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Dive into the research topics where Michael Laymon is active.

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Featured researches published by Michael Laymon.


Journal of Visualized Experiments | 2012

The Use of Thermal Infra-Red Imaging to Detect Delayed Onset Muscle Soreness

Hani H. Al-Nakhli; Jerrold Petrofsky; Michael Laymon; Lee Berk

Delayed onset muscle soreness (DOMS), also known as exercise induced muscle damage (EIMD), is commonly experienced in individuals who have been physically inactive for prolonged periods of time, and begin with an unexpected bout of exercise, but can also occur in athletes who exercise beyond their normal limits of training. The symptoms associated with this painful phenomenon can range from slight muscle tenderness, to severe debilitating pain. The intensity of these symptoms and the related discomfort increases within the first 24 hours following the termination of the exercise, and peaks between 24 to 72 hours post exercise. For this reason, DOMS is one of the most common recurrent forms of sports injury that can affect an individuals performance, and become intimidating for many. For the last 3 decades, the DOMS phenomenon has gained a considerable amount of interest amongst researchers and specialists in exercise physiology, sports, and rehabilitation fields. There has been a variety of published studies investigating this painful occurrence in regards to its underlying mechanisms, treatment interventions, and preventive strategies. However, it is evident from the literature that DOMS is not an easy pathology to quantify, as there is a wide amount of variability between the measurement tools and methods used to quantify this condition. It is obvious that no agreement has been made on one best evaluation measure for DOMS, which makes it difficult to verify whether a specific intervention really helps in decreasing the symptoms associated with this type of soreness or not. Thus, DOMS can be seen as somewhat ambiguous, because many studies depend on measuring soreness using a visual analog scale (VAS), which is a subjective rather than an objective measure. Even though needle biopsies of the muscle, and blood levels of myofibre proteins might be considered a gold standard to some, large variations in some of these blood proteins have been documented, in addition to the high risks sometimes associated with invasive techniques. Therefore, in the current investigation, we tested a thermal infra-red (IR) imaging technique of the skin above the exercised muscle to detect the associated muscle soreness. Infra-red thermography has been used, and found to be successful in detecting different types of diseases and infections since the 1950s. But surprisingly, near to nothing has been done on DOMS and changes in skin temperature. The main purpose of this investigation was to examine changes in DOMS using this safe and non-invasive technique.


European Journal of Applied Physiology | 2000

The relationship between exercise work intervals and duration of exercise on lower extremity training induced by electrical stimulation in humans with spinal cord injuries.

Jerrold Petrofsky; Ralph Stacy; Michael Laymon

Abstract A group of 90 male paraplegics were studied to determine the optimal training protocol for isokinetic exercise induced by functional electrical stimulation of the quadriceps muscles. The parameters that were varied were the number of training sessions a week, the length of the training sessions each day, and the work-rest intervals in each training session. Training for 3 days a week for 30 min a day with 6 s of exercise and 6 s of rest proved the optimal protocol. Training for 5 days or for 1 day a week was not as effective in training strength or endurance. A combination of 50% work and 50% rest produced a much greater gain in strength and endurance than work:rest ratios of 66%:33% or 25%:75%. When training was conducted for 5 min, 15 min or 30 min each day, the greatest increase was found when the muscles were exercised for 30 min each day. While more variables need to be examined, this study has provided some initial guidelines for isokinetic training of humans using electrical stimulation.


