Effect of ageing on the electrical and mechanical properties of human soleus motor units activated by the H reflex and M wave

Scaglioni, Gil; Narici, Marco V.; Maffiuletti, Nicola A; Pensini, M.; Martin, Alain

doi:10.1111/j.1469-7793.2003.00649.x

Cited by 58 publications

(38 citation statements)

References 51 publications

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“…F ) with the variability reported in the current study similar to that previously found in older individuals (Scaglioni et al . ). It is possible, however, that the lack of association in these cyclists could also be because the ageing signal is indeed less, or is masked by the more constrained age range (55–79 years) studied here as opposed to those studying wider age ranges including young individuals (20–80 years).…”

Section: Discussionmentioning

confidence: 97%

An investigation into the relationship between age and physiological function in highly active older adults

Pollock

Carter

Velloso

et al. 2015

The Journal of Physiology

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Key Pointsr The relationship between age and physiological function remains poorly defined and there are no physiological markers that can be used to reliably predict the age of an individual.r This could be due to a variety of confounding genetic and lifestyle factors, and in particular to ill-defined and low levels of physical activity.r This study assessed the relationship between age and a diverse range of physiological functions in a cohort of highly active older individuals (cyclists) aged 55-79 years in whom the effects of lifestyle factors would be ameliorated.r Significant associations between age and function were observed for many functions.V O 2 max was most closely associated with age, but even here the variance in age for any given level was high, precluding the clear identification of the age of any individual.r The data suggest that the relationship between human ageing and physiological function is highly individualistic and modified by inactivity.Abstract Despite extensive research, the relationship between age and physiological function remains poorly characterised and there are currently no reliable markers of human ageing. This is probably due to a number of confounding factors, particularly in studies of a cross-sectional nature. These include inter-subject genetic variation, as well as inter-generational differences in nutrition, healthcare and insufficient levels of physical activity as well as other environmental factors. We have studied a cohort of highly and homogeneously active older male (n = 84) and female (n = 41) cyclists aged 55-79 years who it is proposed represent a model for the study of human ageing free from the majority of confounding factors, especially inactivity. The aim of the study was to identify physiological markers of ageing by assessing the relationship between function and age across a wide range of indices. Each participant underwent a detailed physiological profiling which included measures of cardiovascular, respiratory, neuromuscular, metabolic, endocrine and cognitive functions, bone strength, and health and well-being. Significant associations between age and function were observed for many functions. The maximal rate of oxygen consumption (V O 2 max ) showed the closest association with age (r = −0.443 to −0.664; P < 0.001), but even here the variance in age for any given level was high, precluding the clear identification of the age of any individual. The results of this cross-sectional study suggest that even when many confounding variables are removed the relationship between function and healthy ageing is complex and likely to be highly individualistic and that physical activity levels must be taken into account in ageing studies.

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Section: Discussionmentioning

confidence: 97%

An investigation into the relationship between age and physiological function in highly active older adults

Pollock

Carter

Velloso

et al. 2015

The Journal of Physiology

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“…In the present investigation, we recorded the M‐wave evoked concomitantly with the H‐reflex and calculated the M at‐ H max / M max ratio, which is used to control the stability of recording conditions (Schieppati, ). The SOL M at‐ H max represented 11–17% of the SOL M max in all the experimental conditions, in agreement with earlier values reported in the literature (Maffiuletti et al ., ; Scaglioni et al ., ; Grospretre & Martin, ; Cattagni et al ., ). The lack of change in M at‐ H max / M max ratio through the three types of pressure application demonstrated the stability of conditions during H‐reflex recordings.…”

Section: Discussionmentioning

confidence: 99%

H‐reflex and M‐wave recordings: effect of pressure application to the stimulation electrode on the assessment of evoked potentials and subject's discomfort

