Video Analysis Analyzing Tips
|Back to the main Video Analysis Page||When are you analyzing skiers and riders on your computer, keep these tips in mind.|
People universally see the negatives right away when they see themselves on video. Spend at least 1/3, preferably ½ your analysis time focusing on the positives. Using the split screen reference capability makes it much easier to find the positives as well as much easier to believe them.
Develop your skill to separate causes from symptoms. Skidding is a symptom that is usually caused by movements that occur earlier in the turn. Over using rotary or under using edging can be a cause of skidding, but these things can be forced to happen because of stance issues. Use the PSIA visual cues to find both good and bad things!
Split each skier and segment into separate clips. Smaller files are easier to work with and manage.
Use the mouse on the scroll bar to play short sections at various speeds. This is the feature of movement analysis software that helps you train your eyes the best. Start looking for things in still frames. Work your way to seeing things happen at extreme slow motion (i.e. frame by frame). Then use the scroll bar to gradually speed the clip up so that your eyes can see what your looking for at normal speed.
Use reverse image to compare left versus right turns.
Use line drawing tools to check shoulder alignment and hands even and height of the hands.
Use the angle tool to check angulation. Measure from the chin to the middle of the hips to in between the feet. 180 degrees is fully inclinated (i.e. banked). Numbers in the 140s and below are high end skiing. You should not see numbers in the 160s except on very flat terrain and slow speeds. Practice measuring so that you are consistently in within 1 degree measuring the same position. Once you can do this, you can measure progress in achieving better angulation.
Build your own reference library! Measure turn shape by the number of frames between pole touches where the pole is vertical. If you organize your reference library by size of turn shape, then it's easy to find clips that will work well for side by side comparison.
General analysis tips:
Check out Ron LeMaster's movement analysis presentation.
Harald Harb has it own tips for movement analysis.
Divide the turn into 3 phases: initiation, control and completion. In each phase, describe what should happen with edge angles, counter, flexion/extension, angulation, hip movement, pole swing, hand position, shoulder alignment, lateral balance, etc. For inefficient movements, describe what the subject is doing, then show them a reference clip to that shows what you want you want them to do instead. A lot of the symptoms you see in the later phases of a turn MUST happen because of what happened during turn initiation.
Check for equipment issues. A side view can be used to help check fore/aft
balance issues caused by improper forward lean of the boots. Too little forward lean
will cause a skier to bend at the waist too much. Too much forward lean will
cause a skier to drop their hip. How does ramp angle effect this too? If the
boots are undercanted you will see excessive knee angulation and the skis slip.
If they are overcanted, the ski will chatter. Look for poles that are the wrong
length (e.g. check hand height at pole touch).
Check out Snow Performance's visual cues.
Look for psychological signs. Is the subject aggressive or fearful, etc. Look for signs of what tactics are being used.
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