Medical Science Monitor | 2013

Effect of heat and cold on tendon flexibility and force to flex the human knee

Jerrold Petrofsky; Michael Laymon; Haneul Lee

Background It is commonly believed in medicine that using heat will increase the distensability and flexibility of soft tissue. If true, increased flexibility would be a positive factor to reduce injuries in sports. However, cold should have the opposite effect and is often used to treat sports injuries. This study was accomplished to quantify the effect of heat and cold on the force needed to flex the knee and laxness of the anterior and posterior cruciate ligaments. Material/Methods The present study examined 20 male and female subjects to determine if heat would increase extensibility of the anterior and posterior cruciate ligaments of the knee and reduce the force needed to flex the knee. Cold exposure was examined to see if it would have the opposite effect. There were 4 experiments in the series: The first was a room temperature series; the second was a series where cold was applied with an ice pack for 20 minutes; in the third, hydrocollator heat packs were applied for 20 minutes; and in the fourth, ThermaCare heat wraps were applied for 4 hours on the quadriceps and knee. Tendon extensibility was measured with a KT2000. The force for flexing the knee was measured by passive movement being applied (CPM) to the knee through 30° and the force required to move the leg was measured. Results The results show that the anterior and posterior cruciate ligament flexibility increased and the force needed to move the knee decreased with heat by about 25% compared to cold application. Conclusions Heat is beneficial in increasing muscle and ligament flexibility and may help reduce athletic injuries, but cold treatment may have the opposite effect.


Medical Science Monitor | 2013

Postural sway and Rhythmic Electroencephalography analysis of cortical activation during eight balance training tasks

Yuen Yi F. Tse; Jerrold Petrofsky; Lee Berk; Noha Daher; Everett Lohman; Michael Laymon; Paula Cavalcanti

Background The purpose of this study was to investigate the changes in the Power Spectrum Density (PSD) of the electroencephalography (EEG) in common sensorimotor balance training tasks of varying difficulty. Sensorimotor balance exercises including alteration of vision, base of support or surface compliance are used to improve postural control. These exercises are presumed to induce supraspinal adaptation, however, there were no studies that investigated the power changes of the cortical activity in these static balance tasks. Our objective was to provide evidence in the cortical involvement with the static balance tasks frequently used in sensorimotor training. Material/Methods Postural sway and EEG changes of alpha, beta and sigma wave bands were measured in seventeen participants during eight balance tasks of varying difficulty with eyes open and closed, feet in tandem or apart and on foam or a firm surface. Results The power of beta and sigma bands increased significantly at the parietal and central area of the brain in tasks with eyes open together with one sensory factor (base of support or surface compliance) or two sensory factors (base of support and surface compliance) altered, and in task with three sensory factors (vision, base of support and surface compliance) altered from the control task. Conclusions This study demonstrated the cortical involvement in the sensorimotor balance tasks, suggesting that these exercises may induce cortical adaptation for postural control. The results support subcortical control with increased task difficulty and the increase in cortical processing when task became extremely challenging.


Diabetes Technology & Therapeutics | 2012

The use of thermal infrared imaging to assess the efficacy of a therapeutic exercise program in individuals with diabetes.

Hani H. Al-Nakhli; Jerrold Petrofsky; Michael Laymon; Daisuke Arai; Kelli Holland; Lee Berk

BACKGROUND Exercise is of great value for individuals with diabetes in helping to control their hemoglobin A1c levels and in increasing their insulin sensitivity. Delayed-onset muscle soreness (DOMS) is a common problem in healthy individuals and in people who have diabetes. People with diabetes are also faced with metabolic and endothelial impairments, which could make DOMS even worse. But because they usually have neuropathies, they may not feel this soreness appropriately, leading to premature return to exercise and causing further injuries. RESEARCH DESIGN One hundred eighteen subjects participated in this study and were divided into four groups. Two groups (healthy and diabetes) performed a series of abdominal exercises, and the other two groups (healthy and diabetes) performed a series of arm exercises to induce DOMS. Skin temperature above the muscle was assessed using a thermal infrared camera, and perceived soreness of the exercised muscle was assessed using a 100-mm visual analog scale. Serum myoglobin concentrations were also measured. RESULTS There was a significant increase in skin temperature 24 h post-exercise for all four exercise groups (P<0.05), where the combined average increase in skin temperature for all four groups was approximately 0.65°C from baseline. Also, 24 h post-exercise, all four groups were significantly sorer than they were at baseline (P<0.05). Serum myoglobin levels were also significantly higher on day 3 compared with day 1 (P<0.05). CONCLUSION Infrared thermal imaging may be a valuable technique of seeing which muscles are sore hours or even days after the exercise is over. Thus, thermal imaging would be an efficient and painless way of looking at DOMS in both healthy individuals and individuals who have diabetes, even if they are facing neurological problems.


