Hello this is Fukuma from LEOMO. I would like to pick up from where left off in Part 1 “What is LAR/FAR”? In this article I would like to discuss some of practical applications for those two MPIs.
Let us first discuss the value size, ranges, and correlations between LAR and FAR. Generally speaking, LAR is between 45 and 60 degrees while the FAR is between 40 and 50 degrees. Any value that falls outside of this range might be caused by atypical movement.
For example, if the FAR exceeds 70 degrees we could infer that as the athlete comes over the top of the pedal stroke (12 o’clock) his toes are pointed down and the heel is angled upwards. Likewise, when a cyclist LAR exceeds 75 degrees we might conclude that their crank might be too long, their saddle too far forward, and/or they are sitting on the front edge of their saddle. When the LAR exceeds 75 degrees, the cyclist’s position might be shifted forward too much or the crank may be too long- although that also means that the cyclist has the flexibility to compensate for this. It is important to note that the values that we suggest are guidelines. LAR in itself can give great insight, but to make concrete performance and fit changes one should also look at the entire kinetic chain.
LAR and FAR are often correlated. Performing a heel-up position at the top of the pedal stroke (12 o’clock) will increase FAR while simultaneously increasing LAR because the top of the thigh travels further up. LAR and FAR signify the range, and the way the different body parts interact with each other. These ranges will give the athlete more insight about their movement and allow them to draw deeper conclusions from the measured values.
Another easy to understand application is to compare the left/right differences in LAR and FAR.
Since the LAR and FAR signify angular ranges, one could see a difference in motion between the left and the right thigh and between the left and right foot. Similar to how people have a dominant hand, they can also have a dominant leg. Some athletes can feel a difference between right and left that isn’t related to muscle mass or flexibility (there are very few people who can throw a ball with their non-dominant hand as well as they can with their dominant hand). As a result, we can say that a difference of one or two degrees is negligible. Depending on the athlete, a difference of five or ten degrees is also possible, and in those cases, we can say that there is room for improvement.
Another potential cause for a drastic difference in left/right LAR and FAR is a difference in leg length or flexibility resulting from a past injury or accident. In these cases, it is better to change the length of the crank or the lateral position of the cleat rather than aim to improve performance through effort.
Why is Angular Range important?
With the TYPE-R IMU based technology we are able to calculate range of motion based off of minimum and maximum angles. Cycling is a repetitive, constant movement with no particular instant when action stops. With this in mind, it is important to measure the range on movement.