ARTICLE | doi:10.20944/preprints202209.0355.v1
Subject: Behavioral Sciences, Behavioral Neuroscience Keywords: Neck Muscle Vibration; Proprioception; Body Schema
Online: 23 September 2022 (03:45:37 CEST)
Upper limb control depends on accurate internal models of limb position relative to the head and neck, accurate sensory inputs, and accurate cortical processing. Transient alterations in neck afferent feedback induced by muscle vibration may impact upper limb proprioception. This research aimed to determine the effects of neck muscle vibration on upper limb proprioception using a novel elbow repositioning task (ERT). 26 right-handed participants aged 22.21 2.64 performed the ERT consisting of three target angles between 80-90 (T1), 90-100 (T2) and 100-110 (T3). Controls (CONT) (n=13, 6F) received 10 minutes of rest and the vibration group (VIB) (n=13, 6F) received 10 minutes of 60Hz vibration over the right sternocleidomastoid and left cervical extensor muscles. Task performance was reassessed following experimental manipulation. Significant time by group interactions occurred for T1: (F1,24 = 25.330, p < 0.001, p2 = 0.513) where CONT improved by 26.08% and VIB worsened by 134.27%, T2: (F1,24 = 16.157, p < 0.001, p2 = 0.402) where CONT improved by 20.39% and VIB worsened by 109.54%, and T3: (F1,24 = 21.923, p < 0.001, p2 = 0.447) where CONT improved by 37.11% and VIB worsened by 54.39%. Improvements in repositioning accuracy indicates improved proprioceptive ability with practice in controls. Decreased accuracy following vibration suggests that vibration altered proprioceptive inputs used to construct body schema, leading to inaccurate joint position sense and the observed changes in elbow repositioning accuracy.
ARTICLE | doi:10.20944/preprints201704.0034.v1
Subject: Medicine & Pharmacology, Sport Sciences & Therapy Keywords: latin dance, tai chi, knee proprioception
Online: 6 April 2017 (06:08:48 CEST)
To study the influence of Latin dance and Tai Chi on knee joint proprioception and balance. Method: All experiments were performed in the Beijing Normal University School of Physical Education and Sport Biomechanics Laboratory. An isokinetic test system (Biodex system 4, BS4) and a balance testing system (Biodex Balance System, BBS)from the United States Biodex medical system were used to test related indexes. Results: In the LOS test, the overall score of Latin group is much better than sedentary group. In the ASL test, Latin group have a better balance ability in anterior and posterior direction and overall score than sedentary group(p＜0.05); TAI CHI group have a better balance ability than sedentary group in anterior and posterior direction(p＜0.05)and right and left direction (p＜0.01). When the knee joint was at 15, 30, and 45degree positions, the Tai Chi exercise group was much better than sedentary group (P < 0.05), and the 45 degree position in the Tai Chi group was much better than that in the Latin dance group (P < 0.01).When the knee joint was at the 30 degree position, the quadriceps force sense was significantly better in the Tai Chi group than in the Latin dance and sedentary groups. In a test of the four angles, the hamstring force sense in the Tai Chi exercise group was obviously better than that in the sedentary group (P < 0.05); at the 15 degree position, the Tai Chi group was significantly better than the Latin group (P < 0.05); and at 30 degree position, the hamstring force sense of the Latin group was obviously better than that of the sedentary group (P < 0.05).
HYPOTHESIS | doi:10.20944/preprints202204.0144.v1
Subject: Biology, Physiology Keywords: reflex; proprioception; sensorimotor; muscle spindle; fascia; human
Online: 15 April 2022 (10:40:53 CEST)
Despite more than hundred years of research since Sir Sherrington’s studies on reflexes, his questions are still somehow unanswered. On what anatomical stage do the play of spinal reflex interaction take place? What are the physiological properties of this anatomical substrate? In this paper, we address these questions in light of the most advanced theory of motor control and the anatomical discoveries on the fascia that are changing how we think about control of action and perception. There are two sides of the problem: the neurological (reflex) connections that are at the base of movement, and the anatomical substrate that regulates and coordinates the movement. We recently advanced a hypothesis on how these two elements are connected and how they interplay. Here we further explain the concept of the somatic equilibrium point – SEP – and its central role in movement control and coordination. It is our belief that the concept of SEP explains how the neuro-mechanical control of movement is organized at peripheral level. At this level, intrafusal and extrafusal muscle fibres are combined in myofascial units, organized in anatomical directions. Myofascial units are closed systems whose behaviour can be affected by neural (voluntary) control or changes in external forces. SEPs represent the intrinsic equilibrium of the myofascial units, and are connected through the continuum of the fascia so that mechanical transfer of tension from segment to segment pre-adjust muscle fibers length and hence their excitation level. This is how coordination between segments is achieved. Finally, we suggest SEPs create the neurological representation of the referent configuration for action, and configurations are linked to the architecture of the fascial system.
