Injury Epidemic

Since the running boom began 40 + years ago, participation in marathon running events has risen from under 30,000 people per year to 507,000 participants per year (1). How often have you or somebody you know, signed up for a running event and became injured before race day?  As marathon participation has risen, so has running related injuries.  Sadly, the scientific literature on running injuries notes injury rates somewhere between 19-79% annually.  The spread is huge, however much of the literature considers time off from running due to pain as an injury, even when nonspecific in origin.   None the less, even at the minimum of 19%, this is far too great. Unfortunately, I have witnessed many times people running despite an injury.  Quite honestly, I am not a fan of seeing runners wearing bracing devices.  More than likely, if there isn’t an organic structural issue going on, whatever the runner is trying to band aid up could have been prevented or treated with proper run training, chiropractic, massage, gait training, and the assistance of corrective exercises. Bracing and taping often times helps symptoms in the short term, but doesn’t treat the dysfunction and will only initiate a cascade of training setbacks, creating barriers to improvement and goal achievement.
 
In addition to improper run training loading, too great intensity of running, and too little rest/recovery,  many injuries are due to poor biomechanics, such as hip internal rotation, hip adduction (the thigh bone moving towards the midline of the body), and contralateral pelvic drop (pelvic drop of the non-weight bearing leg).  Although pain exists in one part of the body, the problem can actually be from a more distant site.  I like to imagine muscle imbalances as muscles playing tug of war and the bone is actually the rope.  The body will take the path of least resistance, which means that the tighter, overactive muscle will pull the bone in one direction and the weaker opposing muscle will allow for excessive, inefficient movements.  This causes improper distribution of the ground reaction force up the kinetic chain or joint segments of the body.  
   
Safe and efficient running requires an optimal orchestration of many muscles and joint movements and their movements are referred to as internal factors related to each individual runner. Part of understanding injury, is understanding how the body responds to forces placed on it.  In the study of biomechanics I was introduced to Wolff’s and Davis’ law, which respectively state that bone and soft tissues remodel along the lines of stress. When we typically hear or read the word “remodel” we think of something nice or better. If stress or the load is undertaken in a biomechanically correct form, then the stress will be positive and it will strengthen tissues and bone.  However, with poor movements, the lines of stress will be deviated from the intended path and can breakdown tissues and bone, which would in fact be a remodel from its former or intended state, leading to dysfunction.  Running with a biomechanically correct stride has positive effects on bone.  Bone mineral density (BMD), a measure of bone mass is greater in exercised limbs as a consequence of Wolff’s law, compared to sedentary individuals (2) and females have shown an increase of 0.9% BMD per year in exercised limbs at the loading site of impact (3).  
 
I will admit, I am a bit of a nerd, but knowing this stuff is what helps me correct training errors of my runners and to help keep me out of fracture city like I experienced when I first took up distance running.  As mentioned, running is actually good for bone, but not so much if your stabilizer muscles aren’t in good working order to do just that.  There are three planes of motion that our bodies move in and running occurs in one, the sagittal plane.  I think that an error many runners make is that they neglect some of the other muscles that help support running through stabilizing in the other two planes of motion.  Only training the muscles that work in one plane is sort of like the shirtless guy you see running in a 5k with the well-defined chest muscles from his 100 push-ups a day, but as you see him from behind, his back is giggling, without definition.  I have seen this friends and it is the oddest thing. Structurally this can create issues.  Most people have heard of the piriformis and gluteus medius muscles.  These are muscles that runners commonly have issues with and guess what?  They primarily move in the other planes of motions, although the piriformis also aids in hip extension in the sagittal plane. 
   
The reasons noted above for contributing to running injuries is not at all a complete list of potential internal and external factors that contribute to injury.  However, knowing this information is a great aid in decreasing injury possibilities and building more efficient runners.  My runners that are local in San Diego County, receive a screening before starting a marathon training program with me and have proven to be informative and valuable.  I can also screen runners that train with other coaches and use other training plans.  So don’t be shy to contact me to use my services.

In a blog next week, I am looking forward to giving you the appropriate answer to the question I’m sure every runner has been asked before, ”aren’t you afraid you will get arthritis from running?”  Please feel free to message me with questions.

Fight ON!
Coach Gina

Runner Image: Christian Pratt

References:
1. Fields, K. B., (2011).  Running injuries:  Changing trends and demographics.  Current Sports Medicine Reports, 10(5), 299-303. doi: 10.1249/JSR.0b013e31822d403f.
2.  Harrast, M. A., & Colonno, D. (2010).  Stress fractures in runners.  Clinics in Sports Medicine, 29(3): 399-416. doi: 10.1016/j.csm.2010.03.001.
3.  Nevill, A. M., Burrows, M., Holder, R. L., Bird, S., & Simpson, D.  Does lower-body BMD   develop at the expense of upper-body BMD in female runners?  Medicine and Science in Sports and Exercise, 35(10), 1733-1739.