Treatment and Avoidance of Cycling Sports Injuries

The Biomechanics of Bike Set Up and Avoidance of Cycling Injury

In 2003 I was lucky enough to have the opportunity to venture into the Pyrenees mountain range in the south of France to witness the penultimate mountain stage of the Tour de France. It was one of the greatest stages in recent years, when Lance Armstrong fell off his bike in the final ascent only to remount, attack and put the winning time on Jan Ullrich to clinch his fifth consecutive tour victory. I had been out to see the tour before, but it wasn’t until I was on that mountain that the passion and fanaticism surrounding the sport of cycling blew me away. Injury to any cyclist with even the smallest amount of the commitment I saw on the mountain that memorable day would be devastating.

Cycling knee pain sports injuries treatment

Fortunately, in the sports injury world cycling injuries are more often a benign force than a cause of trouble. Because it is low impact, at The North Wales Spine Clinic we encourage patients to get on a bike as it provides many people who otherwise would struggle to perform regular exercise with the chance to stay healthy and active. The UK government launched the Bike to Work scheme a number of years ago and I was in the fortunate position to help both the Royal and Sun Alliance and the Royal Bank of Scotland employees benefit from this opportunity. Although we treat many types of sports injuries at The North Wales Spine Clinic we are cyclists and cycling sports injuries are something we see a lot of in the Conwy, Gwynedd and Anglesey areas due to the increasing popularity of the sport.

Acute Cycle Injury

Because cycling is such a widespread leisure activity (and bicycle ownership almost endemic), injury statistics are not hugely informative. US figures, for instance, estimate that 85 million Americans are cyclists; and of these 540,000 end up in hospital accident and emergency departments each year. Among the casualties, 67,000 have head injuries and 600 die (1).

For any competitive cyclist, to train on the road is to accept the risk of serious injury, because of the twin hazards of vehicle traffic and speed. A multitude of orthopaedic injuries occur with high-speed accidents, but of most concern are head injuries. As a result of fatal injuries during competitive cycling, the compulsory use of helmets has been in place for a number of years at the Tour de France, except for the finishing climb in the mountain stages. In Australia and New Zealand, all cyclists (from everyday users to pro competitors) are required to wear helmets or face hefty fines. Throughout Europe, by contrast, there is no such compulsion. Despite legislation and campaigns promoting awareness of cyclists to other road users, acute injuries in cycling will always be a big concern for those participating in the on-road sport.

Chronic Injury

Several studies highlight the neck and back as the main sources of overuse sports injuries. After a six- to eight-day cycling tour for recreational cyclists, Wilber et al reported that 54.9% of females and 44.2% of males presented with neck pain for medical treatment, and 30% of both males and females with back pain (2). Patterson et al (3) analysed nerve palsy in the arm– often referred to as ‘cyclist’s palsy’ – after a 600km bicycle ride. Of the 25 riders given physical and questionnaire assessments, 23 had either muscular or sensory symptoms (pins and needles, pain or numbness). Most symptoms were reported in the hands in the ulnar nerve distribution (inside edge of elbow and forearm).

Wilber et al (2) found 85% of cyclists suffering with one or more overuse sports injuries: 48.8% had neck problems, 41.7% had knee trouble, 36.1% groin and buttocks, 31.1% hands and 30.3% backs. The study also found that female cyclists are approximately 1.5 times more likely than males to develop neck symptoms. Although neck symptoms are the most common, in my experience knee injuries are of more concern, as they pose a greater long-term risk.

Biomechanics

A single pedal cycle involves a power phase from 12 o’clock to 6 o’clock and a recovery phase from 6 o’clock to 12 o’clock. The power phase delivers most of the force that generates forward momentum. (Fig 1.) This force is produced via the extensors of the lower limb chain: quadriceps, glut max, hamstrings (working at the hip) and calves (working at the ankle). The recovery phase also contributes to overall power delivered in one cycle by the upward pull of the attached shoes via the flexors: hip flexors, hamstrings (working at the knee) and calves (working at the knee).

