pedal mechanics

BACKGROUND: During and after exercise, dynamic 31 P MR parameters are typically measured using an MR-compatible ergometer. Self-built equipment for local condition can be constructed where possible. PURPOSE: To develop a pedal resistance ergometer with rocker arm based on a system that combines electric weight displacement, visual self-monitoring, and exercise triggering. The repeatability and reproducibility were tested. METHODS: The hardware and software for the ergometer were constructed from commercial components in a home laboratory...

Every animal secretes mucus, placing them among the most diverse biological materials. Mucus hydrogels are complex mixtures of water, ions, carbohydrates, and proteins. Uncertainty surrounding their composition and how interactions between components contribute to mucus function complicates efforts to exploit their properties. There is substantial interest in commercializing mucus from the garden snail, Cornu aspersum, for skincare, drug delivery, tissue engineering, and composite materials. C. aspersum secretes three mucus-one shielding the animal from environmental threats, one adhesive mucus from the pedal surface of the foot, and another pedal mucus that is lubricating...

Crank power is produced by extension and flexion of the hip and knee joints during steady-state pedaling below 120 rpm. Despite the pedaling cadence exceeding 120 rpm during track cycling, the power production strategy for lower-limb coordination above 120 rpm is unknown. This study aimed to assess the effects of various pedaling cadences on the power production strategy of lower-limb coordination during steady-state pedaling. Twenty trained collegiate cyclists performed a 30-s steady-state pedaling exercise at 50% of maximal anaerobic power under four different conditions with 90-, 120-, 150- and 180-rpm pedaling cadences...

OBJECTIVES: To quantify the acute effects of graded blood flow restriction on the interaction between changes in mechanical output, muscle oxygenation trends and perceptual responses to heart rate clamped cycling. DESIGN: Repeated measures. METHODS: Twenty-five adults (21 men) performed six, 6-min cycling bouts (24 min of recovery) at a clamped heart rate corresponding to their first ventilatory threshold at 0 % (unrestricted), 15 %, 30 %, 45 %, 60 % and 75 % of arterial occlusion pressure with the cuffs inflated bilaterally from the fourth to the sixth minute...

Facing an unrelenting rise in dementia cases worldwide, researchers are exploring non-pharmacological ways to ameliorate cognitive decline in later life. Twenty older adults completed assessments before and after a single bout of interactive physical and cognitive exercise, by playing a neuro-exergame that required pedaling and steering to control progress in a tablet-based video game tailored to impact executive function (the interactive Physical and Cognitive Exercise System; iPACES v2). This study explored the cognitive and biomarker outcomes for participants with mild cognitive impairment (MCI) and normative older adults after 20 min of pedal-to-play exercise...

Whilst people typically chose to locomote in most economical fashion, during bicycling they will, unusually, chose cadences that are higher than metabolically optimal. Empirical measurements of the intrinsic contractile properties of the vastus lateralis (VL) muscle during submaximal cycling suggest that the cadences that people self-selected (SSC) might allow for optimal muscle fascicle shortening velocity for the production of knee extensor muscle power. It remains unclear, however, whether this is consistent across different power outputs where the SSC varies...

During the field operation of rice combine harvester, the vibration generated by vibration component will only reduce mechanical reliability and yield, but also cause resonance in the human body, leading to a decrease in driving comfort and even damage to the driver's health. To study the impact of combine harvester vibration on driving comfort, a certain type of tracked rice combine harvester was selected as the research object, and vibration tests were carried out based on vibration source analysis in the driving cab during field harvesting operations...

Diabetes is a fast-growing chronic metabolic disorder that is widely associated with foot ulcers. The major challenge among these ulcers is wound infections, altered inflammatory responses, and a lack of angiogenesis that can complicate limb amputation. The foot, because of its architecture, becomes the part most prone to complications and the infection rate is higher mainly between the toes due to the humid nature. Therefore, the infection rate is significantly higher. Wound healing in diabetes is a dynamic process usually delayed due to poor immune function...

Background: The prominent insertion/deletion polymorphism in the gene for the major modulator of tissue perfusion, angiotensin-converting enzyme ( ACE-I/D ) is associated with variability in adjustments in cardiac and skeletal muscle performance with standard forms of endurance and strength type training. Here, we tested whether the ACE-I/D genotype would be associated with variability in the effects of interval-type training on peak and aerobic performance of peripheral muscle and cardio-vasculature and post-exercise recovery...

Potassium feldspar (K2 O·Al2 O3 ·6SiO2 ) is considered to be the most important source of potash fertilizer. The use of microorganisms to dissolve potassium feldspar is a low-cost and environmentally friendly method. Priestia aryabhattai SK1-7 is a strain with a strong ability to dissolve potassium feldspar; it showed a faster pH drop and produced more acid in the medium with potassium feldspar as the insoluble potassium source than in the medium with K2 HPO4 as the soluble potassium source. We speculated whether the cause of acid production was related to one or more stresses, such as mineral-induced generation of reactive oxygen species (ROS), the presence of aluminum in potassium feldspar, and cell membrane damage due to friction between SK1-7 and potassium feldspar, and analyzed it by transcriptome...

