I’ve been getting a ton of questions about running data ever since Apple announced that they would be adding running dynamics to the Apple Watch, so I wanted to share some content about one of the metrics they are using. First, I want to say that I am thrilled to see Apple add data to their running programs. Hopefully, this will help show people there is a lot more to running than lacing up your shoes and heading out the door. Having a company as large as Apple focus on the finer parts of running may help runners understand there is a lot of skill and science involved. So, the metric I want to talk about this month is "vertical oscillation". (I think google search for this term went up 1000% after the announcement!) As for all of these metrics, the term itself is pretty easy to understand…knowing what to do about it is the important part. Vertical oscillation is defined as the amount of upward/downward motion a runner goes through while running. It is calculated by taking the difference of the maximum height (typically achieved when both legs are off the ground in the flight phase) and the minimum height (typically achieved around mid-stance when the runner has 1 foot on the ground).
The reason this number is important is that we want to maximize the distance we cover with each stride while maintaining good form. One way we do that is by maximizing the forward motion while in flight during running. If vertical oscillation is too high, you spend less time moving forward and more time moving up/down while in the air. If vertical oscillation is too low, flight time is reduced, and you increase your time on the ground. So you are probably asking yourself: what is too high and what is too low? The answer: there are some ranges we commonly see but it does depend on height and running form. Typically, a range of 6-9 cm is within a desired range. The nice thing about this number is that it has been around and fairly easy to measure for quite some time. I published a paper in 2016 showing how a wearable device measured up well compared to a 3D motion analysis system. Even better, this metric is something that you can modify and can use to measure improvements in running form. In our Certified Running Gait Analyst course, we call someone with excessive vertical oscillation a “Bouncer”. There are lots of different cues running specialists can give to help runners reduce bouncing. One of my favorite cues for people with long hair is to have them focus on not letting their pony tail bounce up and down too much! We also see that vertical oscillation can relate to other common running data metrics. In 2018, I published a study that showed increasing running cadence can reduce vertical oscillation. Most often, runners will want to lower vertical oscillation. If your cadence (step rate) is lower than 168, that may be an effective strategy you can track with wearable tech. We also don’t want vertical oscillation to be too low, and I had a good example of that this week. Check out the video below to see how we taught one runner who had a shuffling pattern to drive their knees (and what a big difference this made in their form).
Hopefully this gives you some background on what vertical oscillation is, and how it can help your form. If you are looking for more information about this or other running metrics, please sign up for our free upcoming webinar, where we will talk about all sorts of running data - the good the bad, and the ugly!