Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
OBJECTIVE: To estimate the processing time and neuromuscular delay required to extract and process sensory information from the ankle in order to coordinate an upper extremity movement sequence. METHODS: Nineteen able-bodied subjects were tested on their ability to perform a motor task that involved extension of their left index finger when their left ankle was passively plantar flexed at random velocities through a predetermined target angle. RESULTS: We found that the able-bodied subjects were able to adjust their finger responses up to ankle velocities of 70 degrees /s (300 ms).
This review presents an analysis of the sensory and motor mechanisms as they are now understood that cause the immobility reflex (IR). Of the sensory systems that conceivably could trigger and sustain the IR, as commonly induced experimentally by inversion and manual restraint, evidence has been presented to eliminate some senses (vestibular, vision, sound, many visceral sensations, olfaction, taste, temperature), while incriminating tactile and proprioceptive influences.
Subjects highly (Highs) and low susceptible to hypnosis (Lows) show different imagery and attentional capabilities and also peculiar somatomotor, vegetative and electroencephalographic differences in basal and task conditions. Since attention is one of the main component of hypnotic susceptibility and also a relevant factor for postural control, the aim of the experiment was to study actual differences between Highs and Lows at the eyes closure during upright stance. Visual and motor imagery as well as attentional/disattentional capabilities were evaluated through psychological tests.
The International Journal of Clinical and Experimental Hypnosis
Previous studies on the role of hypnotizability in postural control indicate that the body sway of subjects with high or low hypnotizability to hypnosis is differentially modulated by eye closure. The aim of this study was to investigate whether hypnotizability also modulates the postural response to electrical vestibular stimulation and to head rotation in nonhypnotized individuals.
The aim of the experiment was to investigate whether the peculiar attentional/imagery abilities associated with susceptibility to hypnosis might make postural control in highly hypnotizable subjects (Highs) that are less vulnerable to sensory alteration than in individuals with low hypnotic susceptibility (Lows). The movement of the centre of pression (CoP) was monitored in Highs and Lows during alteration of the visual and leg proprioceptive input. The two groups responded differently to eyes closure and to an unstable support and the CoP movement was generally larger and faster in Highs.
How many persons need tactile support à la Milton H. Erickson to achieve arm levitation during hypnosis? How do these differ from those who do not need it? Hypnotic arm levitation was suggested three times consecutively to 30 medium suggestible students. Sixteen succeeded without any tactile support; 7 needed it one or two times; 5 needed it every time; and 2 achieved no arm levitation at all. Participants without any tactile support went more quickly into deeper hypnosis, experienced more involuntariness, less effort, and had higher electrodermal activity.
Muscle spindles contribute to sensorimotor control by supplying feedback regarding muscle length and consequently information about joint position. While substantial study has been devoted to determining the position sensitivity of spindles in limb muscles, there appears to be no data on their sensitivity in the low back. We determined the relationship between lumbar paraspinal muscle spindle discharge and paraspinal muscle lengthening estimated from controlled cranialward movement of the L(6) vertebra in anesthetized cats.
Journal of Manipulative and Physiological Therapeutics
OBJECTIVE: The lumbar facet joint capsule (FJC) is innervated with mechanically sensitive neurons and is thought to contribute to proprioception and pain. Biomechanical investigations of the FJC have commonly used human cadaveric spines, whereas combined biomechanical and neurophysiological studies have typically used nonhuman animal models.
Increasing our knowledge regarding intrafusal fiber distribution and physiology of paraspinal proprioceptors may provide key insights regarding proprioceptive deficits in trunk control associated with low back pain and lead to more effective clinical intervention. The use of vertebral movement as a means to reliably stretch paraspinal muscles would greatly facilitate physiological study of paraspinal muscle proprioceptors where muscle tendon isolation is either very difficult or impossible.
Physical Therapy in Sport: Official Journal of the Association of Chartered Physiotherapists in Sports Medicine
OBJECTIVES: To determine the immediate effects of modified Proprioceptive Neuromuscular Facilitation (PNF) stretching (group I) versus Myofascial Trigger Point (MTrP) therapy plus modified PNF stretching (group II) in comparison to a control group receiving no treatment. DESIGN: Randomized, assessor-blind, (3 x 4) mixed-model repeated measures. SETTING: University laboratory. PARTICIPANTS: Thirty physically active males with tight hamstrings and at least one latent MTrP on muscles innervated by the lumbosacral, sciatic, tibial and common peroneal nerves.