Cycling — Too Much of a Good Thing Can Sometimes Be Bad
In 2010, the government (LTA, URA and NParks) announced the National Cycling Plan, aiming to make cycling a feasible transport option for Singaporeans. As cycling networks are being developed and improving connectivity between towns, it can be expected that more of us may consider cycling as a healthier, eco-friendly way of transport. With the development of park connecting trails like the Coast-to-Coast trail, Round Island Route Park Connector, and the Rail Corridor, it also seems like a good time to pick up cycling as a leisure or sporting activity.
This all sounds great, with the increasing prevalence of non-communicable diseases amidst an aging population, these initiatives provide us with more options to fulfil our need for moderate intensity aerobic exercise to maintain our cardiovascular health. As a relatively low-impact sport, it is also less likely for us to sustain injuries like stress fractures or muscle tears.
However, as the title suggests, cycling as a sporting activity does present with its own unique set of injuries, categorised mainly into traumatic injuries and overuse injuries. The former can largely be avoided with a good sense of traffic safety and caution. It is the latter that will be discussed further in this article. It is interesting to note that it is not just elite, professional cyclists who suffer from overuse injuries. In terms of prevalence, 85% of recreational cyclists in an epidemiological study (Wilber CA et al., 1995) experience an overuse injury. Whereas in elite professionals, 62% of all injuries are also due to overuse (Barrios C et al., 1997).
What then are overuse injuries, and why do they occur? Overuse injuries are due to repetitive stress to the skin, tendons, joints and nerves that are involved during cycling. They present when tissue breakdown in these structures occur faster than repair. This is compounded by biomechanical factors such as a poor bike fit. Let us now assess systematically the different types of overuse injuries in cycling by anatomical region from head to toe.
Neck and Lower back
The neck and lower back are two areas that experience a considerable amount of strain in cycling. This is largely attributed to the posture adopted by cyclists (demonstrated in the left image below) where the lower back (lumbar spine) is flexed, while the neck (cervical spine) is extended so that the cyclist can look ahead. This could be due to poor flexibility of the hamstrings, as well as handlebars that are too short. Ways to prevent strain to the paraspinal muscles in these two areas include: raising the handlebars to shorten the reach, and stretching the hamstrings to prevent excessive rounding of the lower back.
Wrists and Hands
Next, nerve compression injuries at the hands and wrists are also common in cycling. Two major nerves run their course through the wrist to the hand, namely the ulnar nerve which runs along the side of the wrist of the little finger, and the median nerve which runs down the middle of the wrist and branches out at the palm. Compression of these nerves can occur from prolonged gripping of the handlebar via the mechanisms illustrated below. The pressure exerted on these nerves can lead to temporary ischemia of the nerves, causing sensory and motor deficits to the areas of the hand supplied by the nerve. Such injuries can be avoided by using padded gloves and handlebars, changing your hand position frequently when cycling, and also by raising the handlebars to shorten the reach required.
Owing to the prolonged periods of sitting in the bicycle seat, tissues in the buttock and groin are also prone to overuse injuries. Skin chafing and ulceration is common, owing to the constant friction and pressure, coupled with the moisture frown sweating. Preventive measures include wearing padded chamois shorts, using a more cushioned saddle, as well as applying petroleum jelly to areas prone to chafing. In cases where mild chafing of the skin has occurred, it can be treated with antiseptic cream, whereas ulcerations will require wound dressings coupled with topical and oral antibiotics. In both cases, it is important to change out of wet clothing as soon as possible.
Buttocks and Groin
Like in the hands and wrists, the neurovascular structures running in the buttocks are also prone to compression injuries by being compressed between the pubic bone and saddle of the bicycle. The structures at risk are the pudendal nerve and pudendal artery, which supplies various structures at the perineum and perianal region. Symptoms from the nerve compression can last a few days after long rides and may include genital pain, a burning sensation, as well as numbness in the areas supplied by the nerve. The compression of the artery can lead to reduced blood flow to the genitalia, and in the long run, may lead to complications like erectile dysfunction. In studies conducted, it was found that erectile dysfunction presented in 24% of cyclists with a weekly mileage of more than 400km (Summer F et al, 2001), and also in 4% of amateur cyclists (Schwarzer et al, 1999). Preventive measures would involve reducing the amount of pressure that is exerted on the perianal region. This can be achieved by alternating between standing and sitting, taking frequent breaks, avoiding excess upward saddle tilt, as well as investing in ergonomic saddles.
Injuries to the knee can be classified into those of the outer knee, and those at the front of the knee. In the outer knee, iliotibial band syndrome can occur. The iliotibial band is a thick band of fascia originating from the gluteus maximus and the tensor fascia lata connective tissue, extending from the pelvis to the Gerdy’s tubercle (a bony prominence below and outside the knee). With repeated flexion and extension of the knee during cycling, there can be excessive friction of the iliotibial band against the lower outer part of the thigh bone (the lateral femoral epicondyle), causing irritation and inflammation of the band. This can be attributed to a rapid increase in training volume and intensity, inward-pointing toes when cycling, and a tight iliotibial band. Treating iliotibial band syndrome can be approached firstly by reducing training volume, pointing the toes straight forward whilst cycling, and also by stretching and foam rolling the iliotibial band to improve its flexibility (see images below).
Pain at the front of the knee can be due to patellofemoral pain syndrome. This describes a misalignment between the kneecap (patella) and the thigh bone (femur), causing excessive pressure on the kneecap during knee movements such as the repetitive flexion and extension during cycling. Patellofemoral pain syndrome can occur in cycling due to reasons such as a low saddle height, weak thigh (quadricep) muscles, as well as a tight iliotibial band. Treatment of this pain would involve addressing the above mentioned factors by raising the saddle height, stretching the iliotibial band, and strengthening the quadriceps and core.
Last but not least, foot pain and numbness is also one of the many symptoms in overuse injuries related to cycling. This is known as metatarsalgia, and is caused by irritation and compression of nerves and tissues around the ball of the foot. This can stem from faulty weight distribution on areas of the foot, and is exacerbated by poorly cushioned insoles as well as wearing shoes with narrow toe boxes or excessively tight straps. It is advisable for cyclists to use metatarsal pads, wear shoes with a wider toe box, and/or loosen the shoe straps.
In light of the Covid-19 pandemic, we would also like to remind cyclists to cycle alone if possible and maintain safe distancing guidelines. Do also maintain personal hygiene by wiping perspiration on your face with a towel rather than your hands, wearing a mask if possible, and washing your hands after cycling. Lastly, avoid touching public objects and cycling itself if you are feeling unwell.
This article has explored, by anatomical regions, common overuse injuries related to cycling, as well as ways to prevent or treat these injuries. Whilst cycling is a great form of exercise, it is important to understand them so that we can continue enjoying this activity without having to give it up to such preventable overuse injuries. To sum up, to avoid and prevent cycling related injuries, it is crucial to have a proper bike fit, increase mileage and intensity gradually, and have adequate rest. Happy cycling and cycle safely!