New Updates On The Effects Of Prolonged Sitting

All on screens while sitting

I first wrote about the ill effects of sitting or being an active couch potato back in 2014. Subsequently, there were more and more research about the negative effects of prolonged sitting, suggesting that sitting is the new smoking. There were also suggestions that not all sitting is bad.

Previously, most of the data suggested that these effects were independent of your exercise habits. Even the fittest people were at risk of heart disease if they spent large amounts of their time sitting in front of desks or watching television.

Now, this is not prolonged sitting

One suggested reason why prolonged sitting is bad is that there is reduced blood flow to your legs. Your blood vessels become stiffer and less able to expand and contract in response to changes to your blood flow. Over time, that makes you more prone to atherosclerosis - a hardening and narrowing of your arteries, leading to heart disease.

Time for an update. New published research from Japan (Morishima et al, 2020) suggests that endurance training might well have some protective effects. There seems to be some differences between the current and previous study.

In the current study, the researchers studied a group of competitive cyclists versus a control group that did no endurance exercise. Before exercise and three hours later, there is almost no change in the blood flow to the legs of the competitive cyclists while it dropped by half in the matched controls.

Previously, another recent study by Garten et al (2019) that showed that endurance exercise had no protection for trained athletes. If you examined the data more carefully, you will notice that the "trained" group had an V02 max of around 50 ml/kg/min. This level is above average for young adults but not fantastic.

Nah, I'm not one of the cyclists in that study

In the latest study by Morishima by et al (2020), the competitive cyclists had an average V02 max of 61 ml/kg/min. This is considered excellent, and they have been training for five years and rode an average of 600 km per week.

The earlier study assessed micro vascular function in the subjects. This refers to the function of smaller arteries that branch off the big arteries and go into the muscles. The current study measured macro vascular function, this is the function of the big arteries from the heart to various parts of the body.

Both forms of vascular function are important. The responsiveness of the big arteries predict your risk of atherosclerosis, while the smaller arteries dictates how quickly and effectively oxygen rich blood goes to your muscles. This is really important for all athletes.

Possibly this may suggest that all the endurance training at a high level protects you from macro vascular function, but not micro vascular function during prolonged sitting. This is good news for your long term health.

However more specific research is needed, so train hard and at the same time try not to sit too long at work or at home watching Netflix. Hopefully with the circuit breaker ending in a few days time, you'll get out to exercise more often.

References

Garten RS, Hogwood AC et al (2019). Aerobic Training Status Does Not Attenuate Prolonged Sitting-induced Lower Limb Vascular Dysfunction. App J Physiol Nutr Metab. 44(4): 425-433. DOI 10.1139/apnm-2018-0420.

Morishima T, Tsuchiya Y et al (2020). Sitting-induced Endothelial Dysfunction Is Prevented In Endurance-trained Individuals. Med Sci Sp Ex. DOI: 10.1249/MSS.0000000000002302.

Great day to go cycling - Mount Faber

Physical Activities Does Not Wear Out Our Spine

I've written more than five other posts on our back / spines recently, well here's another article to align with our Instagram and Facebook posts this week. You can watch the three videos here.

We've all been sitting a whole lot more, myself included during the circuit breaker. Here's what research is suggesting, that it is actually physical inactivity and not physical labor that is associated with degenerative (or wear and tear) changes in the thoracic and lumbar spine.

The researchers studied 385 subjects on the relationship between short and long term physical inactivity and degenerative changes of the thoracic and lumbar spine over a period of 14 years. They grouped the subjects into those who did no physical activity, or did so irregularly for 1 hour a week, regularly for 1 hour a week, or regularly for more than 2 hours a week.

In addition, physical labor, walking and cycling were investigated additionally.

Correlations between physical inactivity and thoracic and lumbar disc degeneration were analyzed after accounting for sex, age, Body Mass Index, hypertension, diabetes and back pain.

Subjects with disc degeneration in the thoracic and lumbar spine were more common in those with no physical activity, irregular activity < 1 hour compared than those with regularly activity > 1 hour or more a week.

You'll be happy to know that there was no obvious significant association statistically for subjects who did physical labor, walking or cycling with disc degeneration.