Cattagni

Merlet

Cornu

et al. 2017

Clin Physio Funct Imaging

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This study aimed to compare the effect of different types of pressure applied to the stimulation electrode on assessing the efficiency of Ia-α-motoneuron transmission of the soleus muscle and the associated discomfort using electrical nerve stimulation. Twelve healthy young adults participated in three experimental sessions (one for each knee angle). The amplitudes of the maximal Hoffmann reflex (H ) and motor potential (M ) were recorded from the soleus muscle at 0°, 30° and 90° knee angles (0° full extension) through three pressure applications to the stimulation electrode: no pressure, pressure with manual application and pressure using adhesive tape. The soleus H /M were calculated to assess the efficiency of Ia-α-motoneuron transmission during varied knee angles and pressure application to the stimulation electrode. At the stimulation intensity evoking soleus H and M , subjects were asked to orally provide a value between 'no discomfort' (0) and 'worst possible discomfort' (10). The application of pressure on the stimulation electrode, particularly using adhesive tape, decreased both the stimulation intensity needed to evoke an electrophysiological response and the associated self-reported discomfort (P<0·05), while the H /M remained constant. At the stimulation intensity evoking M , the electrical stimulation appeared to be more painful at 0° knee angle compared with 30° and 90° angles (P<0·01). To conclude, this study showed that a knee flexion and a pressure application to the stimulation electrode, especially using tape pressure, are recommended in the objective to reduce the patient/subjects' discomfort when eliciting evoked potentials on soleus muscle.

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“…This increased vulnerability to falls could be a consequence of aging-related effects on sensorimotor function. Changes such as decreased muscle strength and power,27 longer latencies, lower magnitudes, and increased burst durations of postural responses,28 and attenuated neural excitability and weaker reflex torques,29 have been implicated in heightened fall risk with aging. These deteriorations may alter older adults’ regular movement patterns or weaken their reactions,9, 30 causing deficiencies in controlling slip severity, resisting limb collapse, and re-establishing stability,15, 31, 32 leading to more falls, regardless of task.…”

Section: Discussionmentioning

confidence: 99%

Inoculation Against Falls: Rapid Adaptation by Young and Older Adults to Slips During Daily Activities

Pai

Bhatt

Wang

et al. 2010

Archives of Physical Medicine and Rehabilitation

109

151

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Objective To determine whether aging diminishes one’s ability to rapidly learn to resist falls on repeated-slip exposure across different activities of daily living. Design Quasi-experimental controlled trial. Setting Two university-based research laboratories. Participants Young (n=35) and older (n=38) adults underwent slips during walking. Young (n=60) and older (n=41) adults underwent slips during sit-to-stands. All (N=174) were healthy and community-dwelling. Intervention Low-friction platforms induced unannounced blocks of 2–8 repeated slips, interspersed with blocks of 3–5 nonslip trials, during the designated task. Main Outcome Measures The incidence of falls and balance loss. Dynamic stability (based on center-of-mass position and velocity) and limb support (based on hip height) 300 ms after slip onset. Results Under strictly controlled, identical low-friction conditions, all participants experienced balance loss but older adults were over twice as likely as young to fall on the first, unannounced, novel slip in both tasks. Independent of age or task, participants adapted to avoid falls and balance loss, with most adaptation occurring in early trials. By the fifth slip, the incidence of falls and balance loss was less than 5% and 15%, respectively, regardless of age or task. Reductions in falls and balance loss for each task were accomplished through improved control of stability and limb support in both age groups. A rapidly-reversible, age- and task-dependent waning of motor learning occurred after a block of nonslip trials. Adaptation to walk-slips reached steady-state in the second slip block, regardless of age. Conclusions The ability to rapidly acquire fall-resisting skills on repeated-slip exposure remains largely intact at older ages and across functional activities. Thus, repeated-slip exposure might be broadly effective in inoculating older adults against falls.

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Effect of ageing on the electrical and mechanical properties of human soleus motor units activated by the H reflex and M wave

Cited by 58 publications

References 51 publications

An investigation into the relationship between age and physiological function in highly active older adults

An investigation into the relationship between age and physiological function in highly active older adults

H‐reflex and M‐wave recordings: effect of pressure application to the stimulation electrode on the assessment of evoked potentials and subject's discomfort

Inoculation Against Falls: Rapid Adaptation by Young and Older Adults to Slips During Daily Activities

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