At 12 o’clock, the knee is flexed to 110 degrees and then extends 75 degrees through the power phase to 35 degrees flexion at the beginning of the recovery phase. It is important to note that during the power phase the knee will drift inwards because of the normal internal orientation of the femoral condyles or top part of the knee joint (more pronounced in females).

The foot pronates (arch flattens) during the power phase, imparting an internally rotating force to the knee, much the same as during the stance phase of running, thereby increasing the stress to the inner side of the knee. The opposite happens during the recovery phase in preparation for another power phase. At the bottom of the power phase the foot should be parallel to the ground. The lumbar and thoracic spine has to tolerate prolonged flexion and the cervical spine prolonged extension.

North Wales Sports Injury Treatment

Fig. 1. Muscles used in the pedal cycle

Assessment & treatment of chronic sports injury

When a cyclist presents for treatment with an overuse sports injury, at The North Wales Spine Clinic we look to gain an understanding of the following areas to determine the underlying cause:

  • The athlete’s anatomical alignment
  • Musculoskeletal function or kinetic chain
  • Bike set-up
  • Training history and changes in regime

For each sports injury, we need to be aware of the relevant flexibility and muscle balances in order to establish technique faults contributing to injury (for instance, the cyclist may be inwardly deviating with the left knee or the pelvis may be dropping to the right when the right foot reaches 6 o’clock). This framework helps us provide a feasible treatment protocol for cycling sports injuries.

Bike Set-Up

Correct bike set-up is crucial to maximise performance, avoid sports injuries and treat existing sports injuries. However very few recreational cyclists are aware of this. If you venture on to the roads in Conwy, Gwynedd or Anglesey on a Sunday morning, you will see droves of cyclists with their seats set too high or their knees grossly deviating left and right.

Often the bike shop owner will set the bike up for customers and in using a few rules of thumb (front hub obscured by bars when seated, 900 knee angle at 3 o’clock position) and this is usually sufficient for the casual rider. However for the more regular rider this ‘one size fits all’ approach is not detailed enough and the specific biomechanics of the rider are not taken into account.  Over time this can lead to a sports injury.

Bike set-up can be assisted greatly by two small pieces of equipment: full shoe-length leg raises compensate for leg-length discrepancies, and forefoot wedges placed between the cleat and shoe correct knee alignment by allowing the foot to operate in its normal position. Specific cycling orthotics are also commonly used.

The cyclist also needs to be made aware that they should adjust their bike set-up to suit variables such as the length of race or competitive goal in order to achieve the best balance of efficiency and comfort. In endurance races, the rider will usually opt for a slightly less aerodynamic position to improve comfort, whereas for a short time trial, the tightest possible aerodynamic position and lowest trunk position will deliver maximum speed advantage.

Table 1 below sets out some of the more salient issues when achieving optimal bike set up.

(The cleat is a plastic piece screwed into the bottom of the shoe to enable the rider to clip into the pedal.)

Table 1: Features of bike set-up

Key position

Where to adjust

At 3 o’clock the frontal aspect of the kneecap should line up with the centre of the pedal axle
  • Saddle position: move the saddle forward or back
  • Adjust seat height
  • Cleat position: adjust forward or backward on the shoe
At 3 o’clock, the centre of the kneecap should be directly in line with the centre of the pedal when looking from the front
  • Cleat position: the cleat can be rotated depending on the rotational position of the foot relative to the lower leg
At 6 o’clock, the knee should be flexed to 30-35 degrees
  • Adjust seat height
1.     Length between seat and handlebars

2.     Height of handlebars

Both settings should allow a comfortable position through the upper trunk, relaxed position on the saddle and be as aerodynamic as possible

  • Frame: length of top tube (from seat pole to headset) must be correct at purchase of bike
  • Stem (connecting the frame and handlebars): adjust length and angle to vary height of handlebars

Chronic Injury Risks

When pedalling, the largest force produced acts through the knee up to 5,000 times an hour, so it is no wonder that the slightest incorrect distribution in load can end up in a serious knee injury and pain.

