Osteoarthritis and Hip Replacement Risk LOWERED by Running and Walking

Introduction

Osteoarthritis (OA) is the leading cause of disability as we get older. It affects between 7% and 25% of caucasians over 55 years of age and more common in women than men. There has long been this myth that running and other strenuous sports increase OA risk, more so than walking and less-strenuous activities. This myth is based on the fact that running causes knee injuries and damage that are both well known risk factors for OA of the knee. However, the lower body mass index (BMI) as a measure of weight for height, is known to lower the risk of knee OA. Analyses were therefore performed to test whether running, walking, and other exercise affect OA and hip replacement risk and to assess the role of body mass index (BMI) in mediating these relationships.

The Research

Data from 74,752 runners from the USA-based National Runner’s Health Study and 14,625 walkers from the National Walkers Health Study were tracked over 5.7 years in this study.  The runners and walkers were asked many questions including whether they had physician-diagnosed OA and hip replacement during that time, their height and weight to determine BMI (kg/squared meter of height), and how much exercise they did in terms of energy expenditure per day (light, moderate or vigorous).

The Results

Older age was associated with increased risk of OA, increasing by 3.9% per year in men and 6.1% in women. Risk of hip replacement increased by 7.4% in men and 10.6% per year in women. In the runners, 2004 (2.7%) reported OA and 259 (0.4%) reported hip replacements whereas 696 (4.8%) walkers reported OA and 114 (0.8%) reported hip replacements during the 5.7 years of follow-up. Compared with non-running activity in the runners, the risks for OA and hip replacement decreased as follows: 1) 18.1% and 35.1% with light intensity running; 2) 16.1% and 50.4% for the moderate intensity running; and 3) 15.6% and 38.5% for vigorous running. Baseline BMI was strongly associated with both OA (5.0% increase per kilogram per square meter) and hip replacement risks (9.8% increase per kilogram per square meter). The reductions in OA and hip replacement risk by increasing the intensity of running did not differ significantly between runners and walkers.

So What?

Running significantly reduced OA and hip replacement risk due to, in part, running’s association with lower BMI. It appears the known benefits of exercise promoting cartilage thickening and preventing loss of the viscosity and elasticity of the cartilage help prevent OA. So stay slim into older age and keep runnin!

For older athletes wanting to stay both illness- and injury-free, please read Chapters 12 (Injury prevention and management for the masters athlete) and 14 (Staying healthy and illness-free) in my book The Masters Athlete now available in pdf format online.

Source: Williams, P. (2013). Effects of running and walking on osteoarthritis and hip replacement risk. Medicine and Science in Sports and Exercise, 45(7): 1292-1297. 

Anti-Inflammatories and Sport

Hamstring Strains – Is Stretching the Answer?

Introduction

Muscle strains are common in masters runners, triathletes and team players. In running activities, this injury often occurs at the end of the swing phase, as the leg is rapidly extending before being planted on the ground. This injury can often take some time to heal and there is a high risk of re-injury. In fact, one study on elite football players reported a 30% reinjury rate.

Most of we older (and hopefully wiser!) athletes include stretching as part of our regular exercise routine as a way to prevent injuries, muscle soreness and improve our sporting performance. However, with the time pressures of work and family and our enthusiasm to just get out there and train, sometimes we omit it all together. All too commonly, we only commence stretching after an injury, when our physiotherapist or chiropractor tells us to.

The question often asked these days is: Is hamstring stretching of any benefit in preventing hamstring injuries?

Where is the evidence?

 A recent article in the Strength and Conditioning Journal sheds some light on this question. The authors describe the scope of hamstring strains, the risks of recurrence and strategies to minimise recurrence risks. Data from the US collegiate sports system reports hamstring strains to be the second most commonly reported injury. Whilst factors such as age and injury history both affect injury risk, this report provides evidence that hamstring flexibility is NOT a predictor of hamstring strain. In fact there appears to be evidence that quadriceps flexibility and quads/hamstring muscle strength imbalance are more reliable predictors of hamstring strain. More specifically, eccentric hamstring strength (the ability of a muscle to produce force whilst lengthening) is altered as a result of previous injury. It seems that the repair process of an initial injury results in scar tissue. This new tissue is relatively inelastic and non-contractile. This changes the stiffness of the muscle and its ability to produce force near terminal extension; the range of motion where recurrent hamstring strains occur. Stretching does not restore this loss of strength, however eccentric exercise may.

So What?

 There are 3 strategies you can implement to reduce the risk of hamstring strain recurrence:

  1. Dynamic warm up – this should include range of motion, running drills and low level plyometrics (skipping, hopping, jumping). Change of direction skills should be used if appropriate
  2. Core or trunk stabilisation exercises – depending on the sport, these may include Swiss ball exercises, planks or exercises in single leg stance
  3. Eccentric strength training – typically this may include Nordic hamstring exercises however low intensity single leg landing exercises, eccentric step downs, lunges, Zerchers or Waiter bow exercises may be better alternatives

Programs incorporating the above elements have been shown to significantly reduce hamstring strain recurrence. Despite this evidence, there appears to be no reason not to stretch. Almost all athletes say they feel better when they stretch and it is unlikely to reduce performance, even in sprint or power efforts.

Source: Sherry, M et al; (2011). Hamstring Strains: Basic Science and Clinical Research Applications for Preventing the Recurrent Injury. Strength and Conditioning Journal, 33(3): 56-71

Masters Athlete thanks Rob Stanton, an Accreditted Exercise Physiologist and Level 2 Strength and Conditioning Coach for contributing this article. Rob is co-founder and Director of Vector Health and has over 15 years experience in the assessment and prescription of exercise for athletes, rehabilitation and in the management of chronic disease. He is a former coach of Australian Powerlifting teams, Queensland Academy of Sport regional Strength and Conditioning supervisor and has worked with athletes from grass roots to Olympic level. Rob can be contacted by email at rob@vectorhealth.com.au

Running injuries – what does the science say about preventing them?