The researchers concluded that physical inactivity over the 14 years they studied demonstrated a strong correlation with disc degeneration of the thoracic and lumbar spine.

Just like we wrote previously that running more miles does not wear out your knees, being active, doing physical labor will not wear out your spine too.

Keep moving.


Reference

Maurer E, Klinger C et al (2020). Long-term Effect Of Physical Inactivity On Thoracic And Lumbar Disc Degeneration- An MRI-based Analysis of 385 Individuals From The General Population. Spine DOI: 10.1016/j.spinee.2020.04.016


My boys wanted the same picture as me, so here's my older boy.

And here's my younger boy below.

Studying With Tom Myers Live Online

Looks like I've gotten myself much more screen time again during this circuit breaker period. I've signed up for a 'live' webinar taught by Tom Myers from May 15-17. Due to the unusual circumstances of the global pandemic, the course has to be taught over Zoom, of course.

This is actually the 3rd online course he's teaching since the COVID-19 started. I didn't sign up early enough for the first two and they filled up quickly. Due to high demand, they announced that Tom was teaching the same course for the third time, so I made sure I signed up straight away.

I've attended a few of the Anatomy Trains courses already, and previously one introduction course taught by Tom before. But when Tom is teaching, I just couldn't resist, even though I've learnt some of this material previously.

Tom says he misses using his hands during this pandemic

There's a slight hitch though. The course is taught from 10 pm to 12 am and from 3 to 5 am. I'll have to find a way to cope.

Picture of healthy fascia above.

What Supports The Medial Arch

I've been trying to keep myself busy during the CB and catch up on my reading and watching. Not watching Netflix, mind you. I don't have a Netflix account. At the risk of sounding like a dinosaur, I have never watched anything on Netflix.

Anyway, I've been trying to learn about the human body and how to best treat it when it's under duress. So here's sharing what I've learnt about the medial (or inner) arch and also by putting whatever I've learnt down, I can always refer back to this.

The human medial arch has a four muscles supporting it. Namely, Tibialis Anterior, Tibialis Posterior, Flexor Flexor Digitorum Longus  and Flexor Hallucis Longus (the last 3 are also known as Tom, Dick and Harry).

Back of R leg

Tom, Dick and Harry start from the back of the leg as seen in the picture above. Flexor Hallucis Longus (FHL), or Harry goes under the talus to the bottom of the big toe. This muscle carries the whole weight of the body while we push off while walking. This is also the same muscle that can cause bunions, as it puts undue pressure between the sesamoid bones under the big toe. But that will have to be another much longer post.

FHL goes in between the sesamoid bones under the big toe

I'm especially fascinated with the Tibialis Posterior muscle, especially how it attaches at the bottom of the foot in the picture below. See how wide and diverse the attachments are. It attaches to the calcaneus, the navicular bone, the 2nd - 4th metatarsals and also the cuboid.

Bottom of R foot

Other than the muscles, there is also the plantar fascia, helping to support the medial arch. Much more important than the muscles are the deeper arch support consisting of the Long Plantar Ligament (which attaches to the base of metatarsals and cuneiforms) and especially the Spring Ligament.

a = plantar fascia, b = long plantar ligament

The spring ligament is also known as the calcaneonavicular ligament (c in the picture above). It goes from the sustentaculum tali to the talus. It really acts like a trampoline to prevent your talus from flattening when you weight bear. This is most important for lifting or supporting our arches.

Typically, when we talk about arch support, we would think of taping the arch, changing our shoes, putting arch supports or orthotics into our shoes. But as you can see from the picture above that none of them can really help the spring ligament in supporting our arches.

We can really only affect/ or treat the muscles and the plantar fascia. Remember this. You may not need to buy anything fancy to support the spring ligament.

Another look at the dissected medial arch. 9 is the Long plantar ligament, 10 is the plantar fascia and 11 is the spring ligament.

Now you know.

Tiger Woods Blames Running For "Destroying" His Body

I came across this article from Runner's World and the video here recently saying that Tiger Woods blamed running for his decline in golf.

Tiger Woods turned pro at age 20 (in 1996) and revolutionized how golf was played. He trained really hard physically and many others copied his physical training regimen (after seeing his success) in order to catch up. He made golf really, really popular. Lots of young local golfers I treated wanted to be like him.