Table 2 below summarises the main injury risks.

Table 2: Cycling injury risks to the knee

Area of knee

Injury

Special notes

Front

Anterior knee pain, variety of causations. (Patellofemoral pain syndrome)
  • Excessive inward drift of the knee during the power phase (very common)
  • Weak anchor or core for control of the lower limb (usually the actual cause)
  • Seat set too low, can increase compression through the joint
  • All anterior knee pain can relate to the first two points
Chondromalacia (damage to articular cartilage under the kneecap)
  • A progression of above involving breakdown of the cartilage
Patellar tendinosis (inflamed patella tendon)
  • Excessive lateral traction of the kneecap (usually due to weak control of the femur at the hip – Core again!)
Quadriceps tendinosis (inflamed quadriceps tendon)
  • Not very common but tends to affect the lateral aspect of the tendon

Outside edge See Video Below

Outside edge knee pain (Iliotibial band (ITB) friction syndrome)

No1 Cause of knee pain for cyclists

  • Excessive pressure on the ITB as it passes over the outside of the knee
  • Can relate to incorrect bike set-up that increases the stretch on the ITB: saddle too high or too far back
  • Leg length discrepancy: increased stretch on ITB in the shorter leg
  • Excessive lower leg internal rotation, which increases the pressure between the outside of the knee and the ITB. Can be anatomical or related to positioning of the cleat
  • NOTE: ITB is always overactive (tight) with poor core control
Inside edge Pain on the inside and slightly lower than the knee joint

(Pes anserinus bursitis- inflamed bursa at hamstring tendinous insertion)

  • Excessive traction of the tendon over the bursa
  • Externally rotated lower leg position, anatomical or related to cleat position
Mediopatellar plica syndrome (inflamed thickened knee capsular fold)
  • Not very common, but can impinge on the top half of the knee joint during knee flexion
Back Biceps femoris tendinosis (inflamed hamstring tendon insertion)
  • Saddle too high or too far back increases stretch on hamstrings
  • Excessive lower leg internal rotation increases stretch on hamstrings

Video – IT Band Pain – No 1 Cause of Knee Pain for Cyclists

Ongoing soft tissue massage, spinal manipulation, trigger point work and mobilisation for the hip flexors, quadriceps group and gluteus muscles are all very important, as is maintaining patellofemoral (kneecap) joint mobility. Activation and strengthening of glute max should be included where necessary in conjunction with a corrective training regime.

Sports Injuries causing Neck and Back Pain

Neck pain usually relates to the prolonged time that cyclists spend in an extended position. Constant compression of any joint over a long period can lead to the transmission of painful stimuli; restricted spinal segments, irritated nerve roots, muscle fatigue and trigger points will lead to further joint compression and chronic pain. Any prolonged position will also result in cumulative tensile stress on joint capsules and ligaments, which can bring both pain and long-term structural changes to the mobility of the spinal joint.

Cervical extension with shoulders in a depressed position increases neural tension, which can be exacerbated by handlebars set too low or the cyclist failing to keep their elbows slightly bent. Excessive or prolonged traction to the nerves can result in severe nerve root irritation causing referred symptoms into the arms. This will present as pain, numbness or tingling in the nerve distribution.

To prevent the build-up of tension, the cyclist must learn to do regular cervical flexion movements, lateral flexion and shoulder shrugs on the bike, as well as sitting upright from time to time. Treatment of this condition focuses on ensuring adequate thoracic spine mobility, first rib mobility and flexibility in cervical and shoulder muscle complex. If left to manifest for too long, surgery may be needed to widen the nerve space.

