Narrow Results

Muscle kinematics and kinetics are nonlinearly encoded by proprioceptors, and the changes in muscle length and velocity are integrated into Ia afferent. Besides, proprioceptive signals from multiple muscles are probably mixed in afferent pathways, which all lead to difficulties in proprioceptive recognition for the cerebellum. In this study, the artificial neural networks, whose organizations are biologically based on the spinocerebellar tract and cerebellum, are utilized to decode the proprioceptive signals. Consistent with the controversy of the proprioceptive division in the dorsal spinocerebellar tract, the spinocerebellar tract networks incorporated two distinct inferences, (1) the centralized networks, which mixed Ia, II, and Ib and processed them together; (2) the decentralized networks, which processed Ia, II, and Ib afferents separately. The cerebellar networks were based on the Marr–Albus model to recognize the kinematic states. The networks were trained by a specific movement, and the trained networks were subsequently required to predict kinematic states of six movements. The results demonstrated that the centralized networks, which were more consistent with the physiological findings in recent years, had better recognition accuracy than the decentralized networks, and the networks were still effective even when proprioceptive afferents from multiple muscles were integrated.

In order to ascertain the utility of a 250 Hz NSD Powerball^® gyroscope in increasing the maximum grip force and muscular endurance of the forearm, ten adults without pathology in their upper limbs exercised one forearm with the device during a period of one month. We evaluated grip strength and forearm muscle endurance with a Jamar dynamometer both at the end of the month as well as after a resting period of one month. There was a tendency (not statistically significant p = 0.054), for the volunteers to increase their maximum grip strength. There was also highly significant increase in muscle endurance (p = 0.00001), a gain that remained slightly unchanged after the rest. Because the gyroscope generates random multidirectional forces to the forearm, the reactive muscle contraction is likely to stimulate more efficient neuromuscular contro of the wrist, a conclusion which our work appears to validate. The use of Powerball^® in forearm proprioception deficient patients is, therefore, justified.

Background: Proprioception and sensorimotor input are used to treat neurological and joint injuries. Following distal radius fractures (DRF) there is a temporary loss of proprioception that should be addressed. We created a protocol for evaluation, and a treatment plan following wrist surgery that is based on proprioceptive and sensorimotor input. We describe a series of patients undergoing surgery for DRF that were evaluated and treated with these protocols.

Methods: Both evaluation and treatment protocols included comprehensive sensorimotor procedures performed with eyes open and closed. These included Semmes- Weinstein, static and moving 2-point discrimination, vibration, temperature testing, Moberg pick-up- test, stereognosis and proprioception.

Results: A series of twelve patients was evaluated and treated with the protocol following surgical treatment for DRF. Patients demonstrated significant sensorimotor deficits, which improved utilizing the comprehensive sensorimotor treatment protocol.

Conclusions: Further study is necessary to validate the results of this pilot series. Use of proprioception and sensorimotor input may improve outcomes of rehabilitation following DRF.

Osteoarthritis (OA) is steadily becoming the most common cause of disability with advancing age. So, this study was aimed to prevent and rehabilitate the patient with such disability. Proprioception along with other deficits have been established with threat to the concerned joint. Hence, objective of the study was set to show the efficacy of proprioceptive training with conventional physiotherapy versus conventional physiotherapy. A Pre test- Post test single blind experimental study was designed with 44 patients having knee OA and randomly divided in two groups. Outcome measures were pain intensity on NRS, functional disability on Reduced WOMAC and joint position sense (JPS) error on Electronic Goniometer. Results between group comparisons showed significant improvement in pain intensity (p < 0.05), WOMAC score (p < 0.05) and JPS error (p < 0.05). However both the groups improved significantly but there was more significant improvement in group with proprioception intervention. Hence, it can be concluded that proprioceptive training should be included along with conventional physiotherapy in knee OA rehabilitation.

