The aim of the study undertaken was to establish the effect of cooling on fatigue of the skeletal muscle and recovery after undergoing physical load of different modes by humans. Methods: Muscle temperature measuring, electrical stimulation, isometric, isokinetic, eccentric-concentric load, evaluation of creatine kinase, leg immersion in cold water, mathematical ...

Humans run faster by increasing a combination of stride length and stride frequency. In slow and medium-paced running, stride length is increased by exerting larger support forces during ground contact, whereas in fast running and sprinting, stride frequency is increased by swinging the legs more rapidly through the air. Many ...

OBJECTIVEOlder people with type 2 diabetes are at high risk of mobility disability. We investigated the association of diabetes with lower-limb muscle mass and muscle quality to verify whether diabetes-related muscle impairments mediate the association between diabetes and low walking speed.RESEARCH DESIGN AND METHODSWe performed a cross-sectional analysis of 835 ...

Background: Novel powered prosthetic ankles currently incorporate finite state control, using kinematic and kinetic sensors to differentiate stance and swing phases/sub-phases and control joint impedance and position or torque. For more intuitive control, myoelectric control of the ankle using the remnant residual limb dorsiflexors and plantarflexors, perhaps in concert with ...

The functions of the gastrocnemius-soleus (G-S) complex and other plantar flexor muscles are to stabilize and control major bony joints, as well as to provide primary coordination of the foot during the stance phase of gait. Geometric positioning of the foot and transferring of plantar loads can be adversely affected ...

Passive properties of muscles and tendons, including their elasticity, have been suggested to influence motor control. We examine here the potential role of passive elastic muscle properties at the rat ankle joint, focusing on their potential to specify an equilibrium position of the ankle. We measured the position-dependent passive torques ...

The purpose of this study was to determine the long-term impact of surgical repair and subsequent 6-week immobilization of an Achilles tendon rupture on muscle strength, muscle strength endurance and muscle activity. 63 patients participated in this study on average 10.8±3.4 years after surgically repaired Achilles tendon rupture and short-term ...

Picelli A, Bonetti P, Fontana C, Barausse M, Dambruoso F, Gajofatto F, Girardi P, Manca M, Gimigliano R, Smania N. Is spastic muscle echo intensity related to the response to botulinum toxin type A in patients with stroke? A cohort study. OBJECTIVE: To investigate the relationship between gastrocnemius muscle echo ...

PURPOSE: To determine if peroneus longus (PL), peroneus brevis (PB), medial gastrocnemius (MG) and tibialis anterior (TA) muscle activation patterns during inversion perturbation and running tasks are suppressed following lidocaine injection to the anterior talofibular (ATF) and calcaneofibular (CF) ligament regions. METHODS: Fourteen recreationally active male subjects (age, 24.8 ± 2.9 years; height, ...

STUDY DESIGN: Blinded, placebo-controlled, prospective clinical trial. PURPOSE: To examine the effects of botulinum toxin type A (BTX-A) injections into plantar flexor muscles in stroke patients with equinovarus gait. SUBJECTS: 15 post-stroke and 10 matched neurologically intact subjects. METHODS: Modified Ashworth Scale (MAS) and Fugl-Meyer assessment of physical function scale ...

Introduction: Changes occur in muscles and nerves with aging. In this study we explore the relationship between unipedal stance time (UST) and frontal plane hip and ankle sensorimotor function in subjects with diabetic neuropathy. Methods: UST, quantitative measures of frontal plane ankle proprioceptive thresholds, and ankle and hip motor function ...

: The sympathetic innervation of the hand was demonstrated using formaldehyde staining techniques in the 1990s and provides a basis for both medical (botulinum toxin type A) and surgical (sympathectomy) therapeutic approaches. This research investigates the sympathetic innervation of the human foot using tyrosine hydroxylase immunohistochemistry. : With institutional review ...

The present study investigated the effects of somatosensory conditions at the foot and ankle on postural responses to plantar-flexor muscle fatigue during bipedal quiet stance. Twenty-two young healthy adults were asked to stand upright as still as possible with their eyes closed in three somatosensory conditions (normal, altered and improved) ...

Dorsch S, Ada L, Canning CG, Al-Zharani M, Dean C. The strength of the ankle dorsiflexors has a significant contribution to walking speed in people who can walk independently after stroke: an observational study. OBJECTIVE: To investigate the relationship between the strength of muscles of the affected lower limb and ...

In upper limb muscles, altered corticospinal excitability and reduction in neural drive are observed in parallel with peripheral fatigue during prolonged and/or repeated contractions. However, the fatigue-induced adaptations of central and peripheral elements and their relative contribution to lower limb muscle performance are yet to be fully explored. In the ...

The main goal of this study was to study the performance of fuzzy logic controllers combined with simplified hybrid amplitude/pulse-width (AM/PW) modulation to regulate muscle force via nerve electrical stimulation. The recruitment curves with AM/PW and AM modulations were constructed for the calf muscles of rabbits. Integrated with the modulation ...