Shin Splints – A Pain in the Leg!

I remember them well-that dull ache at the front and side of my shins. I was 27 years old, in my prime and invincible! I’d always run pretty well and was doing 3 x 5k runs a week for health and Rugby fitness. At the time I was also a national surflifesaving champion and working as a PE teacher in Ipswich, Queensland.

I’d just heard about this new endurance event called an Aquathon – a 5k run followed immediately by an 800m swim. You run in your swim gear, kicked off your shoes and dived straight in for the swim! The national championships were being held at Oatley in Sydney. I had 3 weeks to get ready.

I’ll give that a go I thought! I’m already pretty fit. I know what I’ll do! I do interval training, everyone says it’s the way to get race fit fast!  Down to the local athletics track wearing  a pair of thin road racing shoes and into it. Warm-up with a lap easy, do some stretches and then 10 x 400m runs on 2 minutes then a lap warm-down and stretch again. Twice a week of intervals should do it on top of the normal 3 x 5k runs. And maybe a 10k run as well to get some endurance up!

Big mistake – shin splints big time! Never forgotten and never repeated! Young and dumb! So what does the research say about the causes, treatment and prevention of these very painful lower limb injuries.

Causes

Medically, shin splints are called Medial Tibial Stress Syndrome (MTSS). They are sometimes called “tibial stress syndrome”, “tibial fascitis”, or “anterior compartment syndrome”. Shin splints account for 10-15% of all running injuries and up to 60% of all the conditions that cause pain in athletes’ legs. Interestingly, women are three times more likely than men to get them, especially those who try and keep up with male training partners and have to work harder physiologically than the men at the same running speed.

While the cause of MTSS pain is unclear, most researchers agree the shin splints are related to either the covering (fascia) of the soleus muscle (see picture) connected to the covering of the tibia (shin bone) being damaged or the repetitive impact forces that fatigue the same muscle which create slight bending in the tibia bone and small microfractures in the bone.

Research has shown that there is no one cause but the proposed risk factors include: 

  1. Increased pronation of the foot
  2. “Tight” calf muscles that can lead to pronation
  3. Muscle strength imbalance between the front and rear of the lower limb with strong front of shin muscles compared to the calves
  4. Too big a jump in training intensity (in particular) or distance
  5. Training too much on hard surfaces
  6. Training too much on inclined surfaces such as hills, stairs or cambered roadsides
  7. Previous history of MTSS
  8. Genetic factors such as flat feet, high arches or leg length differences
  9. Inadequate calcium intake
  10. High body weight
  11. Having a training age of under 5 years – being relatively new to running
  12. Poor condition of shoes, especially poor shock absorption in the midsole

Looking at most of these risk factors, it becomes pretty obvious what we can do to misnimise the risk of getting shin splints.

Treatment

Rule number one, see a professional (e.g. physiotherapist or podiatrist). Ideally one that is a runner or works with athletes regularly. I’ve learnt over the years to see a podiatrist immediately I have any running issues. She is a runner herself and has videoed me side-on and from behind, looked at my foot and lower limb angles at rest, and looked at my (smelly!) shoes. She has identified some areas I need to work on to prevent any future injuries.

Non-steroidal anti-inflammatory drugs (Ibobrufen, Brufen, Nurofen, Naprosyn, Voltaren, Advil), rest, taping and ice can help the pain.

Below are some other treatment options:

  1. Decreasing run distance, frequency and duration
  2. Replacing road runs with water running or running on grass
  3. Increase the strength and endurance of the soleus muscle through heel raises on steps
  4. Replace those old shoes or get insole inserts
  5. Arch taping or taping around the area of pain
  6. Ice massage
  7. Control pronation through orthotics or new shoes suggested or designed by the podiatrist

My advice is to try these as soon as you get any pain in the the areas shown in the picture above. However, if pain persists, trot along to your runner-friendly podiatrist for professional diagnosis and treatment specific to your individual case.

Prevention

Research has shown that no single prevention method is consistently effective in managing shin splints. Interestingly, stretching of the lower legs has consistently been shown not to prevent MTSS. However, several methods have proven useful including:

  1. Shock-absorbing insoles
  2. Replacing running shoes every 400-800 km depending on body weight and training surface
  3. Pronation-controlling insoles
  4. Lose body weight
  5. A gradual and progressive increase in running intensity and volume or type (e.g. hills or intervals)
  6. Run on softer surfaces. Here is a suggested order going from softest to hardest (grass > bush trails > grass trails > cinders > synthetic tracks > treadmills > asphalt > concrete).

Listen to your body, wear well-cushoined shoes, stretch before and especially after all runs, run on flatter and maybe grassed surfaces or trails, warm-up and down well, and gradually increase the intensity, frequency and distance of your runs. If pain persists, get along to a professional – a podiatrist.

Sources:

  1. Craig, D. (2008). Medial tibial stress syndrome: evidence-based prevention. Journal of Athletic Training, 43(3): 316-318.
  2. Hubbard, T. and others (2009). Contributing factors to medial tibial stress syndrome: a prospective investigation. Medicine and Science in Sports and Exercise, 41(3): 490-496.
  3. Moen, M. and others (2009). Medial tibial stress syndrome: a critical review. Sports Medicine, 39(7): 523-546.