Many sand scorpions are faithful to burrows they dig, however, it is unknown how these animals get back home after hunting excursions. Of the many mechanisms of homing that exist, path integration (PI) is one of the more common tools used by arachnids. In PI, an animal integrates its distance and direction while leaving its home, enabling it to compute an approximate home-bound vector for the return trip. The objective of our study was to test whether scorpions use PI to return home under absolute darkness in the lab. We first allowed animals to establish burrows in homing arenas. Then, after they left their burrow, we recorded the scorpion’s location in the homing arena before we transferred it to the center of a testing arena. We used overhead IR cameras to record its movements in the testing arena. If scorpions exhibited PI, we predicted they would follow a vector in the test arena that approximated the same angle and distance from the capture point to their burrow in their home arena. However, under the conditions of this experiment, we found no evidence that scorpions moved along such home-bound vectors. We speculate that scorpions may need a reliable reference cue to accommodate path integration.

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.

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).

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.

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.

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.

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.

The characteristics of response to stressful situations depend on a complex of factors such as personality traits, emotional regulation, health state, features of the nervous system, motor functions and proprioception. In cases of disruption of the brain's dopamine system due to disease or chemotherapy, hormone discharge due to stress, changes in emotions and proprioception may occur. The aim of our study was to find the relationship of stress resilence in verbal test and individual differences performed in proprioceptive test in onco-patients, sportsmen and group of control; as well as to observe the differences between these groups in the verbal stress resistance and individual differences proprioceptive tests. The results showed that onco-patients were less resistant as per verbal stress resistance outcomes for a major part of variables compared to other groups. The sportsmen were superior in verbal Risk and Control dimensions compared to other groups; but less in Positive Affectiveness. The proprioceptive test perfomance revealed the only statistically significant difference in performance in the dimension related to Mood, showing more Pessimism in the sportsmen group, but more Optimism in the oncopatients at temperamental (or intrisinc) level. The obtained results can be used by psychologists, therapists, coach and healthcare when needed to attend the specific needs of public, being pateints or sportsmen, etc.

(1) Background: Within the scope of prevention studies, many researchers have indicated the need to enhance knee proprioception. Kinesiology tape is one product that claims to enhance proprioception, however, its use has not been well researched in the healthy population before. The aim of the study was to investigate if kinesiology tape application on the quadriceps muscle enhances proprioception. (2) Methods: Twelve healthy and physically active volunteers (M=7, F=5, mean age= 20.75 ± 2.14, mean BMI=22.25 ±2.34) participated in the study. With computerized, custom-built isokinetic dynamometer, we recorded perceived joint position angles (small and large angles). For force sense, we recorded maximum voluntary isometric contractions (MVIC) and differences in torques (Nm) via force matching tasks both with vision and without vision on left leg. The absolute errors for joint position sense measurements and for force matching tasks and differences in MVIC both in untaped and taped conditions for left legs of all subjects were recorded. (3) Results: Two-way repeated measures ANOVA revealed that no significant interaction existed among small and large angle groups in both the conditions nor any main condition effect was observed in both the groups. (p&gt;0.05). Similarly, no differences were accounted in force matching tasks between the taped and un-taped with vision and without vision (p=0.52 and 0.38 respectively.) Statistically insignificant increments were observed in mean torque post application. (p=0.67) (4) Conclusions: Present study suggests that immediate kinesiology tape application on quadriceps muscle offers no benefits on proprioception in terms of joint position sense and force sense hence other preventive measures to strengthen the proprioceptive system should be relied upon.

