Hypoventilation during passive leg movement in spinal cord-injured humans.

We examined ventilatory response during passive walking-like exercise in the standing posture in complete spinal cord-injured humans and found that ventilatory equivalent for O(2) uptake, which would be related to the sensation of breathlessness, was lower during passive exercise than during quiet standing.

My thoughts through a robot's eyes: an augmented reality-brain-machine interface.

A brain-machine interface (BMI) uses neurophysiological signals from the brain to control external devices, such as robot arms or computer cursors. Combining augmented reality with a BMI, we show that the user's brain signals successfully controlled an agent robot and operated devices in the robot's environment. The user's thoughts became reality through the robot's eyes, enabling the augmentation of real environments outside the anatomy of the human body.

Unusual blood pressure response during standing therapy in tetraplegic man.

We report a case of an individual with cervical spinal cord injury who showed a unique blood pressure response during passive standing and passive walking-like leg movement, i.e., hypertension with standing and hypotension with leg movement.

Hyperventilation during orthostatic challenge in spinal cord-injured humans.

Objective: To determine whether arterial hypotension is related to hyperventilation during standing in individuals with complete spinal cord injury (SCI).

Methods: Sixteen individuals with SCI (thoracic 1 to thoracic level 12, ASIA grade: A) and 18 able-bodied individuals participated in this study. Individuals with SCI were divided into a group with injury level at or above thoracic (T) 7 [higher SCI (HSCI), n = 9] and a group with injury level at or below T10 (lower SCI, n = 7).

Metal bar prevents phantom limb motion: case study of an amputation patient who showed a profound change in the awareness of his phantom limb.

This case report describes an amputee (patient A.S., a 60-year-old male forelimb amputee) who had an extraordinary experience with a phantom limb.

Visual stimuli for the P300 brain-computer interface: a comparison of white/gray and green/blue flicker matrices.

Objective: The white/gray flicker matrix has been used as a visual stimulus for the so-called P300 brain-computer interface (BCI), but the white/gray flash stimuli might induce discomfort. In this study, we investigated the effectiveness of green/blue flicker matrices as visual stimuli.

Methods: Ten able-bodied, non-trained subjects performed Alphabet Spelling (Japanese Alphabet: Hiragana) using an 8 x 10 matrix with three types of intensification/rest flicker combinations (L, luminance; C, chromatic; LC, luminance and chromatic); both online and offline performances were evaluated.

Pressor response to passive walking-like exercise in spinal cord-injured humans.

Objective: To examine blood pressure responses during passive walking-like exercise in the standing posture (PWE) in spinal cord-injured (SCI) humans.

Methods: Twelve motor-complete SCI individuals (cervical level 6 to thoracic level 12, ASIA grade: A or B) and twelve able-bodied controls (CON) participated in this study. SCI individuals were divided into a group with injury level at or above thoracic (T) 6 (HSCI, n = 7) and a group with injury level at or below T10 (LSCI, n = 5).

Metaboreceptor-mediated muscle oxygen saturation during recovery following isometric handgrip exercise.

The aim of the present study was to determine whether oxygen supply to non-exercised muscle during recovery following fatiguing exercise is influenced by accumulated metabolites within exercised muscle. Twelve healthy male subjects performed 2-min isometric handgrip exercise at 40% maximal voluntary contraction with their right hand and the exercise was followed by a 3-min recovery period. Muscle oxygen saturation (SmO(2)) determined by near-infrared spatially resolved spectroscopy was used as an index of oxygen supply to non-exercised muscle and was measured in biceps brachii and tibialis anterior muscles on the left side.

Facilitation of the soleus stretch reflex induced by electrical excitation of plantar cutaneous afferents located around the heel.

Previous studies have demonstrated that plantar cutaneous afferents can adjust motoneuronal excitability, which may contribute significantly to the control of human posture and locomotion. However, the role of plantar cutaneous afferents with respect to their location specificity in modulating the mechanically induced stretch reflex still remains unclear. In the present study, it was hypothesized that electrical stimulation of the ipsilateral heel region of the foot is followed by a modulation of spinal excitability, leading to a facilitation of the soleus motor output.

Kinematics and kinetics of the racket-arm during the soft-tennis smash under match conditions.

The purposes of this study were to (a) describe the racket-arm kinematics and kinetics of the soft-tennis smash during match rallies, and (b) assess the characteristics of this smash vs. the laboratory-simulated smash of our previous study. In the current study we recorded soft-tennis smash motions during match play of the 3rd East Asian Games.

Effect of a lateral wedge on joint moments during gait in subjects with recurrent ankle sprain.

This study assessed the biomechanic effects of wearing a lateral wedge on the subtalar joint moment during gait in athletes with and without an unstable lateral ankle. A crossover design was applied whereby 50 collegiate males walked with two different wedges: a 0 degrees control wedge and a 6 degrees lateral wedge. We investigated frontal plane angles and moments at the subtalar joint and the knee joint, as well as ground reaction forces and center of pressure excursion.

Testing Bayesian models of human coincidence timing.

A sensorimotor control task often requires an accurate estimation of the timing of the arrival of an external target (e.g., when hitting a pitched ball).

Alternate leg movement amplifies locomotor-like muscle activity in spinal cord injured persons.

It is now well recognized that muscle activity can be induced even in the paralyzed lower limb muscles of persons with spinal cord injury (SCI) by imposing locomotion-like movements on both of their legs. Although the significant role of the afferent input related to hip joint movement and body load has been emphasized considerably in previous studies, the contribution of the "alternate" leg movement pattern has not been fully investigated. This study was designed to investigate to what extent the alternate leg movement influenced this "locomotor-like" muscle activity.

Effect of the walking speed to the lower limb joint angular displacements, joint moments and ground reaction forces during walking in water.

Purpose: The purpose of this study was to compare the changes in ground reaction forces (GRF), joint angular displacements (JAD), joint moments (JM) and electromyographic (EMG) activities that occur during walking at various speeds in water and on land.

Method: Fifteen healthy adults participated in this study. In the water experiments, the water depth was adjusted so that body weight was reduced by 80%.

Potential impact of orthotic gait exercise on natural killer cell activities in thoracic level of spinal cord-injured patients.

Study Design: Prospective before-after trial.

Objective: To examine the changes of natural killer (NK) cell activity in response to orthotic gait exercise in thoracic level of spinal cord-injured (SCI) patients.

Setting: National Rehabilitation Center for Persons with Disabilities, Japan.

Stretch reflex excitability of the anti-gravity ankle extensor muscle in elderly humans.

Aim: To examine whether the stretch reflex excitability of the soleus muscle changes with age, stretch reflexes at rest (REST) and during weak voluntary contractions (ACT) were elicited in 18 older and 14 younger subjects.

Method: The amplitude of the stretch reflex responses and gain, defined as the gradient of the regression line for the relation between stretch reflex responses against the angular velocity of the applied perturbation, were evaluated in each short-latency (M1) and two long-latency components (M2 and M3).

Results: It was found that in the older group, both the amplitude and gain of the M1 component did not change from the REST to the ACT conditions, whereas in the younger group both variables significantly increased from the REST to ACT conditions.