REVIEW | doi:10.20944/preprints202202.0161.v2
Subject: Biology, Physiology Keywords: muscle spindle; proprioception; sensorimotor; fusimotor; signal processing; human
Online: 6 June 2022 (09:17:09 CEST)
Muscle spindles are encapsulated sensory organs found in most of our muscles. Prevalent models of sensorimotor control assume the role of spindles is to reliably encode limb posture and movement. Here, I argue that the traditional view of spindles is outdated. Spindle organs can be tuned by spinal γ motor neurons that receive top-down and peripheral input, including from cutaneous afferents. A new model is presented, viewing γ motor activity as an intermediate coordinate transformation that allows multimodal information to converge on spindles, creating flexible coordinate representations at the level of the peripheral nervous system. That is, I propose that spindles play a unique overarching role in the nervous system: that of a peripheral signal-processing device that flexibly facilitates sensorimotor performance, according to task characteristics. This role is compatible with previous findings and supported by recent studies with naturalistically active humans. Such studies have so far shown that spindle tuning enables the independent preparatory control of reflex muscle stiffness, the selective extraction of information during implicit motor adaptation, and for segmental stretch reflexes to operate in joint space. Incorporation of advanced signal-processing at the periphery may well prove a critical step in the evolution of sensorimotor control theories.
ARTICLE | doi:10.20944/preprints201911.0168.v1
Subject: Behavioral Sciences, Cognitive & Experimental Psychology Keywords: fine motor precision; vision; proprioception; sex differences; individual differences; personality
Online: 15 November 2019 (03:46:22 CET)
Previous studies have reported certain sex differences in motor performance precision. The aim of the present study was to analyse sex differences in fine motor precision performance for both hands in different tests conditions. 220 Spanish participants (ages: 12-95) performed fine motor tasks - tracing over the provided models – lines of 40 mm for both hands, two sensory conditions (PV – proprioceptive-visual; P – proprioceptive only) and three movement types (F – frontal, T – transversal and S - Sagittal). Differences in line length (the task focused on precision) were observed through MANOVA analysis for all test conditions, both sexes and different age groups. Sex differences in precision were observed in F and T movement types (statistically significance level and higher Cohens’ d was observed in condition with vision). No any statistically significant differences were observed in both hands and sensory conditions in sagittal type. Sex differences in fine motor precision were more frequently observed in the PV sensory condition in the frontal movement type and less in the sagittal one.
ARTICLE | doi:10.20944/preprints202007.0470.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: Posture control; low back pain; COP; proprioception; Recurrence Quantification Analysis; Vibrator
Online: 20 July 2020 (11:39:23 CEST)
Central nervous system (CNS) uses vision, vestibular, and somatosensory information to maintain body stability. Research has shown that there is more lumbar proprioception error among low back pain (LBP) individuals as compared to healthy people. In this study, two groups of 20 healthy people and 20 non-specific low back pain participants (LBP) took part in this investigation. This investigation focused on somatosensory sensors and in order to alter proprioception, a vibrator (frequency of 70Hz, amplitude of 0.5 mm) was placed on the soleus muscle area of each leg and two vibrators were placed bilaterally across the lower back muscles. Individuals, whose vision was occluded, were placed on two surfaces (foam and rigid) on force plate, and trunk angles were recorded simultaneously. Tests were performed in 8 separate trials; the independent variables were vibration (4 levels) and surface (2 levels) for within subjects and 2 groups (healthy and LBP) for between subjects (4×2×2). MANOVA and multi-factor ANOVA tests were done. Linear parameters for center of pressure (COP) (deviation of amplitude, deviation of velocity, phase plane portrait (PPP), and overall mean velocity) and nonlinear parameters for COP and trunk angle ((recurrence quantification analysis) RQA and Lyapunov exponents) were chosen as dependent variables. Results indicated that NSLBP individuals relied more on ankle proprioception for postural stability. Similarly, RQA parameters for the COP on both sides and for the trunk sagittal angle indicated more repeated patterns of movement among the LBP cohort. Analysis of short and long Lyapunov exponents showed that people with LBP caused no use of all joints in their bodies (non-flexible), are less stable than healthy subjects.