Estimation of the number of motor units based on macro-EMG.

Koning, P. de; Wieneke, G.H.; Spijk, D. van der Most van; Huffelen, Alexander C. van; Gispen, Willem Hendrik; Jennekens, F. G. I.

doi:10.1136/jnnp.51.3.403

Cited by 54 publications

(30 citation statements)

References 22 publications

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“…21,60,93 The macro-EMG technique has shown an increase in MU size in the vastus lateralis, the tibialis anterior, and the biceps brachii from subjects older than age 60 years, indirectly indicating an increased number of muscle fibers per motor unit. 15,79,80 At the microscopic level of muscle analysis, there is evidence of age-related neuropathic changes, such as small angulated fibers and grouped atrophy, in samples from old or very old individuals. 26,45,54,56,76,85,86 In comparisons between older adults and young subjects, whole muscle analysis via cadaveric or radiological observations has shown that thigh and leg muscles undergo significant size reductions over time, 33,34,44,56,91 which are consistent in timing and magnitude to the loss of strength.…”

Section: Age-related Loss Of Functional Cells From the Motor Systemmentioning

confidence: 99%

Aging of the human neuromuscular system

2001

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Loss of cells from the motor system occurs during the normal aging process, leading to reduction in the complement of motor neurons and muscle fibers. The latter age-related decrease in muscle mass has been termed "sarcopenia" and is often combined with the detrimental effects of a sedentary lifestyle in older adults, leading to a significant reduction in reserve capacity of the neuromuscular system, which is the primary subject of this review. Clear evidence of this aging effect is seen when voluntary or stimulated muscle strength is compared across the adult lifespan, with a steady decline of approximately 1-2% per year occurring after the sixth decade. Interestingly, when compared with isometric contractions, the effect of aging is more pronounced for concentric movements and less for eccentric movements (i.e., muscle shortening versus lengthening). This phenomenon appears to be linked to the stiffer muscle structures and prolonged myosin crossbridge cycles of aged muscles. It is encouraging that the capability of physiological adaptations in the motor pathways remains into very old age--when an appropriate exercise stimulus is given--and long-term prevention strategies are advocated to avoid excessive physical impairments and activity restrictions in this age group.

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Section: Age-related Loss Of Functional Cells From the Motor Systemmentioning

confidence: 99%

Aging of the human neuromuscular system

2001

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“…Although developed decades ago, 18,25,33,49,58 quantitative techniques have rarely been used in clinical neurophysiology to date. There is little indication in a traditional clinical neurophysiology practice, but several of the methods have been liberally applied in research over the years, mainly to observe changes over time.…”

Section: Clinical Assessmentmentioning

confidence: 99%

“…Isolating the target muscle can be achieved by recording with the needle electrode shaft (macro-EMG, 50 Conmac, 28 or concentric cannula) rather than the surface electrode. At our center, we have used a macro-EMG needle (macro-MUNE), described and validated by de Koning et al in 1988 18 using the spike-triggered average 3,5 (STA) MUNE approach. If the muscle is large, then we sample at intervals of 0.5 cm perpendicular to the motor point.…”

Section: Donor Nerve: Neurophysiological Evaluationmentioning

confidence: 99%

A neurophysiological approach to nerve transfer to restore upper limb function in cervical spinal cord injury

Mandeville¹,

Brown

Sheean³

2017

Neurosurgical Focus

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A successful nerve transfer surgery can provide a wealth of benefits to a patient with cervical spinal cord injury. The process of surgical decision making ideally uses all pertinent information to produce the best functional outcome. Reliance on clinical examination and imaging studies alone can miss valuable information on the state of spinal cord health. In this regard, neurophysiological evaluation has the potential to effectively gauge the neurological status of even select pools of anterior horn cells and their axons to small nerve branches in question to determine the potential efficacy of their use in a transfer. If available preoperatively, knowledge gained from such an evaluation could significantly alter the reconstructive surgical plan and avoid poor results. The authors describe their institution’s approach to the assessment of patients with cervical spinal cord injury who are being considered for nerve transfer surgery in both the acute and chronic setting and broadly review the neurophysiological techniques used.

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“…Estudos que utilizaram eletromiografia (STALBERG, 1980) ou técnicas para estimar o número de unidades motoras (DOHERTY et al, 1995) demonstraram perdas substanciais das unidades motoras ativas em músculos das extremidades superiores e inferiores. (DEKONING et al, 1988;BROWN, 2002). Esse processo é apontado como outro importante fator em explicar a perda de força muscular característica do avançar da idade.…”

Section: Discussionunclassified