Many courses had to "Tiger-proof" their course by adding yardage to their tees because of his long hitting ability.

Well, with all due respect to Tiger, I don't think it's fair at all that he attributed all his injuries to running over 30 miles (or > 48 km) a week over six years.

Yes, Tiger had numerous knee surgeries after tearing his Anterior Cruciate Ligament (ACL) and at least four back operations.

I would say that his injuries were definitely partly due to his ability to hit the ball so far. The fact that he generated so much forces with his hard hitting that it affected his left knee and back.

Stand up and try this now. If you are right hand dominant, when you rotate your body to hit the ball, you can feel the rotational forces though your left knee and back. For Tiger fans, here is another possibility.

I've written before that running more miles does not wear out your knees. Plenty of published evidence support those findings. Done correctly, running is actually good for your back.

And the stress from his "personal affairs" definitely did not help either.

So don't worry, if you do not have any pre- existing injuries, running more than 30 miles (48 km) a week will not "destroy" your body or knees.

Can Exercise Give You Headaches Or Migraines?

My patient rings up complaining of having a terrible migraine after going out for a run. She suffers frequently from migraines and usually exercise and/or seeing us in the clinic would help. She was hoping to come and see us since Physiotherapy has been reclassified as "essential services".

Despite Physiotherapy being reclassified as an "essential service" recently on 29/4/20, the criteria to see patients in the clinic are very strict.

The Ministry of Health (MOH) have told us that face to face sessions are only for "patients whose condition would deteriorate significantly or rapidly if treatment is not provided or performed and would potentially threaten their health and well being".

We can only open once a week seeing a maximum of 6 patients and we're told to "leverage on tele-consult/ tele-rehab as far as possible".

Many of our patients have called or messaged us asking to be seen and we've explained that we can only treat them if they meet the above criteria.

My running patient did add that she ran a lot harder and that was when her migraine started. I told her that I just read an article on runners and their calcitonin gene-related peptide (CGRP) levels.

In that study, 46% of the enlisted running subjects reported suffering from headaches/ migraines while 54% did not.

CGRP helps with making your blood vessels larger (vasodilation), which then increases blood pressure and inflammation in your nervous system. Increased CGRP levels are known to be associated with headaches and migraines.

The researchers measured CGRP levels (by drawing blood) in  runners before and after running. They then got the runners to run 21 kilometres at 75-85 VO2 max.

 CGRP levels significantly increased by one and a half times in the entire group after the run. CGRP was significantly higher for those who had prior migraines before the run and those runners reported suffering from migraines after the run.

This led the researchers to conclude that medium to long distance endurance exercise boosted CGRP levels and that high intensity exercises can heighten the reaction further. This can potentially trigger both headaches and migraines brought on by exertion.

Previous research has shown that exercise can decrease frequency of migraines and improve symptoms and reduce migraine triggers (Aristeidou et al, 2018). With this new article I have to add that migraine sufferers need not stop exercising, but they do need to watch their exercise intensity.

Low to moderate exercise intensities does not seem to be a trigger. There are also medications that helps with blocking CGRP for those of you who don't mind ingesting medication in order to exercise hard. Check with your doctor for the prescription.

Good news for those who do not suffer from headaches or migraines as an increase in CGRP levels is good for you as it has a protective effect for cardiovascular function.


References

Aristeidou S, Baraldi C et al (2018). The Association Between Migraine And Physical Exercise. J Headache Pain. 19(1): 83. DOI: 10.1186/s10194-018-0902-y.

Tarperi C, Sanchis-Gomar F et al (2020). Effects Of Endurance Exercise On Serum Concentration Of Calcitonin Gene-related Peptide (CGRP): A Potential Link Between Exercise Intensity And Headache. Clin Chem Lab Med. DOI: 10.1515/cclm-2019-1337.

To all our patients reading this and asking to be treated. Yes the government has indeed allowed some businesses to open. As you can see from the MOH circular, clinics have very strict criteria regarding who we can see even though this is not published in the news. Rightfully so since we are still in the circuit breaker period.

Please bear with us, we will inform you as soon as we are given further instructions by MOH to allow us to see more patients.