Investigation into the Trampoline Dynamic Characteristics and Analysis of Double Bounce Vibrations

Trampoline Stiffness Estimation by Using Robotic System for Quantitative Evaluation of Jumping Exercises

Trampolines are recognized as a valuable tool in exercise and rehabilitation due to their unique properties like elasticity, rebound force, low-impact exercise, and enhancement of posture, balance, and cardiopulmonary function. To quantitatively assess the effects of trampoline exercises, it is essential to estimate factors such as stiffness, elements influencing jump dynamics, and user safety. Previous studies assessing trampoline characteristics had limitations in performing repetitive experiments at various locations on the trampoline. Therefore, this research introduces a robotic system equipped with foot-shaped jigs to evaluate trampoline stiffness and quantitatively measure exercise effects. This system, through automated, repetitive movements at various locations on the trampoline, accurately measures the elastic coefficient and vertical forces. The robot maneuvers based on the coordinates of the trampoline, as determined by its torque and position sensors. The force sensor measures data related to the force exerted, along with the vertical force data at X, Y, and Z coordinates. The model's accuracy was evaluated using linear regression based on Hooke's Law, with Mean Absolute Error (MAE), Root Mean Square Error (RMSE), and Correlation Coefficient Squared (R-squared) metrics. In the analysis including only the distance between X and the foot-shaped jigs, the average MAE, RMSE, and R-squared values were 17.9702, 21.7226, and 0.9840, respectively. Notably, expanding the model to include distances in X, Y, and between the foot-shaped jigs resulted in a decrease in MAE to 15.7347, RMSE to 18.8226, and an increase in R-squared to 0.9854. The integrated model, including distances in X, Y, and between the foot-shaped jigs, showed improved predictive capability with lower MAE and RMSE and higher R-squared, indicating its effectiveness in more accurately predicting trampoline dynamics, vital in fitness and rehabilitation fields.

SMART System in the Assessment of Exercise Tolerance in Adults

Health-oriented physical activity should meet two key criteria: safety and an optimal level of exercise. The system of monitoring and rationalization of training (SMART) was designed to meet them. SMART integrates a custom-configured inertial measurement unit (IMU) and a sensor with real-time heart rate measurement (HR) using a proprietary computer application. SMART was used to evaluate the safety and exercise load with 115 study participants: 51 women (44.35%) and 64 men (55.65%) aged 19 to 65 years. The exercise test was the 6MWT test. In 35% of the participants, the mean HR exceeded the recognized safe limit of HR 75% max. Ongoing monitoring of HR allows for optimal exercise and its safety. Step count data were collected from the SMART system. The average step length was calculated by dividing the distance by the number of steps. The aim of the present study was to assess the risk of excessive cardiovascular stress during the 6MWT test using the SMART system.

A Public Health Review into Two Decades of Domestic Trampoline Injuries in Children within Queensland, Australia

Trampolining as an activity brings enjoyment and many health benefits, but at the same time it carries an injury risk. Most domestic trampoline users are children who are developing in skill, cognition, risk perception, physical strength and resilience to injury. Several common patterns of child trampoline injuries have been identified and countermeasures outlined in standards have been taken to reduce higher risk injury mechanisms, such as entrapment and falls from the trampoline through design, product and point of sale labelling. In Australia, the first national trampoline standard was published in 2003 which introduced improvements in trampoline design and requirements for labelling and padding. This work investigated the potential impact of these and subsequent changes based on almost two decades of emergency department trampoline injury data collected in Queensland, Australia. These data describe the changing representative proportion and pattern of trampoline injuries in Queensland over time by age, mechanism, gender, severity and nature of injury of injured persons up to the age of 14 years. The interrelationships between different injury characteristics were also analysed to propose the main factors influencing injury occurrence and severity. These findings seem to indicate that safety evolution in the form of enclosure nets, frame impact attenuation and entrapment protection have likely improved domestic trampoline safety. Other factors, such as adult supervision, minimum age and avoidance of multiple users, could further reduce injury but are harder to influence in the domestic setting.