Unsmooth Pedaling Caused by Left-Right Imbalance

Hi, I’m Naoto from the R&D department at LEOMO. Today I’m going to share how the TYPE-R helped me find the 1) imbalance between my left and right pedaling motions, 2) why that imbalance was occurring, and 3) make changes to my training program.

Here’s a long distance ride to show how I found the cause of my imbalanced pedaling. This is a good ride to analyze motion since it includes various types of pedaling: long stretches of flat surfaces, climbs, and downhill sections.

LEOMO TYPE-R Data

It’s easy to do a highly contextual analysis of your power and cadence data using the PSI (Pedal Stroke Intelligence) chart on the LEOMO Web App. The PSI chart combines power, cadence, and motion data in a visually intelligent way (with filtering) that gives insight into your pedaling stroke.

Unsmooth Pedaling LEOMO TYPE-R 2

Observation

I filtered the data to only include the cadences I use (76–100 rpm) when racing. As you can see, there’s a big difference between the “shape” of my left and right PSI charts above.

  • Left leg: DSS concentrated between 11–1 o’clock, with a little around the 6 o’clock position.
  • Right leg: DSS concentrated between 4–6 o’clock, with a little between the 10–11 o’clock position.

Analysis

My left Leg Angular Range is smaller than my right Leg Angular Range. My hypothesis is that the left side’s (1) core muscles are weak and (2) flexibility of the hamstrings are low, so it’s difficult for the left thigh to carry the leg up through the 12 o’clock position. The right leg steps down hard around the 4–6 o’clock position to assist the left leg to carry over the 12 o’clock position, causing simultaneous occurrences of un-smoothness (Dead Spots) on both the left and right legs, and on opposite sides of the pedaling stroke.

Summary

By observing the PSI chart along with other MPIs (this time Leg Angular Range), I was able to discover that I had an unbalanced left/right pedal stroke, with the data suggesting that I had a less dynamic left side, most likely from an inflexible left hamstring. As a result, I added two different routines to my training:

  1. Jack-knife stretches to stretch my left leg’s hamstrings.
  2. Push-ups to increase the strength around my shoulder area. This is to hold my upper body up longer and with a higher arc to allow more room for my thighs to move up and down. Later analysis of my training and race photos showed an ancillary form break hinted at by changes in my Leg Angular Range values: my upper body, starting from the scapula, caved in during race scenarios.

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