Lower back injuries are very similar in principle to neck pain in cycling, except that the aggravating position is prolonged flexion. Restricted spinal joint motion in the lumbar spine, muscle fatigue, chronic tension to posterior vertebral ligaments and prolonged compression to intervertebral discs can all be responsible for ongoing back pain. This may begin as intermittent issues but often quickly progresses into recurrent chronic back pain that can begin to affect other aspects of the cyclist life such as work and home life.

The cyclist’s pelvic position during riding is also significant. Sitting in a posteriorly tilted position increases lumbar flexion, so we may look to achieve a more anterior position through your pelvis. This should be addressed when assessing bike set-up and cycling technique.

As cyclists build up their training volume, they often suffer from aches in the neck, mid or lower back, because of the lengthy periods for which they maintain their flexed trunk position. This is normally a matter of building up their tolerance, during which time we ensure that any joint stiffness or muscle tightness is attended to. For any cyclists intending to build up to a high weekly mileage, the training should be gradual and structured.

As with all postural problems, whether on a bike or not, core stability function is crucial. Regular exercises focusing on muscle endurance should be an integral part of treatment and prevention. Postural exercises for scapular retractors, and especially lower trapezius activation, are essential to minimise neck problems. The lumbopelvic stability muscles not only have to tolerate prolonged flexion but also to continually stabilise the lumbar spine and pelvis to provide a stable platform for the major force- producing muscles. Core stability exercises for the lumbopelvic area are therefore crucial in the treatment and prevention of lumbar spine pain, especially for any cyclists increasing training volume.

Good hip flexibility also matters greatly, to relieve pressure on the knee and lumbar spine. The hip during cycling always remains in a relatively flexed position, so chronic tightness through the muscles on either side of the upper leg is very common. This can also lead to hip and groin problems such as greater trochanter bursitis or hip tendinopathies. All cyclists should perform regular mobility exercises and do trigger point work on these areas using foam rollers. Gluteal and hamstring range also needs to be maintained to be able to sit comfortably in lumbar flexion and to avoid falling too far into posterior tilt. Bear in mind yanking at hamstrings and quads has been shown to cause damage to muscles and tendons so we no longer promote static stretching. Cyclists need to facilitate the opposite muscle group through corrective exercise. Despite the continued amateur advice in cycling magazines and some ‘stone age’ practitioners still recommending static stretching there is no robust evidence that shows pulling on muscles will change their length so my advice is don’t do it. Although a relatively high incidence of hip and groin pain is recorded, my own experience is that, as with many sports, much of this is related to the lumbar spine and pelvis.

Cyclists are also at risk of urogenital problems, such as erectile dysfunction and infertility, mainly affecting those who put in large training volumes. Pudendal neuropathy is the most common presentation, caused by compression of the pudendal nerve against the pubic bone. Statistics range from 50% to 91% of cyclists reporting symptoms (4). A change of saddle to one with an increased width or padding, altering the tilt of saddle and using increased padding in the rider’s cycling shorts may all help to relieve the pressure.

Summary

If you suffer from bike related sports injuries and need treatment we specialise in bike related problems.  At The North Wales Spine Clinic we perform full kinetic chain (Human movement) assessments, have a bike fitting service for our patients and provide bespoke in depth cycle specific exercise and treatment regimes to help keep you injury free and performing at your best whilst on and off the bike.

Reference

1.    www.bhsi.org/stats.htm – bicycle helmet statistics

2.     Wilber CA, Holland GJ, Madison RE, Loy SF, ‘An epidemiological analysis of overuse injuries among recreational cyclists’ Int J Sports Med 1995 Apr;16(3):201-6

3.     Patterson JM, Jaggars MM, Boyer MI ‘Ulnar and Median nerve palsy in long-distance cyclists. A prospective study’ Am J of Sports Med 2003 Jul-Aug; 31(4):585-9

4.     Leibovitch I, Mor Y ‘The vicious cycling: bicycling related urogenital disorders’ Eur Urol 2005 Mar;47(3):277-86

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