The detection of sensory change is important for survival. A change-detection system requires a comparison with the past status. Therefore, the system does not only rely on the peripheral stimulus but also reflects the magnitude of deviance between a past sensory status and new sensory inputs and the accumulation of sensory history prior to the change. In this review, recent progress made in the study of human change-detection systems using electroencephalography and magnetoencephalography has been described. We have also discussed the possibility that an activity consistent with the simple onset paradigm, which has been used in many studies, may be involved in the change-detection system. As change-detection-related activity represents a preattentive automatic process with good reproducibility, it may be considered useful for clinical assessment.

Cast immobilization is known to induce mechanical hypersensitivity, which disturbs rehabilitation. Some studies suggested that central neuronal sensitization may contribute to immobilizationinduced hypersensitivity. However, there is no research in eff ective treatment for immobilizationinduced hypersensitivity so far. We suggest that the lack of sensory input to peripheral tissue due to immobilization might induce changes to the nervous system, and cause immobilizationinduced hypersensitivity. Therefore, to prevent immobilization-induced hypersensitivity, sensory input should be delivered from peripheral tissue. We proposal the vibration therapy as the sensory input during immobilization: it has been reported that vibration therapy can reduce various types of pain. However, it is unclear whether vibration therapy reduce immobilization-induced hypersensitivity. To investigate the preventive and therapeutic effects of vibration therapy on immobilization-induced hypersensitivity, rats were immobilized for 8 weeks and divided randomly into 2 immobilization plus vibration groups (Im+Vib1 and Im+Vib2). Im+Vib1 group, for which vibration therapy was initiated immediately after the onset of immobilization, and Im+Vib2, for which vibration therapy was initiated 4 weeks after the onset of immobilization. To investigate central sensitization, calcitonin gene-related peptide (CGRP) expression in the spinal cord and dorsal root ganglion (DRG) was analyzed. As a result, immobilization-induced hypersensitivity was inhibited in the Im+Vib1 group but not in the Im+Vib2 group. Central sensitization, which was indicated by increases in CGRP expression in the spinal cord and the size of the area of CGRPpositive neurons in the DRG, was inhibited in only the Im+Vib1 group. Vibration therapy might be an effective technique to supplement the loss of sensory input and to inhibit hypersensitivity. These data suggest that initiation of vibration therapy in the early phase of immobilization may inhibit the development of immobilization-induced hypersensitivity.

Although AT disorders do not typically become severe, they occur frequently and are considered to be one of the disorders that are difficult to manage. Recently, several effective treatment methods were reported; however, there are currently no eff ective methods to prevent this disorder. The reason for this could be that the mechanism of the disorder itself is not completely understood. This is most likely why the incidence of AT disorders is very high and why preventive methods are not well-established. In recent years, attempts have been made to elucidate the mechanism for the occurrence of AT disorders based on past research, with much attention to the twisted structure of the AT as a cause. There are numerous studies from the past several decades concerning the twisted structure of the AT. Several studies have unanimously reported that ATs are composed of an insertion tendon where the medial head of the gastrocnemius, lateral head of the gastrocnemius, and the soleus muscle insert, exhibit twisted structures, and are all twisted in the lateral direction without exception. But, a consensus has yet to be reached in terms of the extent of twisting. In this paper, we introduce the anatomical studies that we have carried out in recent years as a basic research for the elucidation of the generation mechanism.

Musculoskeletal simulation models that estimate the muscle tension force are widely used to explain muscle and joint function during motion. This model has an advantage to calculate muscle tension force and joint contact forces during motion with noninvasive gait measurement. The musculoskeletal simulation model-based analysis enables easy access for researchers to predict the joint contact force during human motion and determine the risk of osteoarthritis. It can also clarify the direct relationship between muscle tension force and joint angular acceleration or acceleration of the center of mass. Determination of which muscle supports body weight or controls joint motion will provide basic knowledge for physical therapists. In addition, determination of how patients maintain kinematic equilibrium during motion can help understand the patient-specific compensated strategy and decide on an appropriate intervention. This paper focuses on the introduction of the basic concept of musculoskeletal simulation analysis and applications of the result of previous studies to motion analysis in physical therapy.

It is important to evaluate the efficacy of physical therapy using brain mapping technologies.Magnetoencephalography (MEG) is one of the powerful noninvasive tool for examining the temporal and spatial aspects of motor and sensory processing in the brain. In this paper, MEG responses elicited by voluntary movement and innocuous somesthetic stimuli were reviewed. 1) Movement related cortical fields were enhanced by voluntary bilateral hand movement in a patient with mild hemiplegia. 2) Clear sensorimotor responses were detected by imaging motor tasks without any body movement. 3) MEG can detect a quick detection system of abrupt changes in the sensory environment (change-related response), which is an index of evaluating sensory memory process. 4) Somesthetic responses were inhibited by inserting a weak leading stimulus, which indicates the presence of an inhibitory process beyond a simple reduction in response-generating activities. These findings will be helpful in further evaluation for physical therapy of the central nervous system.

