During rehabilitation for Parkinson's disease, physical therapists often utilize visual or auditory guidance to facilitate movement in patients. However, the neural mechanism involved in these procedures is unclear. Goldberg (1985) proposed an internal and external loop of motor control that is supported by much physiological evidence from primate research. However, brain imaging studies are insufficient to verify this hypothesis. In this study, we scanned eleven right-handed healthy subjects by functional magnetic resonance imaging while they performed (1) self-initiated finger-to-thumb opposition movements once every second and (2) identical movements externally triggered by the sound of a metronome. With the externally triggered movements, activation of the cerebellum and temporal gyrus was observed to decrease, and that of the premotor cortex and parietal cortex was observed to increase. We concluded that the cerebellum and supplementary motor area constitute a part of the internal loop, while the premotor cortex and parietal cortex are involved in the external loop.
The purpose of this study was to observe the influence of duration time of isometric contraction on blood pressure of healthy young males. The blood pressure of 16 normal young males was measured before and after 3 sessions of push-up exercise. All subjects did push-up and hold for 5 seconds (T5), 10 seconds (T10) and 15 seconds (T15), respectively. The results indicate that only the systolic pressure was increased irrespective of the isometric contraction exercise time, and no significant difference was found in the systolic pressures among the isometric contraction exercise times. Also no significant difference was found in the change of pulse systolic pressure between the T5 and T10 groups, but there was a remarkable difference between both the group T5 and T15, and the T10 and T15 groups. The present results reveal that isometric contraction exercise increases the systolic pressure and that the effect of the cushion reflex on adjustment of blood pressure lasts from 10 to 15 seconds.
We investigated the muscle activity of the shoulder joint during single-leg standing three types of ambulatory aid, T-shaped cane (T-cane), Quadripod cane (Q-cane) and Lofstrand crutch (L-crutch) in which were used. The left leg of eight healthy volunteers was assumed to be an affected leg. All participants were asked to keep 20% of the weight-bearing load on the ambulatory aid and the electromyography (EMG) was recorded. Results of the analysis of variance followed by Fisher's PLSD post hoc test reveal that EMG values of the medial and posterior part of the deltoid muscle were significantly related to the three types of ambulatory aid, but the anterior part of the deltoid was not. EMG values of the biceps brachii, triceps brachii, and latissimus dorsi were significantly larger in T-cane and Q-cane users than in L-crutch users, and EMG of the pectoralis major was significantly larger in Q-cane users than in L-crutch users. These results permit us to select an appropriate ambulatory aid for patients.
The purpose of this study was to investigate the influence of different angles of knee joint on the activation level of agonist and antagonist muscles from electromyographic activities and torque measurement during maximum isometric efforts. Electromyographic activities and isometric torque measurements were performed on 10 healthy subjects at 30, 60 and 90 of knee joint flexion with the hip fixed at 80 of flexion. To quantify the antagonist muscle activity, we normalized its electromyographic value at each joint angle with respect to its electromyographic value at the same angle acting as an agonist at maximal effort. The results indicate that the greatest maximal voluntary isometric contraction torque of the quadriceps occurred during knee extension at 60 of knee flexion. Co-activation of quadriceps and hamstrings at certain angles can help to maintain the stability of the knee joint. However, no significant relationship of maximal voluntary isometric contraction electromyography and maximal voluntary isometric contraction torque of quadriceps were found in our study. Further investigation of the torque and electromyographic relationship using combinations of different hip and knee angles are suggested.
The objective of this study was to analyze the effects of an 8-week home exercise program with and without electromyographic biofeedback on the relative activations of the vastus medialis obliquus and vastus lateralis using electromyographic measurement in patients with patellofemoral pain syndrome. Twenty-six subjects were randomly allocated into "exercise only" (Group 1) and "electromyographic biofeedback + exercise" (Group 2) groups. Both groups performed the same exercise program and Group 2 received electromyographic biofeedback from a system that provided real-time information on the relative activations of the vastus medialis obliquus and vastus lateralis during the exercises. The intensity of the knee pain was also recorded on a pain severity scale, respectively. These parameters were measured before and after the 8-week home exercise program. The results show that Group 1 had insignificant changes in the vastus medialis obliquus/vastus lateralis electromyographic ratio (p=0.355), whereas Group 2 had significantly a higher vastus medialis obliquus/vastus lateralis electromyographic ratio (p=0.017) when performing normal activities throughout a 6-hour assessment period. The present results reveal that the incorporation of electromyographic biofeedback into a home exercise program could facilitate the activation of the vastus medialis obliquus muscle, such that the muscle could be preferentially recruited during daily activities.
