Buoyant (leg-sinking) torque in able-bodied swimmers and swimmers with impaired leg function

Biography

Dr Carl Payton is a Senior Enterprise Fellow in Biomechanics at Manchester Metropolitan University in the UK. His current research interests are in the biomechanics of elite swimmers with a disability. Carl has led the delivery of biomechanics support services to the Great Britain Para-swimming team since 2000 and he is also a member of the IPC Swimming research group who are focusing on the Para-swimming functional classification system.

Synopsis 

A swimmer’s ability to float statically in a horizontal position is determined largely by the turning effect of their body weight and buoyancy forces. This is termed the buoyant torque. Due to sex differences in body mass distribution, males generally experience a greater buoyant torque than females, resulting in a greater tendency for their legs to sink (e.g. McLean and Hinrichs, 1998). Para-swimmers who are unable to kick, due to impaired leg function, may be disadvantaged over those competitors who can kick. Not only are they unable to use a leg-kick to help maintain horizontal alignment, but their body mass distribution, due to atrophied lower extremities, may differ from that of non-impaired swimmers and so, consequently, may the buoyant (leg-sinking) torque they experience. This study’s aim was to establish whether the buoyant torque differs between swimmers with impaired leg function (ILF) and able bodied (AB) swimmers.