COMPARISON OF TWO METHODS OF MANUAL DIGITIZATION ON ACCURACY AND TIME OF COMPLETION

The purpose of this study was to compare the accuracy and time efficacy of two methods of manual digitization (frame by frame, FXF and points over frame, POF). Two groups (experienced, N=20 and inexperience, N= 20) digitized markers using the FXF and POF method. The markers were digitized automatically using software HUMAN and the coordinates from the automatic digitizing were the true values and the manually digitized values were the measured values. These coordinates were used to compute an average root mean square (RMS) value for each subject. An ANOVA (Group x Method) was used to analyze the difference between digitizing time and RMS values. The POF method was more accurate than the FXF method in all of the landmarks analyzed. The advantage of the POF method lies in the ability of the subjects to continuously track the same point throughout the trial

Effects of physical training on proprioception in older women

Older adulthood is accompanied by declines in muscular strength, coordination, function, and increased risk of falling. Resistance training increases muscular strength in this population but its effect on proprioception is unknown. To evaluate the effect of resistance training on proprioception, community dwelling older women completed a three-month exercise study. A resistance training (RT) group (N=19) underwent supervised weight training three times per week while a non-strength trained control (NSTC) group (N=19) performed range-of-motion activities that mimicked the movements of the RT group without the benefit of muscle loading. Subjects were evaluated at baseline, 6, and 12 weeks for strength and proprioception. Muscular strength was assessed by measuring the subject’s one repetition maximum performance on four different exercises. Static proprioception was measured by the subject’s ability to reproduce a target knee joint angle while dynamic proprioception was measured by the subject’s ability to detect passive knee motion. The RT group made significant strength improvements compared to the NSTC group. Proprioception significantly improved in both groups by 6 weeks. Our findings suggest that improvements in proprioception can be obtained via regular activity that is independent of heavy muscle loading

ENERGY RETURN OF DIFFERENT DESIGNS OF TRACK SPIKES

INTRODUCTION: Advances in technology and design have generated changes to the traditional track spike. Today, there are a number of different spike shapes, the four most common being needle, pyramid, post, and Christmas tree and modified Christmas tree (the last two are also referred to as “compression tier”) (see Figure 1). Running magazines, product advertisements, coaches, and manufacturers make claims about the potential effects of each type of spike design and their use in different situations. To our knowledge, these types of claims and other information regarding spikes or track surfaces, have not been tested and reported in the peer-reviewed literature. METHODS: The purpose of this preliminary study was to examine whether different shaped spikes elicit quantifiable differences in energy return on a Mondo track surface, the most commonly used at track venues. Five different shaped spikes all 7mm in length were used in this study (see Figure #1). The spikes chosen are those commonly used by athletes on various indoor and outdoor track surfaces. The load-deformation between the spikes the track was measured using a Bose Electroforce 3200 (Eden Praire, MN) testing device. OneWay ANOVAs using Sigma Plot 10.5 (Systat Inc., Richmond, CA) were performed to test for significant differences between spikes. Tukey post-hoc comparisons were performed at the p=0.05 level. RESULTS: Figure 2 shows the ANOVA results [F (4,49)=54.78, p<.001] and Tukey post-hoc comparison for the energy returned. The MTREE spike generated the greatest amount of energy returned and was significantly different from the other spikes (p<=0.05). The PYRA spike generated second largest amount of energy returned and was significant different from the PIN and POST spikes. The PIN or needle spike, as expected, had the least amount of energy returned. All spikes penetrated the track surface. DISCUSSION: The notion that compression spikes have less track penetration is unfounded. All the spikes tested penetrated the track under loads less than 105 N. Considering that vertical ground reaction force (GRF) increases linearly during walking and running from 1.2 BW to approximately 2.5 BW at 6.0 m s−1 and remains constant during forward lean sprinting at higher speeds, the likehood of any of the tested spikes not penetrating the Mondo track surface seems improbable (Keller et al., 1996). For the Mondo track the spike with the largest energy return was the MTREE design. This MTREE provided the largest spike surface area, which helped it to compress the track. The common PIN design provided the least energy return but absorbed the least amount of energy. All the compression spikes seem to provide larger amounts of energy return when compared to the PIN. The measured energy returned by the various spikes is relatively small (N*mm). However, for this study, the energy return was determined for only one spike while most sprint shoes have a sole plate with up to 10 mounted spikes. While it is difficult to assess how much of the energy returned in the spike-track surface interaction might actually aid the sprinter, these findings are nevertheless noteworthy. It is not uncommon for results in sprint races to be separated by only thousandths of a second, where even small levels of energy return could potentially make the difference between winning or losing a race. CONCLUSION: This study shows that spike design affects the amount of energy returned and absorbed by a Mondo track surface. While all of the spikes tested penetrated the track surface, the modified Christmas tree design returned the most energy on the Mondo surface. Knowledge of which spike design offers the highest energy return on the various track surfaces that athletes compete on could be useful to coaches and athletes, as well as, spike and track manufacturers and thus is worthy of further investigation

Proprioception, gait kinematics, and rate of loading during walking: Are they related?

The cyclic nature of walking can lead to repetitive stress and associated complications due to the rate of loading (ROL) experienced by the body at the initial contact of the foot with the ground. An individual’s gait kinematics at initial contact have been suggested to give rise to the ROL, and a repetitive, high ROL may lead to several disorders, including osteoarthritis. Additionally, proprioception, the feedback signaling of limb position and movement, may play a role in how the foot strikes the ground and thus, the ROL. Our goal was to explore the relationship between proprioception, gait kinematics and ROL. Thirty-eight women were recruited for gait analysis, and the gait characteristics 50ms prior to and at initial contact were examined. Two proprioception tests, joint angle reproduction and threshold to detect passive motion were used to examine the subject’s proprioceptive acuity. Our results indicate that individuals with a larger knee angle (i.e., greater extension) 50ms prior to initial contact (IC) experience a higher ROL during gait and have poorer proprioceptive scores. However, it remains unclear whether poor proprioception causes a high ROL or if a high ROL damages the mechanoreceptors involved in proprioception, but the apparent relationship is significant and warrants further investigation

Does Vibration Training Improve Physical Function and Quality of Life in Fibromyalgia Syndrome?

poster abstractExercise and physical activity recommendations are an integral component of the overall management of fibromyalgia. Unfortunately, despite the known health, fitness, and symptom relief benefits, underlying pain and fatigue prevent most from initiating (or maintaining) physical activity and exercise programs, thereby contributing to sedentary lifestyles that lead to low levels of aerobic and muscular fitness. Therefore, it is important to identify alternative approaches to exercise programming in the overall management of fibromyalgia. Vibration training is a relatively new approach to exercise that has been shown to elicit numerous benefits; however little is known about the effects of this training method in fibromyalgia. Therefore, the primary aim of this study is to evaluate the effects of vibration training in improving musculoskeletal function, balance and postural control, and health-related quality of life in patients diagnosed with fibromyalgia

On-Line Quizzing and Its Effect on Student Engagement and Academic Performance

The goal of this study was to determine if on-line out-of-class quizzing would lead to increases in (a) classroom engagement (b) academic performance and (c) preparation perception of college students. Twenty-four sophomore level students enrolled in a required functional anatomy course participated in this study. Results from this study indicate that on-line quizzing had a statistically significant impact on some indicators of student classroom engagement. However, on-line quizzing had no statistically significant impact on academic performance as evidenced by test scores. Finally, student perceptions, as a result of on-line quizzing significantly improved