Background: The standard surgical approach to amputation has failed to evolve significantly over the past century. Consequently, standard amputations often fall short with regards to improving the quality-of-life (QoL) for patients. A modified amputation has been designed at both the transtibial (TTA) and transfemoral (TFA) level that incorporates agonist-antagonist myoneural interface (AMI) constructs to provide patients with a novel alternative to standard amputation. Here, we present the patient reported outcome measures (PROMs) amongst our lower extremity AMI amputees and demonstrate an overall significant improvement in their physical and mental wellbeing. Methods: Four PROMs surveys, 1) EQ-5D-3L, 2) Lower Extremity Functional Scale (LEFS), 3) PROMIS-57, 4) Short Form-36 (SF-36), and 5) Sickness Impact Profile (SIP), were administered to lower extremity AMI amputees pre-operatively (baseline) and at 6 weeks, 3 months, 6 months, 9 months, 12 months, 24 months, 36 months, and 48 months post-operatively between June 24th, 2018, and December 15th, 2022. The surveys were either administered during a clinic visit or emailed at the encounter timepoint. Study data was collected and managed using REDCap (Research Electronic Data Capture) electronic data capture tools hosted at Brigham and Women’s Hospital. Analyses of collated data were performed by fitting a linear mixed model using SAS version 9.4 (SAS Institute, Cary, NC). Results: The cohort’s baseline and 12-month post-operative responses were compared to determine score improvement. The cohort demonstrated a significantly improved EQ-5D-3L index value (p<0.0001) and EQ VAS (p<0.0001) at 12-months post-operatively (n=22) when compared to baseline (n=28). The LEFS score significantly improved at 12-months post-operatively compared to baseline (p<0.0001) with a mean of 59.04 ± 3.14 (SE) at 12-months and a mean of 31.96 ± 2.84 (SE) at baseline. AMI patients demonstrated significantly improved scores across PROMIS-57 domains at 12-months compared to baseline scores; the p-value was <0.0001 for all domains except for the Depression domain where p=0.0181. The health domain scores significantly improved from baseline to 12-months post-operation for all SF-36 domains. Lastly, the SIP indicated a significant decrease in overall dysfunction from baseline to 12-months post-operation (p<0.0001). Conclusions: Modified lower extremity amputation with AMI construction has the potential to provide amputees with increased quality-of-life when compared to the pre-operative state. However, further investigation is necessary to determine whether the patient reported outcome measures of the AMI amputee cohort are superior to those who receive a standard amputation.

The agonist-antagonist myoneural interface (AMI), a surgical method to reinnervate physiologically-relevant proprioceptive feedback for control of limb prostheses, has demonstrated the ability to provide natural afferent sensations for limb amputees when actuating their prostheses. Following an AMI surgery, one potential challenge is atrophy of the disused muscles, which would weaken the reinnervation efficacy of AMI. It is well known that electrical muscle stimulus (EMS) can reduce the muscle atrophy. In this study, we conducted an animal investigation to explore whether the EMS can significantly improve the electrophysiological performance of AMI. The AMI surgery was performed in 14 rats, in which the distal tendons of bilateral solei donors were connected and positioned on the surface of the left biceps femoris. Subsequently, the left tibial nerve and the common peroneus nerve were sutured onto the ends of the connected donor solei. Two stimulation electrodes were affixed onto the ends of the donor solei for EMS delivery. The AMI rats were randomly divided into two groups. One group regularly received the EMS treatment (designated as EMS_on) for eight weeks and another was no EMS (designated as EMS_off). Two physiological parameters, nerve conduction velocity (NCV) and motor unit number, were derived from the electrically evoked compound action potential (CAP) signals to assess the electrophysiological performance of AMI. Our experimental results demonstrated that the reinnervated muscles of the EMS_on group generated higher CAP signals in comparison to the EMS_off group. Both NCV and motor unit number were significantly elevated in the EMS_on group. Moreover, the EMS_on group displayed statistically higher CAP signals on the indirectly activated proprioceptive afferents than the EMS_off group. These findings may suggested that the EMS treatment would be promise in enhancing the electrophysiological performance and facilitating the reinnervation process of AMI.

Ankle sprains are the most frequently occurring musculoskeletal injuries among recreational athletes. Ankle support through bandages following the initial orthotic treatment might be beneficial for rehabilitation purposes. Since hardly any study has investigated the impact of bandages in the acute phase of ankle sprains, our study examined the immediate effects of wearing an ankle bandage on fine coordination, proprioception, and motor performance in subjects five weeks after an acute ankle injury. In total, 70 subjects with acute unilateral supination trauma were tested. All subjects completed several rating questionnaires and biomechanical investigations, including a fine coordination and proprioception test, single leg stances, the Y-Balance test and gait analysis. All biomechanical investigations were conducted for the subject's injured leg with and without a bandage (MalleoTrain® Bauerfeind AG) and the healthy leg. Subjects reported moderate to strong improvements in ankle stability and pain when wearing the bandage. Wearing the bandage significantly normalized subjects’ single leg stance performance, as well as the stance phase duration, and the vertical ground reaction forces during walking. However, the bandage did not have a clear effect on fine coordination and proprioception. Wearing a bandage in the acute phase of an ankle sprain may immediately improve motor performance, including standing and walking.