Sarrafzadeh J, Ebrahimi Takamjani A, Khosravi A, Haery F, Seyed Hosseini L,
Volume 64, Issue 12 (6 2006)
Abstract
Background: There is considerable professional debate over which technique is the best for lifting. The aim of this study is to compare three static lifting styles, the stoop, semi-squat and arm lift, using maximum isometric voluntary contraction (MIVC) as one indicator for recommending a lifting style.
Methods: Thirty healthy women (mean age: 22.37 years) participated in this quasi-experimental study. They performed the tests in static postures by standing on the platform of the Lift TrackTM and pulling the dynamometer of the instrument with maximum effort in three lifting styles: the stoop, semi-squat and arm lift. The subjects warmed-up by practicing the lifts first. The mean MIVC from the two other sets of lifts were used for statistical analysis by repeated measurements and SPSS (ver.10) software.
Results: There were significant differences between the MIVC of the three lifting styles in this study. The largest MIVC was for the semi-squat lift and was the least was for the arm lift (p<0.001). The MIVC of the stoop lift was larger than that of the arm lift (p<0.001).
Conclusion: The largest MIVC for the semi-squat lift suggests that this style is useful for lifting objects from the floor. The differences in biomechanical and muscle pattern activity changes could explain these results. It seems that activation of the quadriceps muscles in the semi-squat lift was a main factor for producing more MIVC, so when this style is recommended for lifting, attention to the power of the quadriceps is important.
Mostafa Hosseinabadi, Mojtaba Kamyab, Fatemeh Azadinia, Javad Sarrafzadeh,
Volume 77, Issue 3 (June 2019)
Abstract
Background: The back extensor muscles are the main spinal supportive factors which function establishes spinal stability and erect posture of the spine. Spine deviation from the ideal alignment, like abnormal increase in the forward curvature of the thoracic spine may cause changes in the trunk muscle activity which can lead to a change in the spinal proprioception. It seems that the corrected spinal alignment as a result of an orthotic treatment course facilitates the back muscles activity and improve proprioception. The present study aimed to investigate the changes occurring in thoracic kyphosis, trunk extensor muscle strength and trunk extensor force sense after using the Spinomed orthosis in elderly people with hyperkyphosis.
Methods: Twenty-six elderly people with hyperkyphosis who met the eligibility criteria participated in this preliminary study at School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran, from August to November of 2017. Subjects were randomly allocated to the experimental (wearing the orthosis with maintaining the daily physical activities) and control (maintaining daily physical activities) groups. Degree of kyphosis, absolute error of force sense and trunk extensor muscle strength were measured in all participants before and after intervention for 9 weeks.
Results: Thirteen elderly people with 63.85±4.63 years old in the experimental group and thirteen elderly people with 66.92±3.25 years old were participated in data analysis. The results showed significant reduction in degree of kyphosis (P<0.001) and absolute error of force sense (P=0.001), and improvement of trunk extensor muscle strength (P=0.021) in the experimental group. Independent t-test results showed a significant difference between experimental and control groups with better outcomes in terms of posture correction (P<0.001) strength (P=0.002) and force sense (P=0.035) in the orthosis group.
Conclusion: Using Spinomed orthosis for 2 months (2 hours per day) appears to have some benefit in terms of back extensor muscle strength and muscle force control. Also, Spinomed orthosis can be prescribed to improve spinal posture.
