Vestibular Influence on Vertebrate Skeletal Symmetry and Body Shape

Vestibular endorgans in the vertebrate inner ear form the principal sensors for head orientation and motion in space. Following the evolutionary appearance of these organs in pre-vertebrate ancestors, specific sensory epithelial patches, such as the utricle, which is sensitive to linear acceleration and orientation of the head with respect to earth’s gravity, have become particularly important for constant postural stabilization. This influence operates through descending neuronal populations with evolutionarily conserved hindbrain origins that directly and indirectly control spinal motoneurons of axial and limb muscles. During embryogenesis and early post-embryonic periods, bilateral otolith signals contribute to the formation of symmetric skeletal elements through a balanced activation of axial muscles. This role has been validated by removal of otolith signals on one side during a specific developmental period in Xenopus laevis tadpoles. This intervention causes severe scoliotic deformations that remain permanent and extend into adulthood. Accordingly, the functional influence of weight-bearing otoconia, likely on utricular hair cells and resultant afferent discharge, represents a mechanism to ensure a symmetric muscle tonus essential for establishing a normal body shape. Such an impact is presumably occurring within a critical period that is curtailed by the functional completion of central vestibulo-motor circuits and by the modifiability of skeletal elements before ossification of the bones. Thus, bilateral otolith organs and their associated sensitivity to head orientation and linear accelerations are not only indispensable for real time postural stabilization during motion in space but also serve as a guidance for the ontogenetic establishment of a symmetric body.

Formation of a Novel Supraspinal-Spinal Connectome that Relearns the Same Motor Task after Complete Paralysis

Electrical spinal cord stimulation enables paraplegic patients to regain voluntary leg movement. This treatment was only intended to engage local spinal networks to facilitate basic standing and postural stabilization without supraspinal input. Therefore the mechanism(s) enabling voluntary movement are unknown. Here we developed the first conditioned behavioral paradigm in rats for studying the recovery of voluntary movement after a paralyzing spinal injury and characterize the recovered neural connection. Rats were trained to kick their right hindlimb in response to an auditory cue. The rats then received a mid-thoracic spinal cord injury, causing hindlimb paralysis. After which, the rats were treated with spinal electro-neuromodulation across the lumbosacral enlargement. Two months after injury, spinal electro-neuromodulation enabled the rats to recover the trained behavior. Stopping or starting the electro-neuromodulation immediately abolished or facilitated recovery. Quipazine (nonspecific 5HT agonist) selectively abolished this recovered voluntary movement. Our work demonstrates a previously unknown highly specific reorganization phenomenon that can functionally reconnect the most distant neural structures. The interference of quipazine suggests the recovery mechanisms differ from those traditionally studied using electro-neuromodulation to recover postural and locomotor functions, and the speed of recovery of this conditioned behavior when electro-neuromodulation was applied proves these mechanisms are engaged within seconds of treatment.

Agreement of Ultra-Short-Term Heart Rate Variability Recordings During Overseas Training Camps in Under-20 National Futsal Players

Background: Monitoring the daily change in resting heart rate variability (HRV) can provide information regarding training adaptation and recovery status of the autonomic nervous system (ANS) during training camps. However, it remains unclear whether postural stabilization is essential for valid and reliable ultra-short-term (HRVUST) recordings in short-term overseas training camps.Design: Observational and longitudinal study.Purpose: This study aimed to investigate ultra-short-term heart rate variability recordings under stabilization or post-stabilization periods in four overseas training camps.Participant: Twenty-seven U-20 male national team futsal players voluntarily participated in this study.Method: Resting HRV was evaluated for 10 min during the early morning of each training camp. The natural logarithm of the root mean square of successive normal-to-normal interval differences (LnRMSSD) was used for comparisons. Time segments of HRV were divided into two periods with three measures within each: (1) the first 30-s (1st_30 s LnRMSSD), the first 60-s (1st_60 s LnRMSSD), and the 5-min standard (1st_5 min LnRMSSD) during stabilization; (2) the first 30-s (2nd_30 s LnRMSSD), the first 60-s (2nd_60 s LnRMSSD), and the 5-min standard (2nd_5 min LnRMSSD) after stabilization.Result: The results demonstrated trivial to small ES (−0.03; 0.46), very large to nearly perfect ICC (0.76; 0.98), and narrow range of SEM (0.06; 0.31) when all time segments of HRVUST were compared to the 1st_5 min and 2nd_5 min HRV. Furthermore, the magnitude of the correlation coefficients ranged from very high to nearly perfect for all the time segments (r = 0.83; 0.97). The HRVUST posted excellent agreement in all time segments (bias = −0.05; 0.12) with/without postural stabilization. Trivial to small levels of effect size in all time segments of LnRMSSDmean (0.02; 0.41 ES) and LnRMSSDcv (−0.49; −0.02 ES) across overseas training camps was identified.Conclusion: The first 30 or 60-s LnRMSSD recordings can be used to evaluate daily cardiac-autonomic function during overseas training camps in futsal players. The process for stabilization seems to be unnecessary for measuring the morning resting LnRMSSD in overseas training camps among young adult futsal players.

