Sedentary lifestyle of university students is detrimental to the thoracic spine in men and to the lumbar spine in women.

BACKGROUND: Sitting for long periods of time and lack of physical activity in young adults can cause postural deterioration leading to rapid onset of fatigue and increase the risk of back pain. We were interested in whether there are gender differences in spinal curvature among university students with a predominantly sedentary lifestyle. METHODS: 20 sedentary female (age 20 ± 0.73 years) and 39 sedentary male university students (age 20 ± 1.08 years) participated in this study. Their thoracic and lumbar curvatures were assessed while standing and sitting using a Spinal Mouse. RESULTS: In standing, 80.0% of the females and 69.2% of the males had a neutral position of the thoracic spine (33.25° and 35.33°, respectively). However, more males, 30.8%, than females, 10.0%, had hyperkyphosis (54.27° and 47.0°, respectively). Hypokyphosis was found in 10.0% of the females (18.50°) and none in the males. Similarly, 90.0% of the females and 97.4% of the males had neutral position of the lumbar spine (-33.11° and -29.76°, respectively). Increased hyperlordosis was found in 10.0% of the females and 2.6% of the males (-41.0° and -50.0°, respectively). Hypolordosis was not detected in either females or males. In sitting, on the other hand, 70.0% of the females and only 33.3% of the males had a neutral position of the thoracic spine (30.20° and 30.62°, respectively). Increased hyperkyphosis was found in 46.2% of the males (59.76°) and none of the females. 30.0% of the females and 23.1% of the males had light hypokyphosis (47.50° and 46.67°, respectively). Similarly, 70.0% of the females and only 38.5% of the males had a neutral position of the lumbar spine (7.0° and 6.6°, respectively). 35.9% of the males and only 5.0% of the females had a light hypokyphosis (16.14° and 16.0°, respectively). Slightly increased hyperkyphosis was identified in 25.6% of the males and 25.0% of the females (23.9° and 22.5°, respectively). CONCLUSION: There are significant gender differences in spinal curvature. While in the thoracic spine it was to the detriment of the males when both standing and sitting, in the lumbar spine it is related to the females only when standing. It is therefore necessary to eliminate these spinal deviations in young adults induced by prolonged sitting during university courses by appropriate recovery modalities.

Resistance and Strength of Conductive PLA Processed by FDM Additive Manufacturing.

There is a large number of materials that can be used for FDM additive manufacturing technology. These materials have different strength properties, they are designed for different purposes. They can be highly strong or flexible, abrasion-resistant, or designed for example for environments with higher thermal loads. However recently new innovative and progressive materials have come to the practice, which include nano-composite particles, bringing new added value. One such material is the Conductive PLA material, which is capable of conducting electric current. The aim of this article is to present the material properties of this material. The article describes the design of the experiment, the process of measuring the resistance of samples printed by FDM device, measuring the maximum tensile strength of samples. The article includes a statistical evaluation of the measured data, with the determination of the significance of individual factors of the experiment as well as the evaluation of the overall result of the experiments.