Locomotion
Goals:
- Maintain or achieve a certain velocity (usually a forward velocity)
- Cover a certain distance, be the fastest, and decrease injury
- Do all of this efficiently
- stride rate x stride length = velocity
Biomechanical Factors (example with speed skating)
Stride length
-will be determined by strength, joint angles, motor patterns, etc.
o impulse momentum theorem: force x time = change in momentum. The momentum is proportional to velocity
Biomechanical factors of the push phase of stride
· leg length and range of motion
· angle of the skate- need the optimal angle, not straight and not perpendicular
· the speed before the push phase starts (from the previous glide)
· body position- too low will cause fatigue, balance problems, and too much vertical movement. But, too high will cause more drag and air friction
Biomechanical factors of the glide phase of stride
· aerodynamics- faster moving objects, larger surface areas, and lighter objects will be most effected
· drag force- so starting glide speed doesn’t deteriorate as much you need…
o correct body position by decreasing your frontal area (less surface area)
o small coefficient of drag (less air friction)- impacted by clothing, equipment, and body position
· starting speed of the glide (from the previous push phase)- you want to maintain as much speed as possible so you don’t have to work to gain it all back
Stride rate
the goal is to minimize turnover and transition between phases
· can start push phase earlier (but not too early, want to maximize glide)
· don’t push too wide or wait until you start slowing down in the glide to start the push
· can push for a shorter time and smaller range of motion (find your optimal range for efficiency)
· increase power output- same ROM and distance, but doing so faster
Critical Features to look for when observing locomotion: (example with speed skating)
For speed-
· range of motion
· angle of the skate
· quickness of the push
· timing of the push
· body position
· equipment
For efficiency/injury reduction-
· joint alignment: most power movement should occur in the sagittal plane. Minimize frontal and transverse plane movements.
Observation Plan
· Watch the frontal and sagittal plane
· Start at the feet and work our way up the kinetic chain
· Listen to foot strike for control
· Can control the environment with the treadmill (running), but not sprinting
Attached below is an observation checklist to guide your observations of locomotion. This is an example for running, just print it out and take it with you to observe a runner!
Stride length
- Leg length (will increase displacement)
- Range of motion
- Force you push off with for displacement
-will be determined by strength, joint angles, motor patterns, etc.
- Related theorems for generating velocity:
o impulse momentum theorem: force x time = change in momentum. The momentum is proportional to velocity
Biomechanical factors of the push phase of stride
· leg length and range of motion
· angle of the skate- need the optimal angle, not straight and not perpendicular
· the speed before the push phase starts (from the previous glide)
· body position- too low will cause fatigue, balance problems, and too much vertical movement. But, too high will cause more drag and air friction
Biomechanical factors of the glide phase of stride
· aerodynamics- faster moving objects, larger surface areas, and lighter objects will be most effected
· drag force- so starting glide speed doesn’t deteriorate as much you need…
o correct body position by decreasing your frontal area (less surface area)
o small coefficient of drag (less air friction)- impacted by clothing, equipment, and body position
· starting speed of the glide (from the previous push phase)- you want to maintain as much speed as possible so you don’t have to work to gain it all back
Stride rate
the goal is to minimize turnover and transition between phases
· can start push phase earlier (but not too early, want to maximize glide)
· don’t push too wide or wait until you start slowing down in the glide to start the push
· can push for a shorter time and smaller range of motion (find your optimal range for efficiency)
· increase power output- same ROM and distance, but doing so faster
Critical Features to look for when observing locomotion: (example with speed skating)
For speed-
· range of motion
· angle of the skate
· quickness of the push
· timing of the push
· body position
· equipment
For efficiency/injury reduction-
· joint alignment: most power movement should occur in the sagittal plane. Minimize frontal and transverse plane movements.
Observation Plan
· Watch the frontal and sagittal plane
· Start at the feet and work our way up the kinetic chain
· Listen to foot strike for control
· Can control the environment with the treadmill (running), but not sprinting
Attached below is an observation checklist to guide your observations of locomotion. This is an example for running, just print it out and take it with you to observe a runner!
Locomotion Observation Checklist | |
File Size: | 13 kb |
File Type: | docx |
Evaluation Plan
· Confirm “live” observations using video
· Find out if they have any problems/ injuries that could be related to their form
· Figure out if you want to change it. Is it really necessary for their skill?
· Are issues anatomical or muscular?