The stability of the maximal muscle response (M(max)) is critical to H reflex methodology. It has previously been reported that the amplitude of M(max) declines over time. If reproducible, this finding would have implications for all experimental studies that normalise the output of the motoneurone pool against the M wave. ...

The production of graceful skeletal movements requires coordinated activation of multiple muscles that produce torques around multiple joints. The work described herein is focused on one such movement, stance, that requires coordinated activation of extensor muscles acting around the hip, knee and ankle joints. The forces evoked in these muscles ...

ABSTRACT: BACKGROUND: Muscle herniation of the leg is a rare clinical entity. Yet, knowing this condition is necessary to avoid misdiagnosis and delayed treatment. In the extremities, muscle herniation most commonly occurs as a result of an acquired fascial defect, often due to trauma. Different treatment options for symptomatic extremity ...

We present a case of atypical acute limb ischemia in a non-diabetic patient, with ankle-brachial pressure index of 0.6 and rest pain localized exclusively over the gastrocnemius muscle, sparing the foot. This uncommon presentation was attributed to an impaired perigenicular collateral network. Thrombolysis restored adequate perfusion only temporarily and was ...

A novel method of visual stimulus, reported by Kaneko et al. [14], induced a vivid kinesthetic illusion and increased the corticomotor excitability of the finger muscles without any overt movement. To explore the effect of this method on the lower limbs, motor evoked potentials (MEP) were recorded from the left ...

Abstract Large impact loading with abnormal muscle activity and motion patterns may contribute to lower extremity injuries in ballet dancers. Yet, few studies investigated the influence of injury on the ballet movement. The purpose of this study was to find the neuromuscular and biomechanical characteristics in dancers with and without ...

The biological central pattern generator (CPG) integrates open and closed loop control to produce over-ground walking. The goal of this study was to develop a physiologically based algorithm capable of mimicking the biological system to control multiple joints in the lower extremities for producing over-ground walking. The algorithm used state-based ...

The purpose of this study was to investigate the effects of unilateral muscle fatigue induced on the hip flexors/extensors or the ankle plantar/dorsiflexors on unipedal postural stability under different visual conditions. Twenty-four healthy young women completed 2 testing sessions 1 week apart with a randomized order assigned according to the muscles ...

BackgroundMeasurement of muscle hardness is important for objective evaluation of the muscle condition. Muscle hardness may be related to muscle size, but this relationship has not yet been examined.PurposeTo examine the relationship between the size and hardness of the medial gastrocnemius muscle (MG) at different ankle joint angles.Material and MethodsTwelve ...

The aim of this study was to evaluate the changes in electromyographic (EMG) activity of the lower limb muscles, and hip, knee and ankle kinematics during gait while wearing low- (4-cm) and high-heeled (10-cm) shoes in 31 young and 15 middle-aged adult women. We observed an increase in knee flexion ...

BACKGROUND: Hypothyroidism has detrimental effects on reproduction in females of many species. Studies of hypothyroidism in bitches are limited and results conflicting. HYPOTHESIS: Hypothyroidism interferes with reproductive function and health of offspring in bitches. ANIMALS: A total of 9 healthy mixed-breed bitches (control) and 9 mixed breed bitches with hypothyroidism ...

Although track and field spike shoes are crafted for runners, these shoes are not designed for regular walking. With such shoes, runners may eventually encounter serious chronic injuries such as plantar fasciitis, shin splints, achilles tendinitis, chondromalacia, and iliotibial band syndrome. To address this problem, a modified spike shoe was ...

Focal myositis is a rare, benign inflammatory pseudotumor of the skeletal muscle of unknown etiology. In Korea, there is no case report of focal myositis, which is not combined with connective tissue disease. We present an unusual case of focal myositis with ankle contracture, involving more than two muscles. A ...

Muscular variations in the lower extremity are frequently encountered when performing cadaveric dissections. The utility of supernumerary muscles assumes importance in reparative foot surgery. The purpose of the current case study is to report the unilateral presence of double peroneal muscles in the evertors of the foot. The peroneal compartment ...

A 27-year-old woman presented with a 1-year history of progressive weakness and grip myotonia in both hands. There was no family history of any similar condition and no personal history of cataracts. Physical examination revealed weakness of the muscles of the face, neck, shoulder girdle, and hands. Myotonia was elicited ...

Common fibular (peroneal) nerve palsy has many etiologies. A rare cause with a poorly understood pathophysiology is common fibular nerve palsy that follows an ankle injury. Since the original description of this pathologic entity a century ago, several mechanisms have been posited. We present two cases of common fibular nerve ...

Reactions involving thiol biochemistry seem to play a crucial role in skeletal muscle fatigue. N-acetylcysteine amide (NACA) and l-ergothioneine (ERGO) are thiol-based antioxidants available for human use that have not been evaluated for effects on muscle fatigue. : To test the hypothesis that NACA and ERGO delay skeletal muscle fatigue. ...

