Biomechanics

Biomechanical Principles Buoyancy Force Friction Torque Drag

Buoyancy Definition an upward force exerted by a fluid that opposes the weight of an immersed object Example Freestyle Swimmer staying somewhat on top of water because he/she is neutrally buoyancy. Floating in Water

Force Definition An influence that tends to change the motion of an object Example Push or Pull of the arm during the freestyle swim. Kicking from Hip Hands make “cup” to move water so swimmer can advance.

Torque Definition The moment of a force or a system of forces tending to cause rotation. Example Twisting, turning, or rotating force. 1. In freestyle your core should turn side to side which each arm stroke. This is Torque. 2. Rotational Force (Torque) are dependent on the length of the lever (arms and legs) and the strength of the individual. 3. Flexibility also plays an important role in generating torque. 4. Increase the extension of the arms. 5. Kick from the Hips.

Friction Definition Surface resistance to relative motion Example Water is constantly flowing over the body while in motion. This causes a slight resistance. This Causes friction. Friction relatively stays the same at different velocities in the water. Suit Skin Hair Decrease Friction by: wearing swim caps, wear tight fitting suits, shave.

Drag Definition A force that acts to slow down the motion of a body moving through fluid. Example Body moving through water causes drag Faster the swimmer goes, the more drag that is produced. Body position in the water affects drag. A more torpedo like body will produce less drag than a box like body. Decrease Drag by: keep body streamline position, keep head in line with trunk, hand entry and recovery should enter and recover in and out of the water as smooth as possible. Do not kick any higher, deeper, or wider than necessary.