Are There Any Benefits In Running With Zero Drop Shoes?

My wife's zero drop running shoes

Although you don't see it as much now, the minimalist type running shoes were the rage all few seasons ago. These minimalist type (and not the barefoot type) usually have a relatively low heel to toe drop. Meaning the height in the midsole and the outsole at the back of the shoe is almost level and/or no difference in height.

One proposed benefit of zero drop running shoes is that it may reduce injury. Shoes with a large drop encourage severe heel striking which can contribute to knee injuries. With zero drop shoes, it may also allow your feet to land as if you were not wearing shoes which helps to distribute impact forces.

Shoes with a high drop may also tilt you forward too much and contribute to alignment and compensatory discrepancies.

If you visit the running section of most running stores now, most midsoles of current running shoes are almost back to before when they were much thicker. But many manufacturers have retained the zero drop while offering plenty of cushioning like the Hokas and Altras.

A recent study however found that a shoe's heel to toe drop may not have have anything to do with running injuries.

The researchers studied 533 non elite runners wearing running shoes with 0, 6 or 10 millimetres (mm) drop for six months. The running shoes were 2l mm in the heel and forefoot, 21 mm in heel and 15 mm in forefoot and 24 mm in heel and 14 mm in forefoot respectively. The shoes were otherwise similar.

25 percent of the runners reported being injured during the six month study period. An injury was defined as leg or lower back pain that resulted from running and prevented planned running for at least one day.

The main finding of the study was that injury rates among the three groups were similar, regardless whether their shoes had a heel to toe drop of 0, 6 or 10 mm.

However, among the runners who ran more frequently, those in the 0 or 6 mm drop shoes had a higher injury rate than the frequent runners with a 10 mm drop.

The researchers suggested that that this may be due to the runners transitioning to fast from their regular running shoes to zero drop shoes leading to increased injury rates as 78 percent of the runners recruited in the study hadn't run in zero drop shoes before.

I remember when I was racing cross country races as a kid we used to train in heavier cushioning shoes and then switched to racing flats for the race. It was very common to have sore calves after the first few races of the season as I've not done enough running in the racing shoes (which had lower drop than the training shoes). Yes, racing flats back then were very similar to the zero drop shoes now.

It was more apparent (sore calves) switching to racing spikes for the track training and track meets when cross country season ended and I raced in track events.

As I always tell my patients, their running technique is much more important than their running shoes. Be sure to rotate your running shoes to minimise injuries too.

Reference

Malisoux L, Chambon N et al (2016). Influence Of The Heel-to-Toe Drop Of Standard Cushioned Running Shoes On Injury Risk In Leisure-time Runners. A Randomized Controlled Trial With 6-month Follow-up. AJSM. 44(11): 2933-2940. DOI: 10.1177/0363546516654690.

Now, this is what I'll call a racing flat

Patient With "Shoulder Tendinitis" Not Better After Medication

Can you guess what's wrong with my patient's shoulder?

Just by looking at the picture above, can you guess which shoulder was giving my patient problems? I also showed the picture to some of my staff and asked them "what can you see from this picture?"

Alright, for those who can't tell, here are some more clues. My patient came in with some neck pain and a very uncomfortable shoulder. He had seen his family doctor who told him he had tendinitis in his shoulder and gave him some NSAIDS (non steroidal anti inflammatory drugs).

However he did not get much better with the medication. He still had some neck discomfort and couldn't raise his arm above shoulder height. Lying on his affected side made his shoulder worse and he could only sleep supine.

At first I too thought the shoulder pain was referred from his neck. He mentioned that there was slight tingling sensation in his fingers occasionally too (which was why I thought the problem was coming from his neck). However I changed my mind after seeing he had trouble even lifting his arm sideways above shoulder height.

I told him that he probably had a tear in his L Supraspinatus muscle. If you look at the picture above carefully, you will see a hollowing above his left shoulder blade. There is also wasting in the muscle (or muscle atrophy) around the part where his neck on the left connects to his shoulder.