ABSTRACT: Despite intense interest in understanding how old age may alter skeletal muscle fatigability, a quantitative examination of the impact of study design on age-related differences in muscle fatigue does not exist. : The purpose of this study was to conduct a systematic review of the differences in muscle fatigue ...

Hypothyroidism causes a variety of changes in the body. Though uncommon, hypothyroidism can present as myopathy. Hoffman's syndrome is a specific, rare form of hypothyroid myopathy, which causes proximal weakness and pseudohypertrophy of muscles.

To evaluate the effects of neurodynamic mobilization on the fluid dynamics of the tibial nerve in cadavers. Evidence showing patients benefit from neural mobilization is limited. Mechanisms responsible for changes in patient symptoms are unclear. Bilateral lower limbs of six unembalmed cadavers (n = 12) were randomized into matched pairs and dissected ...

Roman chair exercises are popular for improving back muscle endurance but do not specifically target back muscles. This study aimed to determine whether an adaptation of the Roman chair exercise would induce more fatigue in back muscles than in hip extensors. For this study, 16 healthy subjects and 18 patients ...

shoulder impairments are often associated with altered scapular kinematics. As muscles control scapular movement, functionally altering muscle performance through fatigue may produce scapular kinematics that mimic those of injured patients. The aim of this study was to examine if changes in scapular tilt, rotation and pro/retraction following two different upper ...

Primate locomotor evolution, particularly the evolution of bipedalism, is often examined through morphological studies. Many of these studies have examined the uniqueness of the primate forelimb, and others have examined the primate hip and thigh. Few data exist, however, regarding the myology and function of the leg muscles, even though ...

Muscle load can affect the performance of concurrent cognitive task. This effect is often explained by limited resources in the voluntary attention system. To examine whether earlier stages of cognitive information processing might be affected, we recorded the mismatch negativity component (MMN) of the auditory event-related brain potential before, during ...

Electromyographic (EMG) spectral parameters and endurance tests for back muscles have long been used to estimate low-back muscle fatigue. The present purpose was to evaluate the test-retest reliability of a fatigue-testing protocol and to investigate associations between activity limitations and fatigue in patients with lumbar disc herniation. To evaluate the ...

Despite 100years of research since the seminal work of Angelo Mosso (1846-1910), our understanding of the interactions between the nervous system and muscle during the performance of fatiguing contractions remains rather rudimentary. Although the nervous system simply needs to provide an activation signal that will elicit the net muscle torque ...

Reactive oxygen and nitrogen species (ROS/RNS) are important for skeletal muscle function under both physiological and pathological conditions. ROS/RNS induce long-term and acute effects and the latter are the focus of the present review. Upon repeated muscle activation both oxygen and nitrogen free radicals likely increase and acutely affect contractile ...

Muscle fatigue is defined as an exercise-induced reduction in the force-generating capacity of muscle. Here, we investigated the effect of muscle fatigue on hand dexterity. Healthy adults (n = 17) gripped and lifted an object (0.342 kg) five times before and after two interventions. The interventions, performed on separate days, ...

Skeletal muscle contraction is basically controlled by Ca(2+) release and its reuptake into the sarcoplasmic reticulum. However, the long-term maintenance of muscle function requires an additional Ca(2+) influx from extracellular. Several mechanisms seem to contribute to the latter process, such as store-operated Ca(2+) entry, stretch-activated Ca(2+) influx and resting Ca(2+) ...

Fingertip force control requires fine coordination of multiple hand muscles within and across the digits. While the modulation of neural drive to hand muscles as a function of force has been extensively studied, much less is known about the effects of fatigue on the coordination of simultaneously active hand muscles. ...

Studies have shown the significant effects of electromagnetic irradiation in the visible region, with laser as an irradiation source. However, the effect of LEDs (light-emitting diodes) irradiation in similar wavelengths is not known. The purpose of this clinical study was to verify the effects of the LED (640 nm with 40 nm ...

We present a low-frequency stimulation method via multi-pad electrodes for delaying muscle fatigue. We compared two protocols for muscle activation of the quadriceps in paraplegics. One protocol involved a large cathode at 30 HZ (HPR, high pulse-rate), and the other involved four smaller cathodes at 16 HZ (LPR, low pulse-rate). ...

Women are often reported to be generally more resistant to fatigue than men for relative-intensity tasks. This has been observed repeatedly for elbow flexors, whereas at the ankle, sex differences appear less robust, suggesting localized rather than systemic influences. Thus, the purpose of this study was to examine sex differences ...

The effects of work strategy and a rest condition on the physiological changes of the erector spinae muscle were studied. Eleven volunteers repeated fatiguing static contractions of holding an industrial box in 30° trunk flexion for a repetition of 12 times interrupted by rests for which the duration was equal ...