Increases Mechanical Loading Rates During Walking http://works.bepress.com/eric_dugan/20 http://works.bepress.com/eric_dugan/20 Wed, 30 Nov 2011 12:46:08 PST Stress fracture is an overuse bone injury. It is a result of excessively repetitive loads acting on the bone over time which leads to fatigue induced bone microdamage [1,2]. Mechanical loading and loading rate are two major factors related to stress fracture development.

]]> He Wang et al. Whole-Body Vibration Effects on Bone Mineral Density in Women with or Without Resistance Training http://works.bepress.com/eric_dugan/19 http://works.bepress.com/eric_dugan/19 Wed, 30 Nov 2011 12:46:05 PST Introduction: Whole-body vibration exposure may translate into improved bone mass in young adult women. The primary focus of this study was to examine the effects of graded whole-body vibration or vibration exposure plus resistance training on bone mineral density (BMD), hematological measures for bone remodeling, and exercise metabolism in young women.

Methods: There were 51 healthy active women [mean (SD) age, 21.02 (3.39) yr; height, 165.66 (6.73) cm; body mass 66.54 (13.39) kg] who participated in the intervention. Subjects were randomly assigned to whole-body vibration (WBV), whole-body vibration plus resistance training (WBV+RT), or control (CONT) groups for 16 wk.

Results: A repeated-measure ANOVA found no significant (P < 0.05) group differences in BMD at the completion of 16 wk. A significant within group change was apparent for the WBV (2.7% femoral neck) and WBV+RT (femoral neck 1.9%; vertebra 0.98%). WBV and WBV+RT experienced a significant (P < 0.05) 60% and 58% increase in adiponectin, 48% and 30% in transforming growth factor-β1, and 17% and 34% in nitric oxide with an accompanying 50% and 36% decrease in osteopontin, 19% and 34% in interleukin-1β, and 38% and 39% in tumor necrosis factor-α.

Conclusions: The results indicate graded whole-body vibration exposure may be effective in improving BMD by increasing bone deposition while also decreasing bone resorption. Whole-body vibration may also provide an efficient stratagem for young women to achieve peak bone mass and help stave off osteoporosis later in life and provide a novel form of physical training.

]]> Brendan Humphries et al. Influences of Load Carriage and Fatigue on Lower Extremity Kinetics During Walking http://works.bepress.com/eric_dugan/18 http://works.bepress.com/eric_dugan/18 Wed, 30 Nov 2011 12:46:01 PST He Wang et al. The Effects of Repetitive Drop Jumps on Impact Phase Joint Kinematics and Kinetics http://works.bepress.com/eric_dugan/17 http://works.bepress.com/eric_dugan/17 Tue, 05 Jul 2011 14:54:43 PDT The purpose of the study was to investigate the effects of fatigue on lower extremity joint kinematics, and kinetics during repetitive drop jumps. Twelve recreationally active males (n = 6) and females (n = 6) (nine used for analysis) performed repetitive drop jumps until they could no longer reach 80% of their initial drop jump height. Kinematic and kinetic variables were assessed during the impact phase (100 ms) of all jumps. Fatigued landings were performed with increased knee extension, and ankle plantar flexion at initial contact, as well as increased ankle range of motion during the impact phase. Fatigue also resulted in increased peak ankle power absorption and increased energy absorption at the ankle. This was accompanied by an approximately equal reduction in energy absorption at the knee. While the knee extensors were the muscle group primarily responsible for absorbing the impact, individuals compensated for increased knee extension when fatigued by an increased use of the ankle plantar flexors to help absorb the forces during impact. Thus, as fatigue set in and individuals landed with more extended lower extremities, they adopted a landing strategy that shifted a greater burden to the ankle for absorbing the kinetic energy of the impact.

]]> Joshua T. Weinhandl et al. The Effects of Whole Body Vibration on Bone Mineral Density for a Person With a Spinal Cord Injury: A Case Study http://works.bepress.com/eric_dugan/14 http://works.bepress.com/eric_dugan/14 Wed, 19 Jan 2011 09:18:30 PST Bone mineral density (BMD) loss is a medical concern for individuals with spinal cord injury (SCI). Concerns related to osteoporosis have lead researchers to use various interventions to address BMD loss within this population. Whole body vibration (WBV) has been reported to improve BMD for postmenopausal women and suggested for SCI. The purpose of this case study was to identify the effects of WBV on BMD for an individual with SCI. There were three progressive phases (standing only, partial standing, and combined stand with vibration), each lasting 10 weeks. Using the least significant change calculation, significant positive changes in BMD were reported at the trunk (0.46 g/cm2) and spine (.093 g/cm2) for phase 3 only. Increases in leg lean tissue mass and reduction in total body fat were noted in all three phases.