Virtual proprioception represents a novel means of developing cortical reorganization of alternative strategies for hemiparetic gait. Fundamentals of the device are motor control plasticity, aftereffect, and visual-based biofeedback. Two wireless three-dimensional (3D) microelectromechanical systems (MEMS) accelerometers are placed on the femur (upper leg) of both the affected and unaffected limbs above the lateral epicondyle next to the knee joint. The acceleration data from the two wireless 3D MEMS accelerometers are fed back to the user in real time by visual output from a portable laptop PC. Given the virtual proprioception feedback, the user can then adjust the original gait while walking to an improved alternative gait strategy. First, hemiparetic gait is comprehensively discussed. The inherent roles of proprioception with locomotion and issues with traumatic brain injury are considered. Then, the technology advance of accelerometers and gait analysis is detailed. Virtual proprioception is tested and evaluated, while demonstrating the capacity to improve disparities in hemiparetic gait during real time.

Background and aim: Fatigue of internal or external rotators of the glenohumeral may alter proprioception in the shoulder joint. Fatigue of shoulder muscles can affect the three-dimentional kinematics of the scapula, and may also alter the glenohumeral and scapular movement pattern, with changes in the scapulohumeral rhythm. Previous studies have shown that with arm elevation, there is a decreased upward rotation of the scapula as well as reduced posterior tilt and external rotation movements with shoulder rotator cuff muscle fatigue. Our aim is to examine the effect of internal rotator fatigue on the proprioception of glenohumeral and scapular active repositioning. Methods: Twenty young healthy subjects with an average age of 20 years were recruited. Each subject performed repetitive concentric exercise (internal rotation) to induce muscles fatigue, which was confirmed by a muscle strength testing using a hand-held dynamometer. Measurement of active repositioning with glenohumeral and scapula repositioning were examined before and after internal rotator fatigue via the three-dimensional (3D) electromagnetic motion analysis system. Results: Fatigue of internal rotators did not affect the glenohumeral and thoracoscapluar joint proprioception (P > 0.05). Conclusion: The findings showed that fatigue of shoulder internal rotators did not contribute to alteration in glenohumeral and scapular proprioception.

Proprioception while standing is important for the balance control, but the proprioception has not been investigated in the unconstrained standing conditions. The purpose of this study was to investigate the effects of age and gender on the thresholds of perception and muscle response in response to the support surface rotation. The experiment was designed so that the thresholds depend mainly on the proprioception, i.e., quasistatic condition (0.2^∘/s rotation of the platform) with eyes closed. Fifty-two healthy subjects (half young and half elderly) participated in this study. A platform was developed which can be rotated in four directions. Perception threshold angle was registered from subjects’ pressing a button. Muscle response threshold angle was determined as the earlier onset of EMG in lower limb muscles. Two standing conditions (feet together and natural stance) were tested. Repeated-measures ANOVA showed that both thresholds increased with age. Post hoc tests revealed (1) that the perception threshold was greater for women than men in the elderly and (2) both thresholds of the elderly were greater for the feet-together stance than natural stance. Inferior perception sensitivity of platform rotation in elderly women may be associated with inferior performance in cortical postural control and greater fall ratio compared to elderly men, which suggests the need of proprioception trainings.

The proprioceptive sense is a very important function for the body, and joint position error test (JPET) is commonly used to measure it. This study was to analyze the difference of proprioception in standing and sitting postures through the JPET. A total of 60 students (M/F, 12/48) in D University in Gyeongsangbuk-do, South Korea participated in this study. A JPET was performed with the subject’s eyes closed to assess the neck proprioception. The movement of the neck was measured in flexion, extension, and lateral flexion, and separately measured when sitting and standing. The difference in repositioning errors between sitting and standing postures was analyzed using paired $t$-test. There was a significant difference in repositioning errors between sitting and standing posture in neck extension. There was no significant difference in repositioning errors between sitting and standing posture in neck flexion and lateral flexion. In conclusion, in a sitting posture, posterior neck muscles are used more than in the standing posture, which may negatively affect the proprioceptive accuracy of the neck and may also increase the neck repositioning errors.

The aim of this study is to investigate the effect of knee extensors fatigue on joint position sense. Fifteen healthy participants, all males, with no history of previous musculoskeletal lesions were recruited. Evaluation of the knee joint position sense and the muscle fatigue protocol had been performed using an isokinetic dynamometer. Fatigue was considered when the maximum torque was reduced by 50%. The joint position sense was analyzed by the absolute error and the variable error. The paired t-test was used to compare the mean in pre and during muscle fatigue conditions. The level of significance was 5%. Absolute and variable errors were not significantly affected by muscle fatigue. Knee joint position sense does not seem to be affected by fatigue of knee joint extensors.