Journal of Clinical Densitometry | 2002

A Study on the Influence of Calcified Intervertebral Disk and Aorta in Determining Bone Mineral Density

David D. Cherney; Michael Laymon; Amy McNitt; Steve Yuly

This study utilized dual-energy X-ray absorptiometry (DXA) to determine the association that age-related calcinosis of the aorta and intervertebral disks have in determining bone mineral density (BMD). Eight cadavers were chosen at random and were scanned with DXA before and after the removal of the aorta and intervertebral disks. Our results showed that the removal of sclerotic aortas decreased the vertebral BMD an average of 4.64% and the removal of two lumbar intervertebral disks further decreased BMD an average of 11.93%. These results were deemed significant at the 0.01 level using a Friedman two-way analysis of variance by ranks. It can be concluded that the presence of aortic arteriosclerotic lesions and intervertebral disk chondrocalcinosis add a significant contribution to BMD.


Medical Science Monitor | 2015

Effect of Heat, Cold, and Pressure on the Transverse Carpal Ligament and Median Nerve: A Pilot Study

Michael Laymon; Jerrold S. Petrofsky; James M. McKivigan; Haneul Lee; Jongeun Yim

Background This study quantified the effects of heat, cold, and pressure on the median nerve and transverse carpal ligament in subjects without carpal tunnel syndrome. Material/Methods Subjects were individuals ages 20–50 who had no symptoms of carpal tunnel disease. Imaging ultrasound was used to measure the clearance around the median nerve, transverse ligament elasticity, nerve conduction velocity, thickness of the carpal ligament, and area of the median nerve. Pressure was applied to the carpal ligament to assess the effects of increasing pressure on these structures. On 3 separate days, 10 subjects had ThermaCare heat or cold packs applied, for either 60 or 120 minutes for heat or 20 minutes for cold, to the palmer surface of the hand. Results Tissue changes were recorded as a response to pressure applied at 0, 5, 10, and 20 N. The size of the nerve and ligaments were not significantly altered by pressure with the hand at room temperature and after cold exposure. After heat, the nerve, ligaments, and tendons showed significantly more elasticity. Conclusions Application of cold to the hand may reduce compression of the carpal ligament and nerve.


Medical Science Monitor | 2013

CoQ10 and Endothelial Function in Asians from Korea compared to Asians born in the United States and US Born Caucasians

Jerrold Petrofsky; Michael Laymon; Haneul Lee; Jong Yim; Erin Harnandez; Donny Dequine; Lindsay Thorsen; Kennith Lovell; Joshua Andrade

Background The vascular endothelium is the interface between the blood and vascular smooth muscle in arteries. It is easily damaged by oxidative stress. Recent studies show that Asians are more susceptible than Caucasians to impairment of endothelial function. This study examined endothelial function in US-born Caucasians, Asians from Korea, and US-born Asians (almost all Korean decent) and examined the effect of coenzyme Q10 (CoQ10) on endothelial function. Material/Methods Twenty Caucasians and 30 Asians participated (<35 years old, males and females). Endothelial function was assessed by the skin blood flow response to local heat using a thermode for 6 minutes at 44°C and by vascular occlusion for 4 minutes followed by release and measurement of skin blood flow for 2 minutes. In the US-born subjects, the experiments were repeated after 2-week administration of CoQ10 or a placebo. Results When applying 6 minutes of local heat at 44°C, the skin blood flows were significantly higher in Caucasians than both Asian groups Asians. Likewise after vascular occlusion, the blood flow response was greater in Caucasians compared to Asians. Asians born in Asia had the lowest response of the 3 groups of subjects. Administering CoQ10 for 2 weeks eliminated much of the difference between the groups, whereas there was no difference with a placebo. Conclusions These findings suggest that Asians either born in Asia or the US may have lower endothelial function than Caucasians. This may be explained, in part, by genetic variations causing increased oxidative stress from westernized diets in Asians. Co enzyme Q10 administration narrows the difference between the groups.


