Somatosensory & motor research最新文献

Purpose: This study aimed to identify the contribution of the common synaptic drives to motor units during obstacle avoidance, using coherence analysis between a-pair electromyography (EMG) signals (EMG-EMG coherence).

Materials and methods: Fourteen healthy volunteers walked on a treadmill with and without obstacle avoidance. During obstacle gait, subjects were instructed to step over an obstacle with their right leg while walking that would randomly and unpredictably appear. Surface EMG signals were recorded from the following muscles of the right leg: the proximal and distal ends of tibialis anterior (TAp and TAd), biceps femoris (BF), semitendinosus (ST), lateral gastrocnemius (LG), and medial gastrocnemius (MG). Beta-band (13-30 Hz) EMG-EMG coherence was analysed.

Results: Beta-band EMG-EMG coherence of TAp-TAd during swing phase and BF-ST during pre and initial swing phase when stepping over an obstacle were significantly higher compared to normal gait (both p < 0.05). Beta-band EMG-EMG coherence of TAp-TAd, BF-ST, and LG-MG during stance phase were not significantly different between the two gait conditions (all p > 0.05).

Conclusions: The present findings suggest increased common synaptic drives to motor units in ankle dorsiflexor and knee flexor muscles during obstacle avoidance. It also may reflect an increased cortical contribution to modify the gait patterns to avoid an obstacle.

Aim: This study aimed to compare the acute effects of different methods on ankle joint range of motion (ROM) in older adults.

Materials and methods: Seventy-eight older adults were randomly divided into three groups. After the warming-up, static stretching, proprioceptive neuromuscular facilitation (PNF) contract-relax, and roller massage were applied, at the same period. Before application, immediately after, 10 and 20 min after application, ankle joint dorsiflexion ROM was measured in the weight-bearing position.

Results: No statistically significant difference between the groups in demographic characteristics and baseline ankle ROM (p = 0.413). In all groups, post-application measurements revealed increased ankle joint motion (p < 0.0125). Groups were compared, and a statistically significant difference between the three groups was found (p < 0.05). There was no significant difference in the change of ROM between the Static Stretching and PNF Stretching Groups in the change of ROM group comparisons (p = 0.089). There was a statistically significant difference in ROM changes Roller Massage Group and both Static Stretching and the PNF Stretching Group (p = 0.001).

Conclusion: The acute effects of roller massage, on ankle ROM, were superior to static and PNF stretching. The application of roller massage, which was shown to be an effective method for increasing ROM, can be safely applied in physiotherapy programs for older adults.

Aim of the study: Brain-computer interfaces (BCIs) may help patients with severe neurological deficits communicate with the external world. Based on microelectrocorticography (µECoG) data recorded from the primary somatosensory cortex (S1) of unrestrained behaving rats, this study attempts to decode lever presses in a psychophysical detection task by using machine learning algorithms.

Materials and methods: 16-channel Pt-Ir microelectrode arrays were implanted on the S1 of two rats, and µECoG was recorded during a vibrotactile yes/no detection task. For this task, the rats were trained to press the right lever when they detected the vibrotactile stimulus and the left lever when they did not. The multichannel µECoG data was analysed offline by time-frequency methods and its features were used for binary classification of the lever press at each trial. Several machine learning algorithms were tested as such.

Results: The psychophysical sensitivities (A') were similar and low for both rats (0.58). Rat 2 (B'': -0.11) had higher bias for the right lever than Rat 1 (B'': - 0.01). The lever presses could be predicted with accuracies over 66% with all the tested algorithms, and the highest average accuracy (78%) was with the support vector machine.

Conclusion: According to the recent studies, sensory feedback increases the benefit of the BCIs. The current proof-of-concept study shows that lever presses can be decoded from the S1; therefore, this area may be utilised for a bidirectional BCI in the future.

Aim of the study: Sensory gating is a human higher cognitive function that serves to suppress excessive sensory information and prevent brain overactivity. To elucidate this function, a paired-pulse stimulation paradigm has been used while recording electroencephalography (EEG), and evaluated as an amplitude ratio of responses to a second stimulus (S2) over responses to the first stimulus (S1). The present study investigated the effects of the inter-stimulus interval (ISI) and inter-trial interval (ITI) on somatosensory gating using somatosensory-evoked potentials (SEPs).

Methods: In Experiment 1, ISI was set at five conditions: 200, 400, 600, 800, and 1000 ms. In Experiment 2, ITI was set at four conditions: 1, 2, 4, and 8 s.

Results: ISI affected the S2/S1 amplitude ratios of P22 and N27 at C3' and N30 at Fz, and these S2/S1 amplitude ratios decreased the most under the 200 and 400-ms conditions. ITI affected the S2/S1 amplitude ratios of P22, N27, and N60 at C3', and especially, the somatosensory gating did not work under the 1-s condition. These results suggest that not all SEP components are modulated in the same manner with changing ISI and ITI. The effects of ISI and ITI independently affected the somatosensory gating.

Conclusions: Based on our findings, preferable parameters are 200-400 ms for ISI and 4 s or longer for ITI to evaluate the functional mechanisms on somatosensory gating in SEPs.

Purpose/aim: To investigate the relationship of pain intensity, disability level, physical activity level, and body awareness with kinesiophobia in pregnant women with low back pain (LBP).

Materials and methods: This cross-sectional study was conducted in the obstetrics and gynaecologic clinic of a tertiary centre. Eighty-six pregnant women were included in the study. Pain intensity, disability level, physical activity, body awareness, and kinesiophobia were assessed with a Visual Analogue Scale, the Oswestry Disability Index (ODI), the International Physical Activity Questionnaire-Short Form (IPAQ-SF), the Body Awareness Questionnaire (BAQ), and the Tampa Scale for Kinesiophobia (TSK), respectively.

Results: Kinesiophobia score was high in pregnant women with LBP (40.01 ± 9.02). In pregnant women with LBP, a weak positive correlation was found between kinesiophobia with mean intensity of LBP (r = 0.339, p = 0.001) and intensity of LBP in activity (r = 0.283, p = 0.008); a moderate positive correlation between kinesiophobia and disability score (r = 0.539, p = 0.001); and a weak negative correlation between kinesiophobia and physical activity level (r = -0.308, p = 0.004) and body awareness (r = -0.324, p = 0.002). There was no relationship between kinesiophobia and intensity of LBP at rest (r = 0.160, p = 0.142) and nocturnal LBP intensity (r = 0.176, p = 0.105).

Conclusions: LBP intensity, disability level, physical activity level, and body awareness were significantly correlated with kinesiophobia in pregnant women with LBP. Therefore, kinesiophobia may be addressed as an important issue in pregnancy education programs.