ABSTRACT
Objective:To analyze the activation characteristics of trapezius muscle in normal people, and explore whether different interventions could restore the activation pattern of people with abnormal trapezius muscles to normal during subsequent exercises. Methods:From September to October, 2017, 20 persons with normal shoulder joints (control group) and 20 persons with mild discomfort in shoulder joints (observation group) participated in the study. All of them were treated randomly with four steps, including no intervention, static traction of upper trapezius muscle (UT), isometric contraction of lower trapezius muscle (LT) and combined intervention. Then, they were asked to complete three actions, including straight arm side lifting, sitting in rowing and flying birds. Myoelectric signal was recorded before and after test. Results:Compared with the control group, the UT activation degree increased (P < 0.05), and the activation time shortened (P < 0.05); the activation degrees of middle trapezius muscle (MT) and LT decreased (P < 0.05), and the activation time delayed (P < 0.05); the ratios of UT/LT and UT/MT increased (P < 0.05) in the observation group with no intervention. After static traction of UT, isometric contraction of LT, and both interventions, the MVE%, activation time and the ratios of activation varied in different muscles under different actions in both groups (P < 0.05). Conclusion:In different actions, the activation degree and activation time of three trapezius muscles are different. Static traction of UT and isometric contraction of LT before exercise could improve the activation pattern of trapezius muscles of people with shoulder joint discomfort during exercise, which is conducive to the normal function of the shoulder joint.
ABSTRACT
Objective To compare the differences in gait characteristics and stability of women walking with or without sports bra. Methods Twelve women with C cup breast were required to walk on the treadmill (at the speed of 6 km/h) with and without sports bras, respectively. Their gait parameters were collected by using Qualisys Track Manager high-speed infrared motion capture system. Results Compared with the bare-breasted condition, the maximum and minimum angles of the upper trunk were significantly smaller when subjects wearing the sports bra, the range of trunk flexion angles and trunk torsion angles were also relatively smaller, and the standard deviation of hip flexion angles during 10 gait cycles was obviously smaller. However, no differences were found in stride frequency between two breast support conditions. Conclusions Different breast support conditions have a significant influence on the upper trunk angle, trunk flexion angle and trunk torsion angle. Walking without bra will increase the range of trunk angle and deteriorate the walking stability. The stride frequencies under different breast support conditions have individual differences.
ABSTRACT
Objective To compare the differences in gait characteristics and stability of women walking with or without sports bra.Methods Twelve women with C cup breast were required to walk on the treadmill (at the speed of 6 krn/h) with and without sports bras,respectively.Their gait parameters were collected by using Qualisys Track Manager high-speed infrared motion capture system.Results Compared with the bare-breasted condition,the maximum and minimum angles of the upper trunk were significantly smaller when subjects wearing the sports bra,the range of trunk flexion angles and trunk torsion angles were also relatively smaller,and the standard deviation of hip flexion angles during 10 gait cycles was obviously smaller.However,no differences were found in stride frequency between two breast support conditions.Conclusions Different breast support conditions have a significant influence on the upper trunk angle,trunk flexion angle and trunk torsion angle.Walking without bra will increase the range of trunk angle and deteriorate the walking stability.The stride frequencies under different breast support conditions have individual differences.
ABSTRACT
Objective To investigate the effects of overweight and obesity on the gait of primary school children by comparing the kinematic parameters between overweight/obese children and normal weight children during level walking. Methods Forty overweight/obese children (age: (9.6±1.72) year; height: (142.16±12.19) cm; BMI: (24.32±2.96) kg/m2) and 50 normal weight healthy children (age: (10.26±0.72) year; height: (139.0±7.50) cm; BMI: (17.08±1.25) kg/m2) were recruited as the subjects. All of the subjects completed 3 walking trials at preferred speed along a 10 m walkway with barefoot. A digital video camera was used to record these subjects’ level walking images, and their gait parameters, such as step length, stride length and joint angle of the lower extremity, were obtained through Shixun motion analysis system. SPSS 16.0 was used for data analysis. A paired t-test was used to assess differences of all the variables between lefe side and right side for the subjects. An independent t-test was used to assess differences of all the variables between the overweight/obese and normal weight children. Statistical significance was defined as P<0.05. Results (1) There were significant differences between overweight/obese children ((0.44±0.001)) and normal weight children ((0.45±0.001)) for relative step length (P<0.05). (2) There were significant differences in left hip and knee joint angle in the frontal plane between overweight/obese children (left hip angle: (165.36±5.29)°, left knee angle: (178.82±5.51)°, right knee angle: (177.84±5.25)°) and normal weight children (left hip angle: (161.99±4.28)°, left knee angle: (174.67±4.91)°, right knee angle: (174.67±4.91)°) during heel strike phase (P<0.05). Significant differences were found in the left ankle joint angle of the frontal plane during toe off phase between overweight/obese children((121.73±8.03)°) and normal weight children((118.44±6.70)°)(P<0.05). Conclusions Relative step length of overweight/obese children was significantly smaller than that of normal weight children during level walking. The left hip and knee joint angle in the frontal plane of overweight/obese children during heel strike phase were significantly larger than those of normal weight children. The left ankle joint angle in the frontal plane of overweight/obese children during toe off phase was significantly larger than that of normal weight children. These differences may affect the function of the lower extremity in overweight/obese children.