ABSTRACT
Objective To evaluate the effectiveness and safety of isometric neck strength training for the treatment of neck-type cervical syndrome.Methods The qualified patients with neck-type cervical syndrome were divided into two groups by stratified randomization: the treatment group(N=55)received isometric neck strength training,and the control group(N=40) received manipulation treatment.Two weeks constituted one treatmeat course.Visual Analog Scale(VAS) and Vernon Cervical Disability Index(VCDI) were used to evaluate the efficacy,and the safety was also monitored.Results All of the 95 enrolled patients were followed up for 3~11.4 months.No aggravation was found in the treatment group,but in the control group one patient developed into cervical spondylotic radiculopathy and one patient developed into sympathetic cervical spondylosis.The frequency of serious neck pain attack within 3 months was 6.65?2.62 times in the control group and 2.27?1.50 times in the treatment group,the difference being significant(P0.05);the result of follow-up on the 3rd month after treatment showed that the difference of VCDI score was significant between the two groups(P
ABSTRACT
The present studies were performed to investigate changes of reaction time and increase of muscle strength by isometric training of biceps brachii muscle. The intensity of its training was the three types of maximal voluntary contraction (MVC), 70%MVC and 50%MVC. EMG reaction time (EMG-RT) as a function of motor control in center nervous system was measured by isometric contraction on fixed elbow.<BR>After training for 8 weeks period, integrated EMG (IEMG) and power spectorum (mean power frequency, MPF) were increased as a component of muscle strength. IEMG and MPF were increased 83.6% and 16.6% in MVC training group, and were increased 86.2% and 20.8% in 70%MVC training group, and were increased 69.2% and 13.2% in 50%MVC training group. Increase of muscle strength in MVC, 70%MVC and 50%MVC training group increased 36.8%, 42, 3% and 30.6%, respectively. Consequently, decrease of EMG-RT was markdly associated with increase of muscle strength. The heavy intensity of isometric training, MVC and 70%MVC groups, decreased the EMG-RT greater than 50%MVC training group. Therefore, the decrease of training-induced EMG-RT correlated to development of muscle strength due to stimulation by training intensity. These results suggest that the decreased EMG-RT might be due to stimulation on motor central system by muscle training of heavy intensity.
ABSTRACT
The present studies were performed to investigate changes of reaction time and increase of muscle strength by isometric training of biceps brachii muscle. The intensity of its training was the three types of maximal voluntary contraction (MVC), 70%MVC and 50%MVC. EMG reaction time (EMG-RT) as a function of motor control in center nervous system was measured by isometric contraction on fixed elbow.<BR>After training for 8 weeks period, integrated EMG (IEMG) and power spectorum (mean power frequency, MPF) were increased as a component of muscle strength. IEMG and MPF were increased 83.6% and 16.6% in MVC training group, and were increased 86.2% and 20.8% in 70%MVC training group, and were increased 69.2% and 13.2% in 50%MVC training group. Increase of muscle strength in MVC, 70%MVC and 50%MVC training group increased 36.8%, 42, 3% and 30.6%, respectively. Consequently, decrease of EMG-RT was markdly associated with increase of muscle strength. The heavy intensity of isometric training, MVC and 70%MVC groups, decreased the EMG-RT greater than 50%MVC training group. Therefore, the decrease of training-induced EMG-RT correlated to development of muscle strength due to stimulation by training intensity. These results suggest that the decreased EMG-RT might be due to stimulation on motor central system by muscle training of heavy intensity.
ABSTRACT
The purpose of the present study was to determine the effect of isometric strength training in prepubescent boys and girls on muscle strength and cross-sectional area of upper arm muscle. Subjects were ninety-nine healthy elementary school children from the 1 st, 3 rd and 5th grades and who were assigned to either training (TG, n=52) or control (CG, n=47) groups. The TG participated in a strength training program for 12 weeks which consisted of three maximaly sustained isometric contractions of elbow flexion for ten sec, twice a day, three days per week, whereas the CG did not participate in a special training program during this period. The cross-sectional areas of whole tissue, muscle, fat, and bone of the upper arm were measured by ultrasonic methods. Maximum isometric and isokinetic muscle strength of elbow flexion and extension were measured by means of a Cybex II. The hand-wrist X-ray photograph was used to estimate the skeletal age (TW 2 method) . Means (SDs) of skeletal age (yrs) were 6.27 (0.98), 8.48 (0.89), and 10.77 (1.22) for 1 st, 3 rd, and 5 th graders, respectively. After the 12-week training period, the cross-sectional area of the whole tissue increased significantly in both TG (8.9%, 2.52 cm<SUP>2</SUP>) and CG (7.3%, 2.11 cm<SUP>2</SUP>) . This interment in the TG was due to the significant increases in both muscle and bone areas, while that in CG was due to the significant increase only in fat area. Mean increase in muscle area in the TG was 10.3% (1.29 cm<SUP>2</SUP>) with this increase notable in 5th graders (12.5% for males and 12.7% for females) . The increment in cross-sectional area of muscle with training significantly correlated with the skeletal age (r=0.36, p<0.01) . Maximum isometric strength in the TG increased by 5.7% (0.3kg) in flexion and 17.5% (1.2 kg) in extension and in the CG, -0.3 kg (-1.0%) in flexion and 5.7% (0.3 kg) in extension. The increases in the strength of elbow extension were statistically significant in 1st (p<0.01), 3rd (p<0.05), and 5th (p<0.05) grade males. On the other hand, maximum isokinetic strength did not change with training. Muscle strength per cross-sectional area did not show a significant increase except in the training group of 5th grade boys. It was suggested that the effects of strength training on muscle area and strength for prepubescents were similar in its direction to but different in its magnitude from those found in adults.