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Postural Perturbations (postural + perturbation)
Selected AbstractsPostural response of the pelvic floor and abdominal muscles in women with and without incontinence,NEUROUROLOGY AND URODYNAMICS, Issue 3 2007Michelle D. Smith Abstract Aims To determine whether activity of the pelvic floor (PF) and abdominal muscles differs between continent and incontinent women in response to a postural perturbation with a moderately full or empty bladder. Methods Electromyographic (EMG) activity of the PF and abdominal muscles was recorded with surface electrodes prior to and after a postural perturbation in which a 1 kg weight was dropped 30 cm into a bucket held by the subject. Perturbations were applied to the trunk in trials in which the timing of the weight drop was unknown (unexpected) or predictable (expected). Trials were performed with the bladder empty, and when the subject reported a sensation of moderate bladder fullness after drinking between 200 and 1,000 ml of water. Results Women with incontinence demonstrated increased PF EMG compared to continent women both prior to and during the postural response associated with unexpected loading. In addition, obliquus externus abdominis EMG was increased in incontinent women during these trials. When the bladder was moderately full, PF EMG decreased, whereas abdominal muscle EMG tended to increase. Conclusions These data suggest that women with incontinence have increased PF and abdominal muscle activity associated with postural perturbations. This finding challenges the clinical assumption that incontinence is associated with reduced PF muscle activity, and suggests that training control and coordination of abdominal muscle activity may be important in treatment of this condition. The contrasting effects of increased bladder volume on PF and abdominal muscle EMG are likely to present further challenges to the maintenance of continence. Neurourol. Urodynam. 26:377,385, 2007. © 2007 Wiley-Liss, Inc. [source] Soleus T reflex modulation in response to spinal and tendinous adaptations to unilateral lower limb suspension in humansACTA PHYSIOLOGICA, Issue 3 2008O. R. Seynnes Abstract Aim:, To investigate the influence of tendinous and synaptic changes induced by unilateral lower limb suspension (ULLS) on the tendon tap reflex. Methods:, Eight young men underwent a 23-day period of ULLS. Muscle cross-sectional area (CSA), torque and electromyographic (EMG) activity of the plantar flexor muscles (normalized to the M wave), Achilles tendon,aponeurosis mechanical properties, soleus (SOL) H and T reflexes and associated peak twitch torques were measured at baseline, after 14 and 23 days of ULLS, and 1 week after resuming ambulatory activity. Results:, Significant decreases in muscle CSA (,9%), in maximal voluntary torque (,10%) and in the associated SOL EMG activity (,16%) were found after ULLS (P < 0.05). In addition to a 36% (P < 0.01) decrease in tendon,aponeurosis stiffness, normalized H reflex increased by 35% (P < 0.05). An increase in the slope (28%, P < 0.05) and intercept (85%, P < 0.05) of the T reflex recruitment curve pointed to an increase in the gain and to a decrease in the sensitivity of this reflex, possibly resulting from the decrease in the tendon,aponeurosis stiffness at low forces. Following ULLS, changes in tendinous stiffness correlated with changes in neuromuscular efficiency (peak twitch torque to reflex ratio) at higher tendon tap forces. Conclusion:, These findings point out the dual and antagonistic influences of spinal and tendinous adaptations upon the tendon tap reflex in humans under conditions of chronic unloading. These observations have potential implications for the sensitivity of the short-latency Ia stretch response involved in rapid compensatory contractions to unexpected postural perturbations. [source] Assessing the balance capabilities of people with profound intellectual disabilities who have experienced a fallJOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 4 2007L. Hale Abstract Background Although it is common for people with intellectual disability (ID) to fall, the reasons for this have not yet been identified. This pilot study aimed to explore the balance capabilities of a sample of adults with profound ID who had experienced a fall, in order to identify possible reasons for falling and to identify potential tests that could be used to quantify balance capabilities in this population group. Methods The neuromuscular systems and balance capabilities of 20 adults with profound ID were comprehensively assessed with a battery of tests, including computerized posturography. Results Of the 20 participants, 15 described themselves as frequent fallers, and 10 participants reported serious injuries as a result of falling. Formalized assessment of the neuromuscular and balance capabilities proved to be challenging, with many participants unable to comprehend what was required of them in the performance of a number of the tests. All participants were observed to have an abnormal pattern of walking. Nine participants completed posturography testing, the main finding of which was that low motor control composite scores indicated a slowing of motor responses to postural perturbations. Other potential risk factors identified were concurrent medical problems, medication, the context and environment of falling, movement impulsiveness and distractibility, and visual deficits. Conclusion The reason why people with ID frequently fall appears complex and multifactorial. Larger studies are required to verify the potential risk factors identified in this pilot study. Many of the standardized outcome measures commonly used in physiotherapy practice to quantify balance capabilities are not suitable for use in this population group, as participants found it difficult to comprehend what was required of them. Allowing the person to become familiarized with both the test and the tester may help to alleviate this problem. Videotaping and quantifying observations of strategies people use to perform common movements such as walking or turning maybe a more appropriate measurement tool of balance capabilities of people with ID than current standardized measures. This method would require rigorous development. [source] Postural response of the pelvic floor and abdominal muscles in women with and without incontinence,NEUROUROLOGY AND URODYNAMICS, Issue 3 2007Michelle D. Smith Abstract Aims To determine whether activity of the pelvic floor (PF) and abdominal muscles differs between continent and incontinent women in response to a postural perturbation with a moderately full or empty bladder. Methods Electromyographic (EMG) activity of the PF and abdominal muscles was recorded with surface electrodes prior to and after a postural perturbation in which a 1 kg weight was dropped 30 cm into a bucket held by the subject. Perturbations were applied to the trunk in trials in which the timing of the weight drop was unknown (unexpected) or predictable (expected). Trials were performed with the bladder empty, and when the subject reported a sensation of moderate bladder fullness after drinking between 200 and 1,000 ml of water. Results Women with incontinence demonstrated increased PF EMG compared to continent women both prior to and during the postural response associated with unexpected loading. In addition, obliquus externus abdominis EMG was increased in incontinent women during these trials. When the bladder was moderately full, PF EMG decreased, whereas abdominal muscle EMG tended to increase. Conclusions These data suggest that women with incontinence have increased PF and abdominal muscle activity associated with postural perturbations. This finding challenges the clinical assumption that incontinence is associated with reduced PF muscle activity, and suggests that training control and coordination of abdominal muscle activity may be important in treatment of this condition. The contrasting effects of increased bladder volume on PF and abdominal muscle EMG are likely to present further challenges to the maintenance of continence. Neurourol. Urodynam. 26:377,385, 2007. © 2007 Wiley-Liss, Inc. [source] | ||||||||||