The satisfaction of patients after total hip arthroplasty (THA) was evaluated. At the same time, the physical function was evaluated in six hip joint groups of muscles as hip function recovery criteria of the Japanese Orthopaedics Association (JOA) Hip score, and also health-related quality of life (QOL) was evaluated by SF-36. The items that influenced a global satisfaction were related to the operation but not to activities, e.g., hobbies. The group of patients with high satisfaction of treatment showed higher scores for gait ability and activities of daily living (ADL) than the group of patients with poor satisfaction aid. The degree of role accomplishment at home was one of the important factors to affecting QOL. Development of rehabilitation and medical treatment in a long-term viewpoint is important for social participation of the patient. The satisfaction of the patient was related not only to the local hip disorder but also many other factors including psychological items. Therefore, the global evaluation of total outcomes of the medical service should be done include the degree of satisfaction of patients.
We examined the effects of fluid and food intake on cardiopulmonary status during cardiopulmonary exercise testing (CPX). Twelve young men fasted for 12 hours, followed by CPX under three experimental conditions: 1) continuation of fasting; 2) ingestion of 420 ml of water; and 3) ingestion of 420 g of jelly. For the second and third experimental conditions a 30-min time lapse was imposed after intake of water or food before CPX. Each participant then underwent symptom-limited maximal CPX and also acted as his own control for each experimental condition. The respiratory gas exchange ratio was significantly smaller in the water condition (0.76 0.06) than in the fasting (0.83 0.01) and jelly (0.83 0.05) conditions at rest, but no other differences in cardiopulmonary responses were evident. These findings suggest that blood distribution to skeletal muscles is prioritized at maximal exercise level even during the digestion and absorption of food. In conclusion, careful consideration should be given to the load on the cardiopulmonary system and quantity and types of fluid or food ingested, when engaging in physical exercise.
OBJECTIVE: To review the strength of research evidence on the effects of exercise and rest breaks on musculoskeletal discomfort during computer tasks and compare the evidence with clinical guidelines. SIGNIFICANCE: The review of research evidence and its comparison with current clinical guidelines provide clinicians with knowledge to make clinically sound decisions in the care and management of individuals with musculoskeletal discomfort during computer tasks. METHODS: Articles from Pubmed, Ovid and references of relevant articles were reviewed for research design and internal validity. Grades of evidence were assigned based on the aggregate strength of articles for each intervention. RESULTS: Fifteen articles (one on exercise, seven on rest breaks, five examining both) met the inclusion criteria. Exercise and rest breaks were each assigned a grade of C. CONCLUSIONS: Evidence supports the use of exercise and rest breaks in reducing musculoskeletal discomfort in computer tasks. The research evidence suggests no additional benefits of exercise over rest breaks alone. Research evidence concurs with the clinical guidelines recommended by OSHA and the Official Disability Guidelines.
When a muscle is used repeatedly for a long time, it often leads to muscular fatigue and muscle soreness. In middle-aged and elderly populations, muscular fatigue and pain during the performance of activities of daily living is a common problem caused by physiological changes in the musculoskeletal system due to the aging process. Microcurrent therapy has been shown to be effective at reducing pain and muscle soreness. For activities such as standing or walking, specially developed shoes (G-man, Busan, South Korea) which are capable of providing microcurrent therapy during the performance of these activities are an advantage as the treatment becomes integrated with the activity being performed. These therapeutic shoes or microcurrent induction shoes could be potentially useful for providing treatment if they were worn during normal activities. The purpose of this study, therefore, was to investigate the effect of these microcurrent induction shoes on pain and muscle fatigue in middle-aged people with plantar fascitis. Subjects were asked to wear their normal shoes and instructed to walk on a treadmill at 2 and 3 km/hr for 10 minutes each. Subjects were then asked to wear the specially designed microcurrent induction shoes for six weeks for at least 4 hours per day during ADL activities such as standing and walking. During the initial evaluation and at the end of the 6 weeks intervention, the electromyographic (EMG) activity of their right tibialis anterior and soleus muscles were recorded, together with their perceived level of foot pain using a Visual Analogue Scale (VAS). The results showed a significant reduction in their VAS scores (p<0.01), and the change in median power frequency of their tibialis anterior EMG recording (p<0.05). In conclusion, this study demonstrated that microcurrent induction shoes were effective in relieving foot pain and muscle fatigue in subjects with plantar fascitis.
The purpose of this study was to compare the accuracy of measurement of lower extremity joint moments calculated using data obtained by a force plate embedded on a stair tread with that using combined data obtained by two force plates under the staircase. We captured ascending and descending movement by a healthy young subject using a three-dimensional motion analysis system. We calculated ankle, knee and hip joint moments using data from the same trial captured by the two measurement methods. No differences were observed in lower extremity joint moments between the two methods. Our theoretical assumptions were confirmed by our results; floor reaction force obtained from the force plates positioned under the stairs was the same as that obtained on the stair tread, and joint moment could be calculated accurately using either measurement method. The use of our simplified experimental setup using force plates positioned under the staircase could facilitate future measurement of floor reaction force and calculation of joint moment during ascending and descending stairs.