The objective of this research was to evaluate the effects of biofeedback equipment with a tilt sensor and a neck correction exercise program on balance control ability, proprioception, and craniovertebral angle (CVA) in young adults. Ten students (M/F, 7/3) aged 20–30 years attending Sunmoon University in Asan-si, South Korea, participated in this study. All subjects participated in three sessions. These sessions consisted of a biofeedback session with a tilt sensor, followed by an exercise session, and a combined session involving biofeedback equipment with a tilt sensor and exercise. Each session takes 30min. The sessions were conducted with a one-day interval between each one. Before the start of the experiment, physical characteristics were measured, and proprioception, balance control ability, and CVA were evaluated. The exercise program significantly improved the stability index (SI) in the eyes-closed state. The biofeedback program resulted in improvement in left rotation, and the CVA was significantly improved after all exercise sessions. In conclusion, a neck correction exercise program that actively moves muscles may have a potential positive impact on balance control ability. Biofeedback equipment might aid in enhancing proprioception by preventing forward head posture (FHP).

Background: During the process of aerobic exercise, there are a lot of jumping and split movements, which can easily cause anterior cruciate ligament (ACL) injury in the knee joint. After undergoing ACL reconstruction (ACLR) surgery, postoperative recovery is crucial. Currently, many methods have been applied, but research on water exercise is still limited. Purpose: This paper aims to understand the role of water exercise in the recovery of athletic ability after ACLR and provide guidance for athletes’ postoperative rehabilitation. Methods: Forty athletes with ACL injuries caused by aerobics practice or competition and undergoing surgery were randomly assigned to either group A or group B. The former received six weeks of a conventional postoperative recovery program, and the latter received six weeks of a water exercise postoperative recovery program. Knee joint range of motion (ROM), swelling value, visual analog scale (VAS) score, knee joint function score, and passive angle reproduction (PAR) were measured before and after the experiment. Results: After six weeks of recovery, the knee ROM was $127.84\pm 9.12^{\circ }$, the swelling value was $0.92\pm 0.53$cm, the VAS score was $1.86\pm 0.21$, the Lysholm score was $88.67\pm 5.62$, and the International Knee Documentation Committee (IKDC) score was $83.56\pm 13.64$ in group B, which were significantly lower than those before recovery and those in group A ($p<0.01$). After recovery, the PAR of the affected side was still different from that of the healthy side in the two groups ($p<0.01$), but the PAR of group B was better than that of group A ($p<0.01$). Conclusion: Compared to the conventional program, the water exercise-based postoperative recovery program demonstrates better performance in improving knee joint ROM, functionality, and proprioception, and can be used for practical post-ACLR rehabilitation.

A method for synergistic integration of multimodal sensor data is proposed in this paper. This method is based on two aspects of the integration process: (1) achieving synergistic integration of two or more sensory modalities, and (2) fusing the various information streams at particular moments during processing. Inspired by psychophysical experiments, we propose a self-supervised learning method for achieving synergy with combined representations. Evidence from temporal registration and binding experiments indicates that different cues are processed individually at specific time intervals. Therefore, an event-based temporal co-occurrence principle is proposed for the integration process. This integration method was applied to a mobile robot exploring unfamiliar environments. Simulations showed that integration enhanced route recognition with many perceptual similarities; moreover, they indicate that a perceptual hierarchy of knowledge about instant movement contributes significantly to short-term navigation, but that visual perceptions have bigger impact over longer intervals.

