The ability to coordinate different body parts under different constraints that are imposed by organism, environment, and tasks during motor development might be different in children. The aim of this study was to examine whether children with different motor development levels are different with regard to multijoint coordination during two-hand catching. Eighty-four children (age: 6.05 ±0.67 years) who were assessed on object control skills were recruited voluntarily. The biomechanical model was defined from 20 movements of seven segments (shoulders, elbows, wrists, and torso), and the principal component analysis was used to quantify the multijoint coordination and kinematic synergies during catching. The results showed that the redundancy of joints in two-hand catching is controlled by three kinematic synergies that defined the majority of the variance. The participants who were grouped based on their development levels did not show differences in the number and strength of synergies; however, they were different in the utilization of the kinematic synergies for successful catching. In conclusion, the number and the strength of the kinematic synergies during two-hand catching are not affected by the developmental levels and are related to the nature of the task.
Marzie Balali, Shahab Parvinpour, and Mohsen Shafizadeh
Mohsen Shafizadeh, Nicola Theis, and Keith Davids
The aim of this study was to examine strategies to absorb impact shock during RaceRunning in participants with neurological motor disorders. For this purpose, 8 RaceRunning athletes (4 male and 4 female) voluntarily took part in the study. Each participant performed a series of 100-m sprints with a RaceRunning bike. Acceleration of the tibia and head was measured with 2 inertial measurement units and used to calculate foot-impact shock measures. Results showed that RaceRunning pattern was characterized by a lack of impact peak in foot–ground contact time and the existence of an active peak after foot contact. Due to the ergonomic properties of the RaceRunning bike, shock is attenuated throughout the stance phase. In conclusion, the results revealed that RaceRunning athletes with neurological motor disorders are capable of absorbing impact shock during assisted RaceRunning using a strategy that mimics runners without disabilities.
Mohsen Shafizadeh, Jane Manson, Sally Fowler-Davis, Khalid Ali, Anna C. Lowe, Judy Stevenson, Shahab Parvinpour, and Keith Davids
The incidence of falling, due to aging, is related to both personal and environmental factors. There is a clear need to understand the nature of the major risk factors and design features of a safe and navigable living environment for potential fallers. The aim of this scoping review was to identify studies that have examined the effectiveness of environments, which promote physical activity and have an impact on falls prevention. Selected studies were identified and categorized into four main topics: built environment, environment modifications, enriched environments, and task constraints. The results of this analysis showed that there are a limited number of studies aiming to enhance dynamic postural stability and fall prevention through designing more functional environments. This scoping review study suggests that the design of interventions and the evaluation of an environment to support fall prevention are topics for future research.