]]> Ronald Davis et al. Muscular Fatigue Increases Ground Reaction Loading Rate During Walking http://works.bepress.com/eric_dugan/11 http://works.bepress.com/eric_dugan/11 Fri, 04 Jun 2010 15:27:30 PDT He Wang et al. Balance, confidence in balance and quality of life in persons with chronic stroke after body weight supported treadmill training http://works.bepress.com/eric_dugan/10 http://works.bepress.com/eric_dugan/10 Mon, 08 Mar 2010 12:21:41 PST Stephanie Combs et al. The effect of body weight support treadmill training on paretic leg contribution in hemiparetic walking in persons with chronic stroke http://works.bepress.com/eric_dugan/7 http://works.bepress.com/eric_dugan/7 Wed, 02 Sep 2009 15:43:09 PDT Elicia Ozimek et al. Stand to sit movement after bi-compartmental knee replacement http://works.bepress.com/eric_dugan/6 http://works.bepress.com/eric_dugan/6 Wed, 02 Sep 2009 15:40:09 PDT He Wang et al. Muscular Fitness http://works.bepress.com/eric_dugan/5 http://works.bepress.com/eric_dugan/5 Wed, 02 Sep 2009 15:34:24 PDT Brendan Humphries et al. Gait Analysis After Bicompartmental Knee Replacement http://works.bepress.com/eric_dugan/4 http://works.bepress.com/eric_dugan/4 Wed, 02 Sep 2009 15:25:12 PDT Background

It is reported that a majority of the patients with knee osteoarthritis have cartilage degeneration in medial and patellofemoral compartments. A bi-compartmental knee replacement system was designed to treat osteoarthritis at medial and patellofemoral compartments. To date, there is very little information regarding the knee mechanics during gait after bi-compartmental knee replacement. The purpose of the study was to evaluate knee strength and mechanics during level walking after knee replacement.

Methods

Ten healthy control subjects and eight patients with unilateral bi-compartmental knee replacement participated in the study. Maximal isokinetic concentric knee extension strength was evaluated. 3D kinematic and kinetic analyses were conducted for level walking. Paired Student t-test was used to determine difference between surgical and non-involved limbs. One way MANOVA was used to determine difference between surgical and control groups.

Findings

The surgical knee exhibited less peak torque and initial abduction moment than both the non-involved and control limbs (P < 0.05). The non-involved limb had less knee extension at stance and greater knee extensor moment during push-off than both the surgical and control limbs (P < 0.05). No differences were found for other typical knee mechanics among the surgical, non-involved, and control limbs during walking (P > 0.05).

Interpretations

Patients with bi-compartmental knee replacement exhibited good frontal plane knee mechanics and were able to produce the same level of knee extensor moment as healthy control limbs during walking. While showing some compensatory patterns during walking, patients with bi-compartmental knee replacement largely exhibited normal gait patterns and knee mechanics.

]]> He Wang et al. Comparing the Effects of Various Whole-Body Vibration Accelerations on Counter-Movement Jump Performance http://works.bepress.com/eric_dugan/1 http://works.bepress.com/eric_dugan/1 Sun, 16 Aug 2009 15:55:02 PDT While it seems that whole body vibration (WBV) might be an effective modality to enhance physical performance, the proper prescription of WBV for performance enhancement remains unknown. The purpose of this study was to compare the immediate effect of various WBV accelerations on counter movement jump (CMJ) height, the duration of any effect, and differences between men and women. Forty-four participants (33 men, 11 women) participated in no less than four CMJ familiarization sessions and completed all vibration sessions. Participants performed a pre-test (three maximal CMJs), followed randomly by one of five WBV accelerations; 1g (no-WBV control), 2.16g, 2.80g, 4.87g, and 5.83g. Participants performed three maximal CMJs immediately, five, and 10 minutes following each 45 sec WBV session. The mean of the three performances was used and calculated as a percentage of the pre-vibration mean value. A Repeated Measures Analysis of Variance (ANOVA; acceleration x time x gender) model was used to analyze the data. The two-way interactions of acceleration-gender (p = 0.033) and time-gender (p = 0.050) were significant. Women performed significantly better following the 2.80g (p = 0.0064) and 5.83g (p = 0. 0125) WBV sessions compared to the 1g (control) session. Men, however, did not experience performance enhancing effects following any of the vibration sessions. While significant differences did not occur between time in either gender, the effects of the 45 sec WBV session in women were transient, lasting approximately five minutes. During the prescription of WBV, gender should be considered given that the results of this study seem to indicate that men and women respond differently to WBV. The results of this study suggest that WBV might be a useful modality as applied during the pre-competition warm-up.

]]> David M. Bazett-Jones et al.