Most previous studies on multisensory integration concern mandatory integration. Moreover, no study has evaluated the effect of modality training on the result of integration. The purpose of this study is to evaluate the effect of training on visual-proprioceptive integration; i.e., we investigate the effect of proprioceptive modality training on the hand location estimation, when visual feedback exists. To achieve this goal, the effect of visual uncertainty on the estimation of hand position in visual-proprioceptive integration is studied in two groups: trained proprioception and untrained proprioception. The visual uncertainty is provided by an unpredictable spatial shift between visual and proprioceptive sensory feedbacks. The experiment was performed on nine subjects with trained proprioception and 11 subjects without proprioception training. The experiment had three phases: "familiarization", to draw participant's attention to a modality, "proprioception test", to estimate the hand position using only proprioception, and "vision-proprioception test", to investigate the effect of the visual uncertainty (bias) on hand position estimation. Our results indicate that: (i) modality training increases the subject reliance on the proprioceptive sensory information (i.e., bias decrement in sensory integration); and (ii) increasing the discrepancy between the modalities leads to more uncertainty (i.e., variance) in the estimation of hand position, but the variance of the final estimate is less than the variance of the proprioceptive estimate. This result confirms the theory that both senses contribute to the multisensory perception and in contrast to some studies, the dominant sense does not fully override the non-dominant one in the range of applied shift between the sensory sources.

Humans perceive the surrounding world by integration of information through different sensory modalities. Earlier models of multisensory integration rely mainly on traditional Bayesian and causal Bayesian inferences for single causal (source) and two causal (for two senses such as visual and auditory systems), respectively. In this paper a new recurrent neural model is presented for integration of visual and proprioceptive information. This model is based on population coding which is able to mimic multisensory integration of neural centers in the human brain. The simulation results agree with those achieved by casual Bayesian inference. The model can also simulate the sensory training process of visual and proprioceptive information in human. Training process in multisensory integration is a point with less attention in the literature before. The effect of proprioceptive training on multisensory perception was investigated through a set of experiments in our previous study. The current study, evaluates the effect of both modalities, i.e., visual and proprioceptive training and compares them with each other through a set of new experiments. In these experiments, the subject was asked to move his/her hand in a circle and estimate its position. The experiments were performed on eight subjects with proprioception training and eight subjects with visual training. Results of the experiments show three important points: (1) visual learning rate is significantly more than that of proprioception; (2) means of visual and proprioceptive errors are decreased by training but statistical analysis shows that this decrement is significant for proprioceptive error and non-significant for visual error, and (3) visual errors in training phase even in the beginning of it, is much less than errors of the main test stage because in the main test, the subject has to focus on two senses. The results of the experiments in this paper is in agreement with the results of the neural model simulation.

Our ability to properly move and react in different situations is largely dependent on our perception of our limbs’ position. At least three sources — vision, proprioception, and internal forward models (FMs) — seem to contribute to this perception. To the best of our knowledge, the effect of each source has not been studied individually. Specifically, role of FM has been ignored in some previous studies. We hypothesized that FM has a critical role in subjects’ perception which needs to be considered in the relevant studies to obtain more reliable results. Therefore, we designed an experiment with the goal of investigating FM and proprioception role in subjects’ perception of their hand’s position. Three groups of subjects were recruited in the study. Based on the experiment design, it was supposed that subjects in different groups relied on proprioception, FM, and both of them for estimating their unseen hand’s position. Comparing the results of three groups revealed significant difference between their estimation’ errors. FM provided minimum estimation error, while proprioception had a bias error in the tested region. Integrating proprioception with FM decreased this error. Integration of two Gaussian functions, fitted to the error distribution of FM and proprioception groups, was simulated and created a mean error value almost similar to the experimental observation. These results suggest that FM role needs to be considered when studying the perceived position of the limbs. This can lead to gain better insights into the mechanisms underlying the perception of our limbs’ position which might have potential clinical and rehabilitation applications, e.g., in the postural control of elderly which are at high risk of falls and injury because of deterioration of their perception with age.

This paper proposes a novel central pattern generator (CPG) model with proprioceptive mechanism and the dynamic connectivity mechanism. It not only contains the sensory information of the environment but also contains the information of the actuators and automatically tunes the parameters of CPG corresponding to the actuators information and inner sensory information. The position of the joints linked directly with the output of CPG is introduced to the CPG to find its proprioceptive system, spontaneously making the robot realize the actuator working status, further changing the CPG output to fit the change and decrease the influence of the problematic joints or actuators on the robot being controlled. So the damage would be avoided and self-protection is implemented. Its application on the locomotion control of a quadruped robot demonstrates the effectiveness of the proposed approach.