We aimed to investigate the role of loading intensity and volume in neuromuscular electrical stimulation (ES)-induced skeletal muscle hypertrophy in rats. Male Wistar rats (8－9 wk, n=35) were assigned randomly to the following groups. Experimental (EX) 1: 60%FAIL (n=6), 60% of maximum isometric torque (MIT) to task failure at supramaximal voltage (45 V); 30%VM (n=6), 30% of MIT with volume-matched to 60%FAIL; 15%VM (n=6), 15% of MIT with volume-matched to 60%FAIL. EX2: 30%FAIL (n=6), 30% of MIT to task failure at supramaximal voltage; 30%1/4V (n=6), 30% of MIT with 1/4 volume of 30%FAIL; 30%1/8V (n=5), 30% of MIT with 1/8 volume of 30%FAIL. For ES training, left plantar fl exor muscles were stimulated via a surface electrode (0.5 ms pulse, 50 Hz, 2 s on/4 s off ) every other day for 3 weeks. The contralateral right muscles served as control (non-ES). In EX1, the gastrocnemius muscle weight normalized to body weight (MW/BW) in ES side was increased above non-ES side by 10.9±1.3%, 6.6±1.1%, and 3.5±0.5% in 60%FAIL, 30%VM, and 15%VM groups, respectively, with a greater gain in 60%FAIL than 30%VM and 15%VM. In EX2, MW/BW was higher in ES side than in non-ES side both in 30%FAIL (6.1±1.3%) and 30%1/4V (6.8±1.2%) but not in 30%1/8V groups, with no difference between groups. Moreover, the extent of muscle hypertrophy was higher in 60%FAIL group than in 30%FAIL group, despite the loading volume of 60%FAIL group was about half of that in 30%FAIL group. There was no change in myofi brillar protein concentration between ES and non-ES side in all groups examined. These data suggest that the higher loading intensity, rather than the loading volume, is recommended to maximize muscle hypertrophy with ES training.

Objective: Detailed mechanisms underlying neural control of bilateral ankles during repetitive ankle movements are still unknown. The aim of the present study was to investigate how the neural properties were different between in-phase and antiphase repetitive bilateral ankle movements. Methods: Fifteen healthy young adults participated in the study. The participants performed in-phase (move the bilateral ankle simultaneously) and anti-phase (move the bilateral ankle alternately) repetitive ankle movements tasks in randomized order. Single or paired TMS (ISI=2ms, for measuring short intracortical inhibition: SICI) was delivered at hotspot which both motor-evoked potential (MEP) of the right tibialis anterior muscle (TA) and the soleus muscle (SOL) were detected in left primary motor cortex, when EMG of right TA were on-set and off-set condition during ankle movements tasks. Results: In off-set condition, The MEP amplitude of the SOL during antiphase task was significantly larger than that during inphase task. There were no significant diff erences between tasks in the MEP amplitude of the SOL at on-set condition and the TA in both conditions, and SICI in both conditions of TA and SOL. Conclusion: Neural property of the repetitive movement was prominent during antiphase movement of the ankles. These results suggest that the properties of phase during repetitive movement of the bilateral lower limbs might be considered in rehabilitative interventions.

Purpose: The purpose of this study was to investigate the gender characteristics on scapular kinematics during shoulder three planes of elevation with and without external loading. Methods: Nine healthy men and 10 healthy women participated in this study. The subjects performed shoulder flexion, scapular plane elevation, and abduction with and without loading. An electromagnetic motion capture system was used to analyze scapular orientation, and change in the scapular orientation from the resting position was calculated. Results: Scapular posterior tilt with loading significantly decreased compared to that without loading for shoulder flexion and abduction in men. There was no change in the scapular orientation with or without loading in women. Women had lower upward rotation and posterior tilt angle with or without loading. Discussion: This study revealed the gender differences in scapular kinematics during shoulder elevation with and without loading. In women, the scapular motion was less, and had muscle activity characteristic which possibility explains why there was no change in the scapular orientation with loading.

The aim of this study was to examine the effect of hip joint angle on muscle stiffness of the adductor longus（AL） during hip fl xion task. Ten healthy young adults（men）were recruited for this study. To investigate the effect of hip joint angle on muscle stiffness, shear modulus of AL was measured during the isometric hip flexion tasks at 0%, 25%, 50%, 75%, and 100% of maximum voluntary contractions of the hip flexors for each hip flexion joint angle of －20°, 0°, 20°, 40°, 60°, and 80° using ultrasound shear-wave elastography. The changes in muscle stiffness of AL with the hip flexion tasks were different between hip joint angles. During hip flexion, a significant interaction of hip joint angle and contraction intensity on the muscle stiffness of AL was found (P < 0.001). Active stiffness normalized to the hip flexion maximal torque at hip flexion angles of －20°, 0° and 20° were significantly higher than at hip angles of 40°, 60° and 80°（P < 0.05）. These results demonstrate that muscle stiffness of AL with hip flexion were influenced by the hip joint angle, and it was higher at the hip angles of －20° to 20°. The findings suggest that the mechanical stress of AL with hip flexion might be higher in the extended region and shallow flexion region of hip joint range motion.