OBJECTIVES:  The aim of this study was to define landmarks of the intermetatarsal channel of the dorsal pedal artery and to assess whether damage to the dorsal pedal artery during metatarsal screw placement in dogs undergoing pan- and partial-tarsal arthrodesis (PanTA/ParTA) could be a mechanism in the development of plantar necrosis. STUDY DESIGN:  This study was divided in to two parts: (1) ex-vivo anatomical study: 19 canine cadavers, (2) retrospective clinical study: 39 dogs...

The present study aimed to investigate whether a 2-week arm cycling sprint interval training (SIT) program modulated corticospinal pathway excitability in healthy, neurologically intact participants. We employed a pre-post study design with two groups: 1) an experimental SIT group and 2) a non-exercising control group. Transcranial magnetic stimulation (TMS) of the motor cortex and transmastoid electrical stimulation (TMES) of corticospinal axons were used at baseline and post-training to provide indices of corticospinal and spinal excitability, respectively...

An important cognitive requirement in multitasking is the decision of how multiple tasks should be temporally scheduled (task order control). Specifically, task order switches (vs. repetitions) yield performance costs (i.e., task-order switch costs), suggesting that task order scheduling is a vital part of configuring a task set. Recently, it has been shown that this process takes specific task-related characteristics into account: task order switches were easier when switching to a preferred (vs. non-preferred) task order...

The therapeutic efficacy of mirror visual feedback (MVF) is attributed to the perception of embodiment. This study intends to investigate the instantaneous effect of embodiment on brain connectivity. Twelve healthy subjects were required to clench and open their non-dominant hands and keep the dominant hands still during two experimental sessions. In the first session, the dominant hand was covered and no MVF was applied, named the sham-MVF condition. Random vibrotactile stimulations were applied to the non-dominant hand with MVF in the subsequent session...

Purpose: This study aimed to investigate muscle damage when performing equal mechanical work of fast and slow pedaling speed by eccentric muscle actions (ECCs) cycling. Methods: Nineteen young men [mean ± standard deviation (SD) age: 21.0 ± 2.2 years; height: 172.7 ± 5.9 cm; and body mass: 70.2 ± 10.5 kg] performed maximal effort of ECCs cycling exercise with fast speed (Fast) and slow speed trials (Slow). First, subjects performed the Fast for 5 min by one leg. Second, Slow performed until the total mechanical work was equal to that generated during Fast other one leg...

Deep venous thrombosis might present in an acute condition requiring early thrombus removal. Several endovascular and surgical approaches are available with a short treatment time and minimal complications compared to pharmacotherapies. However, due to a lack of evidence, these are not the first treatment choice for deep vein thrombosis. Our case report showed a successful multimodality treatment for an acute-on-chronic massive deep vein thrombosis from the inferior vena cava to the pedal vein. A 47-year-old with chief complaints of cold, significant swelling, and severe pain in her left leg was diagnosed with deep vein thrombosis through Doppler ultrasound and contrast-enhanced computed tomography...

In a prospective, randomized, experimental non-blinded study, the continuous infusions rates of propofol required to prevent swallowing (P-SR) or pedal withdrawal reflex (P-WR) were evaluated in healthy premedicated dogs. Dogs were randomly assigned to one of two treatments at weekly intervals. Following premedication with a combination of acepromazine and methadone, anesthesia was induced with propofol (4.00 mg kg-1 per min) and was maintained for 90 min. The propofol infusion rate was increased or decreased by 0...

Dynamic loads have short and long-term effects in the rehabilitation of lower limb joints. However, an effective exercise program for lower limb rehabilitation has been debated for a long time. Cycling ergometers were instrumented and used as a tool to mechanically load the lower limbs and track the joint mechano-physiological response in rehabilitation programs. Current cycling ergometers apply symmetrical loading to the limbs, which may not reflect the actual load-bearing capacity of each limb, as in Parkinson's and Multiple Sclerosis diseases...

INTRODUCTION: Attention-Deficit/Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder for which behavioural treatments such as exercise are recommended as part of a multi-disciplinary treatment program. Exercise improves executive function in individuals with ADHD, but limited information exists regarding the mechanisms involved in the response. We examined task-evoked brain responses during exercise and seated rest in 38 adolescents (n = 15 ADHD; age = 13.6+/-1.9, male = 73...

The photoisomerization of chromophores embedded in biological environments is of high importance for biomedical applications, but it is still challenging to define the photoisomerization mechanism both experimentally and computationally. We present here a computational study of the azobenzene molecule embedded in a DPPC lipid membrane, and assess the photoisomerization mechanism by means of the quantum mechanics/molecular mechanics surface hopping (QM/MM-SH) method. We observe that while the trans -to- cis isomerization is a slow process governed by a torsional mechanism due to the strong interaction with the environment, the cis -to- trans mechanism is completed in sub-ps time scale and is governed by a pedal-like mechanism in which both weaker interactions with the environment and a different geometry of the potential energy surface play a key role...