Journal of Strength and Conditioning Research | 2016

Use of Low Level of Continuous Heat as an Adjunct to Physical Therapy Improves Knee Pain Recovery and the Compliance for Home Exercise in Patients With Chronic Knee Pain: A Randomized Controlled Trial

Jerrold S. Petrofsky; Michael Laymon; Faris S. Alshammari; Haneul Lee

Abstract Petrofsky, JS, Laymon, MS, Alshammari, FS, and Lee, H. Use of low level of continuous heat as an adjunct to physical therapy improves knee pain recovery and the compliance for home exercise in patients with chronic knee pain: a randomized controlled trial. J Strength Cond Res 30(11): 3107–3115, 2016—This study examined if the use of low level continuous heat (LLCH) wraps at home between physical therapy sessions at a clinic resulted in better therapy outcomes in patients with chronic knee pain. Fifty individuals with chronic nonspecific knee pain was randomly allocated to 2 groups: the LLCH group and the placebo group. All subjects underwent 1 hour of conventional physical therapy twice per week for 2 weeks at the outpatient clinic and they were asked to accomplish 1 hour of therapeutic exercise at home each day between sessions. The LLCH group applied LLCH knee wraps for 6 hours at home before home exercise while placebo group took a placebo ibuprofen. (This was done since placebo heat is impossible to use since subjects would notice that the wraps were cold) Before, during, and after intervention, pain intensity, active range of motion of the knee (AROM), knee strength, and home exercise compliance were measured. The LLCH group showed pain attenuation after 2 weeks of therapy sessions (p ⩽ 0.05). AROM and strength of the knee significantly improved over time compared to the placebo group. Home exercise compliance was significantly higher in the LLCH group than placebo group (p ⩽ 0.05). These results indicated that the use of LLCH as an adjunct to conventional physical therapy for chronic knee pain significantly improved pain attenuation and recovery of strength and movement in patients with chronic knee pain.


European Journal of Applied Physiology | 2000

Blood pressure and heart rate responses during a fatiguing isometric exercise in paraplegic men with hypertension

Jerrold Petrofsky; Michael Laymon

Abstract A group of 45 male subjects were examined in a cross-sectional study to compare the blood pressure response that occurs during isometric exercise maintained to fatigue among control subjects and paraplegic patients with (PH) and without essential hypertension (PN). Two muscle groups were examined: the handgrip muscles (voluntary effort) and the quadriceps muscles. The tension chosen for the contraction was 40% of the muscles maximum strength for both muscle groups. While the paraplegic groups had more strength in their handgrip muscles than that found for the controls, the control subjects had more strength in their quadriceps muscles than either of the paraplegic groups. During the fatiguing isometric contractions, the rate of rise and absolute systolic blood pressure was higher in the PH than the other groups of subjects. The diastolic pressure of the PH group, while elevated during exercise, was only elevated to the same degree as the increase in resting diastolic pressure above normal. Heart rate changes during exercise was the same in all groups of subjects for handgrip contractions. The controls had the same heart rate response to handgrip as to leg exercise. The paraplegic groups showed no heart rate change during fatiguing contractions of their quadriceps muscles. The PH group actually showed a reduction in heart rate during the leg exercise.

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Iman Akef Khowailed

American Physical Therapy Association

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Lee Berk

Loma Linda University

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Stacy Fisher

Touro University Nevada

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