Effects of a 6-week core stabilization training program on dynamic balance and trunk stabilization endurance of horse riders

The purpose of this study was to examine the effectiveness of a 6-week core stabilization training program (CSTP) in improving dynamic balance and back-extensor endurance of horse riders; and develop a measurement tool in assessing the dynamic postural stabilization endurance for horse riders. Twelve male horse riders (age: 23.58 ± 1.93 years; height: 165.09 ± 4.60 cm; weight: 56.53 ± 4.75 kg; experience in horse racing: 1.75 ± 0.34 years) completed 12 training sessions in 6 weeks. Subjects performed the CSTP with two progressions. CSTP started with the basic consciousness activation exercises, and then eliminated visual feedback in dynamic balance task on unstable surfaces and finished with switching the center of gravity. Moderate-to-large difference was demonstrated in the Y-Balance test scores for right leg (102.81 ± 8.32 vs 106.471 ± 4.35 cm, d = 0.55, 95% CL 0.00 to 1.08) and left leg (102.04 ± 3.20 vs 106.29 ± 3.62 cm, d = 1.25, 95% CL 0.41 to 2.05) following 6 weeks CSTP. However, trivial to small differences was reported between left and right leg in pre (d = 0.12, 95% CL − 0.49 to 0.73) and post 6-week CSTP (d = 0.04, 95% CL − 0.69 to 0.78). Biering–Sørensen test (BST) shows largely greater performance after 6-week CSTP (98.3 ± 30.1 vs 131.8 ± 19.0 s, d = 1.33, 95% CL 0.54–2.09). A novel measurement, Swiss ball four-point kneeling test was shown to be correlated with the change in BST (r = 0.633).

Ventral hernia from routine repairs to abdominal wall reconstruction: our initial experience

Background: Loss of continuity of abdominal wall significantly affects the functions of protection of viscera, postural stabilization, and maintenance of intra-abdominal pressure. The newer understanding of abdominal wall reconstruction (AWR) aims at restoring abdominal wall anatomy and function, instead of simply patching the defect. We want to showcase the changing trends and results in hernia repair at a Medical Institution.Methods: This is an observational retrospective study conducted in RRMCH, Bengaluru from July 2018-2019 including all patients with ventral hernia undergoing the specified hernia repairs.Results: A total of 54 patients with ventral hernias undergoing routine hernia repairs/AWR surgeries were retrospectively analysed. The overall mean age was 46.62±12.44 year. Majority subjects were females (n=37; 68.5%), and overweight (Mean BMI=28.07±3.01/m2). 14 patients (25.92%), all males, had history of tobacco consumption. There were 38 (70.37%) primary ventral hernias and 7 recurrent hernias. Overall mean defect size was 10.2±0.4 cm. Most frequently performed was open retro rectus Hernioplasty (n=18; 33.33%), followed by open Preperitoneal Hernioplasty (n=17; 31.48%), laparoscopic intraperitoneal onlay mesh (IPOM) (n=16; 29.62%) and open transversus abdominis release (TAR) (n=3; 5.5%). On statistical analysis, it was found that Open repairs had higher post-operative pain (p=0.0005), longer hospitalization (p=0.0002) and higher incidence of surgical site events (p=0.0134) when compared to Laparoscopic repairs.Conclusion: As known already, minimally invasive techniques of hernia surgeries are shown to have acceptable outcomes when compared to radical open surgeries. Newer techniques of AWR are being employed to routine cases in larger numbers, and not just for complex reconstruction, at most centres with acceptable outcomes.

A clinical pilot study on posture stabilization via light contact with cane-type companion robot

In this paper, toward robotic gait assistance, we investigate the feasibility of a cane-type assistive mobile robot accompanying the user autonomously through a clinical pilot experiment. As widely known, gait ability is important for all people to keep their quality of life. However, for people having weakened lower limbs such as elderly people, their postural sway during walking could be insuppressible and cause falling. To support the gait motion of elderly people, our group has been developing a series of hand-holding cane robots named Intelligent Cane. Such assistive robots are expected to remove barriers to the independent lives of elderly people. Recently, we have focused on the potential of a companion robot that follows the user ahead and can be touched or grasped for bracing whenever the user needs it. In order to demonstrate proof of our concept through an experiment with a motion capture system, we propose a user companion strategy that enables our cane robot to keep a constant relative distance between the robot and the user walking on a treadmill. We evaluate the accuracy of the user companion in an experiment where a user walks on a treadmill. Then, we conduct a clinical experiment with three healthy subjects walking on with the treadmill with our cane robot as a pilot study. Through the clinical experiment, we evaluate a postural stabilization effect of physical interaction with the robot and discuss the feasibility of our robotic gait assistance methodology.