I was told later after an ultrasound scan that he had a full thickness tear in his left Supraspinatus muscle with retraction of the tendon! The doctor referred him for an MRI and said he may need surgery to repair the retracted tendon.

By the way, scientists have assessed biopsies from both people and animals with supposed tendinitis and found very few signs of inflammation in the tendons.

NSAIDs are commonly prescribed to reduce pain and inflammation of tendinitis. So if there is no inflammation, the medication is not going to help.

So the word tendinitis with the suffix "itis" means inflammation is misnamed since the condition has little or no inflammation. Researchers prefer the term "tendinopathy" meaning damaged or degenerating tendon.


Reference

Warden SJ (2009). Prophylactic Misuse And Recommended Use Of Non-steroidal Anti-inflammatory Drugs By Athletes. BJSM. 43(8): 548-549. DOI: 10.1136/bjsm.2008.056697.

Physio And Sports Solutions Lunch 2016

Both our clinics came together to have lunch today at the Straits Kitchen restaurant in Hyatt hotel today.

This is our biggest turn out ever and a big thank you to all our staff and their familes/ loved ones who came. For those who were not feeling well or were travelling, well, here's what you missed.

Waiting for the start

We had quite a few tables

Guess who ate this for first round?

Guess who's the best eater?

Trying to fit everyone in the picture

Hands-free Mobile Phone Drivers Roughly The Same As Drunk Drivers

Posed picture of me using mobile phone while driving

I'm sure you've seen lots of drivers driving and using their phone at the same time. I saw three drivers using their phones while standing at the back door of our clinic this morning, According to Singapore Traffic Police figures, at least eight drivers were caught using their mobile devices behind the wheel last year. Hopefully, you're not one of them.

Here's an article I found by a group of researchers comparing the effects of a variety of mobile phone usage conditions to different levels of alcohol intoxication on driving performance and vigilance.

Each participant had to complete a simulated driving task on two days, separated by a week's break. Driving performance was assessed by variables including time spent speeding, braking reaction time, time driving in target speed range, lateral lane position and speed deviation etc

On the mobile phone day, the participants performed the simulated driving task under the following four conditions. No phone usage, a hands free conversation, a hands free but cognitively demanding conversation and texting.

On the alcohol day, the participants performed the simulated driving task at four different blood alcohol concentration levels (BAC), 0.00. 0.04, 0.07 and 0.1.

Here's what they found. Under BAC 0.7 and 0.1 alcohol conditions, the participants spent less time in the target speed range, more time speeding and took longer to brake than in the 0.00 condition.

While using their mobile phones, participants took longer to brake in the hands free conversation, cognitively demanding hands free conversation and while texting. They also spent less time in the target speed range and more time speeding in the cognitively demanding hands free conversation and while texting.

When comparing both conditions, the hands free conversation was comparable to the legally permissible BAC level (0.04). The cognitively demanding and texting conversations were similar to the BAC 0.07 to 0.1 results.

According to the conclusion by the authors, simple hands free conversations while driving may not represent a significant driving risk (comparable to legally permissible BAC levels). Cognitively demanding hands free conversation and especially texting while driving represent significant risks to driving i.e. similar to when they were drunk!

In Singapore, it is currently illegal for drivers to hold any type of mobile device while driving. As long as you're holding it while the vehicle is moving you can be charged. Previously, you could not call or text on a mobile phone.

However, it is not illegal to use a mobile device if it is mounted on a holder or a dashboard. Wearable technology such as Google Glass or the Apple watch is not mentioned though.

So be safe while you're out on the roads (especially if you're cycling).

Reference

Leung S, Croft RJ et al (2012). A Comparison Of The Effect Of Mobile Phone Use And Alcohol Consumption On Drving Simulation Performance. Traffic Inj Prev. 13(6): 566-574. DOI: 10.1080/15389588.2012.683118.

Riding with one finger and giving cyclists a bad name

*Picture by Comrade King from Flickr.