Overuse Injuries in Cycling

Fondo Clinics Training
 
Cycling is an activity with high levels of participation and is growing in popularity.  The rise in popularity spans the range from cycle commuting for convenience and environment to increase participation in endurance cycling events such as Fondo events. From a community perspective there is a push to increase safety issues around cycling with bike lanes and specific bike routes.  From a health perspective, cycling is one of the beseeched “non impact” forms of cardiovascular exercise. For those who have experienced issues with knees and hips, often cycling is a relatively innocuous activity compared to higher impact forms of exercise. 
 
Overuse injuries in cycling are related to monotonous loading and maintenance of static postures for extended periods, most commonly associated with traditional road cycling. Often the fit of the traditional road bike is focussed on muscle recruitment and aerodynamics with less concern for rider comfort.  
When one compares overuse injuries to traumatic injuries in cyclists, studies indicate overuse injuries account for 50 to 60% of cycling injury presentation.1  This is consistent across recreational and elite cyclists. Recreational cyclists tend to report higher incidence of neck and shoulder pain compared to elite cyclists which may be explained by poor bike fit and failure of tissues to adapt to load.  Overall, knee pain leads to the most time missed from cycling followed by back pain. 
 
The majority of knee complaints are related to the patellofemoral joint, between the kneecap and thigh bone.  However, there are a range of other sources for pain including the knee joint itself, iliotibial band syndrome (ITBS) and infrapatellar fat pad impingement.  Although it is thought that overt tendon issues are generally less prevalent in cyclists, pain can also arise from the quadriceps or patellar tendons themselves.  Various biomechanical issues may play a role in the development of anterior knee pain in cyclists, including the way the patellofemoral joint is moving through the pedal stroke and various levels of torque applied to the knee joint. These issues can be altered by intrinsic and extrinsic factors.  Intrinsic factors include biomechanical variables such as gluteal and quadriceps muscle strength and recruitment.   The glutes (buttock muscles) and quads are the power behind the pedal stroke. If the glutes are sluggish or weak, with increase loading, the quads take on the lion’s share of the work. This can lead to overload of the patellofemoral joint with increasing compressive forces between the patella and the femur. Extrinsic factors consist of issues such as bike fit and training error.  There is an abundance of information and opinion around bike fit and its role in overuse injury.  It has long been thought that seat height can impact anterior knee pain.   Studies have shown that lower saddle height can increase forces across the patellofemoral joint and therefore increasing saddle height in response to knee pain is a common recommendation.2 Additionally, the fixed position of the foot can have a negative impact on the optimal biomechanics of the patellofemoral joint.  This led to the advent of “float” to cleated pedals allowing for a more natural axial rotation during the pedal stroke.  There has not been any published evidence that floating pedals directly reduce injury, however they are widely accepted in the recreational and elite cycling community. 
 
Fluctuating low back pain has been accepted to be a natural part of road biking. There is some evidence that cyclists with ongoing low back pain tend to hold a more fixed position of trunk flexion while cycling than those without low back pain. This static flexion positioning can be secondary to intrinsic factors such as hip girdle and core weakness and inhibition.  Additionally, biomechanical variables can be involved, including clinically significant leg length discrepancy and diminished joint range of motion secondary to osteoarthritis or injury.  Intrinsic solutions include guided strengthening and undertaking a more relaxed position of the pelvis and low back. Extrinsic management includes a lower saddle height, increasing the handlebar height and altering the overall reach.  All of these variables will help the rider assume a more relaxed and comfortable bike position. 
 
Often injuries can be attributed to “training error” which simply means too much too fast or in more scientific terms load exceeded capacity.
Tissue capacity is the quantity of load that a tissue can tolerate before breaking down. Tissue capacity is not static. It changes in response to many variables.  Tissue load is a function of training volume intensity, frequency and type. Activities of daily living and stress levels also influence overall load and tissue capacity. Loading tissue through exercise is healthy and typically stimulates positive change within tissues in terms of strength, structure and ability to heal.  The problem comes when load exceeds the tissues ability to adapt.
A simplified way of thinking of how injuries occur is when a load placed on a tissue overwhelms the capacity of that tissue. This situation can occur in a single instance such as a traumatic injury or over time as in a repetitive use injury. Repetitive injuries occur when the training load is increased to rapidly.  This could be in terms of frequency, mileage, intensity or specific types of workouts such as hill repeats. In order to reduce risk of injury your training plan should increase the various types of load gradually and may need to modified depending on your individual response. 
 
If you start to have persistent discomfort in an area, one can modify their activities alongside a focused rehabilitation program with a goal to maximize strength and surrounding tissue capacity.  A fundamental concept in rehabilitation from sports injury is that passive modalities such as injection, massage or acupuncture may help with pain but they don’t in and of themselves augment tissue capacity.  The role of passive modalities is in enhancing an athlete’s ability to gradually step up active rehabilitation more comfortably. 
 
For the training athlete, there is undisputable benefit in improving simple self-care strategies.  Optimizing sleep is a hot topic right now with mounting scientific evidence in several areas of sport science.  Mitigating stress and adopting a positive outlook can also enhance tissue’s ability to tolerate load. This is thought to be through various hormonal pathways. 
 
Take away messages:
Optimize your bike fit, preferably through a knowledgeable bike clinician
Follow a training plan that fits you as an individual athlete
Modify your plan and seek professional advice if you have persistent discomfort
Enhance your self-care routine through attention to sleep, nutrition and stress levels. 
 
1. 1. De Bernardo N, Barrios C, Vera P, Laíz C, Hadala M. Incidence and risk for traumatic and overuse injuries in top-level road cyclists. J Sports Sci 2012; 30:1047-1053.
2. Clarsen B, Krosshaug T, Bahr R. Overuse injuries in professional road cyclists. Am J Sports Med 2010; 38:2494-2501