Measuring running speed

Measuring running Speed

One of the current physiology lab work look into predicting performance by measuring max velocity over 50m and Sub max effort on the treadmill

To measure the maximum velocity of an individual, it was proposed on the paper to use timing gate as a valid measure. As we have only 5 pairs of timing gates available, they will be placed 5m apart after 25m (according to research, max speed of most individual is achieved around 37m ).

One of my lab mate, Lap Yin feels that a more accurate yet feasible method of achieving the maximum velocity is using video analysis by Silicon Coach. The procedure is as follows:

1. Set up the camera with a vision of 20m (25m to 45m of the 50m run).

2. A person carrying a metre ruler will stand in between the 20m vision to allow for later calibration.

3. Capture the subjects' 50m trials

4. Playback the trials and analysis the data on Silicon coach 

5. Using the metre ruler, the captured video will be calibrated. Next, we will predetermined a point(heel of his foot strike) on the subject's body which we will used consistently to mark out the displacement he has covered. Silicon Coach will automatically generate the distance covered and the speed he achieved within that dermarcated distance.

AAR(After action review)

1. Area of improvement

 - Better camera can be used to obtain better video quality so ambiguity due to blurred distorted pixel can be further rule out. 

 - 2 or more synchronised cameras can be used in tandem so we can cover a wider area so we can probably analysis the entire running sequence.

-  Use a more prominent marker that can be viewed from far and attached it to a body part (i.e greater trochanter) which has lesser variable movement during running.

Lap Yin and I feel that it is a more reliable measure of maximum velocity as compared to the 5 pairs of timing gates available. However, it is not known if it is a valid measure. Any comments?

Brief introduction of Timing gate

Timing gates are very valuable tools for the exercise physiologist for timing measurement during fitness testing. Timing gates are most widely used for sprint testing, though many systems can be used for other applications such as vertical jump and reaction time.

Uses

There are several types of timing gates made specifically to measure running speed in fitness testing. Compared to the alternative of using a stopwatch, the timing gate provides an accurate and reliable measure of speed.

Using infra-red signal and detectors, the gates record when the beam is broken. Using different configurations, the gates should be able to be used for single sprint, repeat sprints, running back and forth through same gate, and multiple people sprinting in different lanes. Some systems may also come with a timing switch mat to use for vertical jump testing.

Adapted from http://www.topendsports.com/testing/timing-gates.htm

Treadmill vs Outdoor running

Kineseology (study of the movement of the body) point of view

There is a measurable difference in the muscles being trained on a treadmill than the ones that make you . The major difference tends to be in the calves, which propel the body forward at the end of the stride. The quads push the body forward to some extent, but the majority of the motion comes from lower down. The hamstrings pull the lower leg into a recovery position so that the hip flexors can move the whole assembly back to the starting position. On a treadmill, the brain quickly realizes that the firing of the calves isn't moving the body forward in relation to the rest of the room and that lessing of the energy used won't cause any dimunition of speed. Since the body gradually finds the most efficient way to accomplish any physical task, it slowly shuts down the calves until they're only working at about 35% of what they would outdoors. For people that feel that they work harder on treadmills, it's probably either mental or they have a different gait.

Other possible Explanations

Physically, there may be some slight differences between how your body expends energy running on a track versus a treadmill.

• The treadmill belt offers some help by pulling your feet back underneath your body, so you are potentially exerting less energy to move your feet and legs than if you were not on a treadmill.
• When you run indoors on a treadmill, you do not have to overcome wind resistance. The lack of wind means you'll spend less energy running four miles on a treadmill than you will running four miles outdoors. However, it may depend on how fast you are running. For the average person, running 5 - 9 miles per hour (mph) will result in little difference. Some studies say outdoor running expends up to 5 percent more calories; if you run faster than 9 mph, running outdoors could utilize up to 10 percent more calories because you are working harder against wind resistance. Other studies say there's no difference. One study demonstrated the way to balance energy use between indoor and outdoor running is to set the treadmill at an incline (or grade) of 1 percent.
• Running indoors maintains or offers stable elements. Runners not only avoid wind, but also other potential natural elements, such as cold air, rain, or sand (if you run on a beach), which demand extra energy.
• Running on a treadmill versus pavement (the composition of the track surface you run on is unclear) provides a softer surface, making it a little easier for your joints. People with knee pain or soreness might opt for a treadmill versus the road outside for this reason.

adapted from http://www.goaskalice.columbia.edu/3049.html