Explore chapters and articles related to this topic
Neural engineering
Published in Alex Mihailidis, Roger Smith, Rehabilitation Engineering, 2023
As an alternative to all of these therapies, electrical stimulation of the saphenous nerve (SAFN) is being investigated as a means of modulating bladder function. The SAFN is a purely sensory nerve that branches off the femoral nerve trunk. It innervates the medial skin surface of the lower leg and projects proximally to the lumbar spinal cord (L2–L3 in humans). The projection of the SAFN to the lumbar nerve roots is notably different from that of the pudendal nerve and the tibial nerve. And while the precise mechanism is not yet known, it is hypothesized that the SAFN electrically activates a different bladder-inhibitory reflex than those evoked by pudendal, sacral, and tibial nerve stimulation. Evidence of an inhibitory SAFN-to-bladder reflex has been shown in urethane anesthetized rats (Moazzam and Yoo 2018), where low-amplitude electrical pulses applied between 10 Hz and 20 Hz resulted in significant increases in bladder capacity and also the interval between successive bladder contractions. The effects of SAFN stimulation were also demonstrated in a pilot clinical study involving OAB patients (Macdiarmid, John, and Yoo 2018). This recently published study showed that 87.5% of patients responded positively to percutaneous SAFN stimulation, which was applied weekly for 12 weeks. Patients showed significant improvements in every quality-of-life measure (OAB-q survey) and showed particularly notable reductions in nighttime symptoms (nocturia and urge incontinence). This novel therapeutic approach is being further clinically validated and commercialized.
Advances in surgery for bursitis of the hip joint in adults
Published in K. Mohan Iyer, Hip Joint in Adults: Advances and Developments, 2018
This is a large bursa that lies between the iliopsoas muscle and the pelvis. Posteriorly and above is the iliopectineal eminence, while below is the capsule of the hip joint. It usually accompanies the femoral nerve and frequently communicates with the hip joint. Clinically there may be pain and tenderness in the medial part of Scarpa’s triangle, while in its late stages when there is suppuration, fluctuation may be demonstrable. The swelling may be large enough to obliterate the normal inguinal groove, or it may compress the femoral nerve to give rise to referred pain down the leg, usually the knee, as in hip joint disease. Flexion of the hip elicits pain, while with extension the pain increases. The diagnosis of this condition from hip joint disease and from psoas abscess may be extremely difficult. Always remember the presence of an obturator hernia, before considering aspiration of the swelling in this region.
Functional Anatomy and Biomechanics
Published in Emeric Arus, Biomechanics of Human Motion, 2017
The principal flexors are iliopsoas, rectus femoris, and tensor fasciae latae which flexes the pelvis when the thigh is flexed a little bit and the last flexor is the sartorius. The secondary flexors are gluteus medius and minimus. The primary nerve for the movement of flexion is the femoral nerve. The secondary nerves are gluteal superior and obturator nerve.
Does creatine supplementation affect recovery speed of impulse above critical torque?
Published in European Journal of Sport Science, 2023
Leonardo Henrique Perinotto Abdalla, Ryan Michael Broxterman, Thomas Jackson Barstow, Camila Coelho Greco, Benedito Sérgio Denadai
The electrically evoked contractions were induced by a high voltage constant current stimulator (DS7A; Digitimer, Welwyn Garden City, United Kingdom), which delivered a unique square wave stimulus of 1 ms duration at (1 Hz), with a voltage maximum of 400 V, to the femoral nerve. A monopolar cathode (0.5 cm in diameter, Dermatrode; American Imex, Irvine, CA, USA) was placed over the femoral nerve at the level of the femoral triangle below the inguinal ligament. The anode (5 cm x 10 cm; Compex, Ecublens, Switzerland) was placed at the bottom of the gluteal fold opposite the cathode (Neyroud et al., 2012). These sites were marked on the skin and used as a reference for subsequent visits. The intensity for the supramaximal stimuli was determined during familiarization, increasing the intensity of the current until the maximum contraction torque was obtained (that is, when an increase in the intensity of the stimulus did not produce an increase in the amplitude of the contraction). The stimulation intensity was then increased by 30% to guarantee supramaximal stimuli. Every 12 contractions (i.e. 1 min) during the ET + 10% tests and immediately after task failure, electrical stimuli were administered 1.5 s into the MVC and 1.5 s after the MVC, to obtain measures of superimposed and potentiated contraction torques, respectively. However, for this retrospective analysis only the data related to the electrical stimulus applied 1.5 s after the MVC were used, as these are assessments of peripheral fatigue.
Corticospinal and intracortical excitability is modulated in the knee extensors after acute strength training
Published in Journal of Sports Sciences, 2022
Razie J Alibazi, Ashlyn K Frazer, Alan J Pearce, Jamie Tallent, Janne Avela, Dawson J Kidgell
Direct muscle responses were obtained under resting conditions from the right rectus femoris by supra-maximal percutaneous electrical stimulation of the femoral nerve approximately 3–5 cm below the inguinal ligament in the femoral triangle. A digitimer (Hertfordshire. UK) DS7A constant-current electrical stimulator (pulse duration 1 ms) was used to deliver each electrical pulse. The cathode was placed over the femoral nerve in the femoral triangle with the anode positioned between the greater trochanter and iliac crest. An increase in current strength was applied to the femoral nerve until there was no further increase in the amplitude of sEMG response (MMAX). To ensure maximal responses, the current was increased an additional 20% and the average MMAX was obtained from five stimuli, with a period of 6–9 s separating each stimulus (Ansdell, Brownstein et al. 2020)
Fatigue reduces the complexity of knee extensor torque during fatiguing sustained isometric contractions
Published in European Journal of Sport Science, 2019
Jamie Pethick, Samantha L. Winter, Mark Burnley
Each visit began with the instrumentation of the participants and the (re-)establishment of the correct dynamometer seating position and supramaximal stimulation response. Maximal torque was established as in Pethick et al. (2015). Participants performed a series of brief (3 s) MVCs, separated by a minimum of 60 s rest. The first MVC was used to establish the fresh maximal EMG signal, against which subsequent signals were normalised (Data analysis; see below). The second and third MVCs were performed with femoral nerve stimulation. During a plateau in torque, ∼1.5 s into the contraction, a doublet was superimposed on the contraction to test its maximality and provide the fresh voluntary activation. A further doublet was delivered at rest 2 s after the contraction to establish the fresh potentiated doublet torque (Data analysis; see below). All subsequent contractions with femoral nerve stimulation were conducted in this manner. Participants then rested for 10 min before performing either the maximal or submaximal test.