Life in Ireland always has a focus on sport. From Christy Ring (hurling), Sonia O’Sullivan (athletics), Roy Keane (soccer), Brian O’Driscoll (rugby) and Rory McIlroy (golf), to name just a few, Irish life is immersed in sport. 

However, over the years sport has changed with the advent of the professional era. This has seen many amateur sports persons and teams train and compete almost to professional levels. With this the demands of sport have increased. Unfortunately, with incorrect training methods, poor or inappropriate equipment, and a lack of programmes following sports injuries, we are seeing a growing number of sports injuries which are problematic even for our amateur sports enthusiasts. 

In this article we will focus on some of the lower limb injuries sustained by sports enthusiasts who are involved in running or a sport in which running is an integral part.

Incidence of lower limb injuries

The incidence of lower extremity injuries varies from sport to sport. For example, among runners they range from 19.4-79.3% depending on the literature.¹ Of the areas of the lower limb the knee is the most commonly injured. 

Some of the most common lower limb injuries diagnosed include: patellofemoral pain syndrome, medial tibial stress syndrome (shin splints), stress fractures of the metatarsals and tibia, Achilles tendinopathy and plantar fasciitis. Despite the popularity of running-based sports and the prevalence of related injuries, few studies have successfully identified the individual factors most responsible, suggesting that many running-related injuries are multifactorial. 

A history of prior injury is one of the few variables that has been consistently shown to increase the risk of incurring a subsequent running-related injury.² Therefore, every sports person seeking medical attention should be questioned about prior injuries, including treatments. Incomplete rehabilitation and failure to address potential risk factors associated with a prior injury increases the likelihood of recurrence. 

Risk factors

Looking at risk factors for lower limb injuries these can be divided in to intrinsic risk factors (eg. anatomic and other individual variables, including gender and BMI) and extrinsic risk factors (eg. training variables and equipment). One of the important extrinsic factors is abrupt changes in training regimens, which can contribute to running-related injuries. Although many sports medicine physicians advocate the 10% rule (ie. increase training volume by no more than 10% per week), a randomised trial of this approach in 532 novice runners reported no reduction in injuries (20.8 versus 20.3% with standard training).³ Nevertheless, common sense would suggest that gradual increases in training volume are less likely to cause injury than sudden increases. Footwear is also an area of debate when it comes to lower limb injuries and the role it may play in reducing the risk of injury. 

Current opinions in Gaelic football would suggest that the use of blade-moulded boots rather than traditional stud boots are a contributing factor to the occurrence of cruciate ligament injuries. Based on limited evidence and clinical experience, we suggest using footwear that feels most comfortable and is well suited to the shape of the sports person’s foot. 

Role of nutrition

The role of nutrition is now coming into focus among sports people and those working with sports people. Correct nutrition is being shown to reduce the risk of injury and also aid in recovery from injury. The timing of nutrient intake is important. Nutritional intake high in carbohydrate, moderate in protein, and low in fat and fibre is generally well tolerated prior to exercise, whereas intake high in fat and fibre may cause gastrointestinal cramping or other distress. 

During exercise that lasts more than one hour, the athlete needs fluids and small amounts of carbohydrate, such as that found in sports drinks. A runner, such as a marathon runner, should be encouraged to replenish glycogen stores by consuming carbohydrate, at between 1.0 and 1.5g/kg of body weight, within 30 minutes of exercise, and to continue ‘refueling’ every two hours for four-to-six hours. These goals can be met with relatively small amounts of food. We also suggest adding protein to post-training nutrition to aid muscle recovery; this is likely most beneficial to the runner who does not take in adequate carbohydrate following exercise.⁴

Despite interventions to reduce lower limb injuries in sports people we are still being faced with the injuries outlined above. Therefore physicians need to be aware of some of the common lower limb injuries they are likely to face from sports with a running component.

Patellofemoral pain syndrome 

Patellofemoral pain syndrome (PFPS) is a very frequently encountered disorder that involves the patellofemoral region. It is the most common cause of knee pain seen by GPs, orthopedic surgeons and sports medicine consultants, and can be difficult to diagnose. PFPS affects many running athletes and constitutes nearly 25% of all identified knee injuries. It affects women more commonly, with a ratio of women to men of 2:1, and disproportionately in active adolescents and adults in the second and third decades of life. 

The aetiology is multifactorial, resulting from a complex interaction among intrinsic anatomic and extrinsic training factors. Although doctors frequently make the diagnosis, no clear consensus exists about its aetiology or the factors most responsible for causing pain. Overuse and trauma are most commonly documented as the causative factors. Overuse (ie. excessive training) is most common and this is in keeping with several studies which show that a runner’s total mileage correlates with the development of the syndrome. From a trauma perspective, direct and indirect injuries can damage structures around the patellofemoral joint. For example, direct blows sustained during falls or tackles in Gaelic football or other contact sports can injure the patella and trochlea, including articular surfaces and surrounding structures. Indirect injuries from falls or tackles in contact sports may include patellar dislocation/subluxations, retinacular strain or damage to the articular cartilage.

PFPS is a clinical diagnosis, with no pathognomonic sign or symptom. For most patients a careful history and physical examination establish the diagnosis, but the doctor must first exclude other conditions that mimic the syndrome. Typically knee pain from PFPS worsens with squatting, running, prolonged sitting or when ascending or descending steps. Pain is often poorly localised ‘under’ or ‘around’ the patella, and is usually described as ‘achey’. The doctor should rule out patellofemoral osteoarthritis, patellofemoral instability and similar conditions that cause anterior knee pain. Patellofemoral osteoarthritis occurs in patients who are older than those who develop PFPS and has characteristic radiographic findings. In PFPS instability you would expect a history of patellar dislocation or a sensation of instability or movement of the patella. Both of these disorders require specific treatments unrelated to PFPS.

The goals of treatment are to reduce pain and return the patient to as a high a level of function as possible. The acute phase of treatment during the first week focuses on pain control. Long-term the patient should receive physiotherapy to improve joint stability through appropriate exercises and possible adjustment of footwear. The degree of success in treatment is very variable. Surgical intervention is considered when non-operative therapies have failed, but is a treatment of last resort. Non-operative therapy should be pursued for six to 12 months prior to considering operative intervention. 

Medial tibial stress syndrome (shin splints) 

This syndrome is commonly known by patients as ‘shin splints’. It is a term people use to describe a pain they get in their tibia when exercising, and it is a common injury that affects athletes who engage in running and running-based sports. Medial tibial stress syndrome is caused by repeated trauma to the connective tissue surrounding the tibia. Unfortunately, it may result in a stress fracture if not managed correctly. The syndrome is most commonly experienced among those with poor arch structures or arch support for their feet. 

Medial tibial stress syndrome can usually be attributed to overloading the muscles of the lower extremities. If an athlete begins high levels/distances of running after not running for a long period of time, it puts stress on the muscles which they are unaccustomed to. The connective tissues around the tibia, ie. tendons and muscles, are unable to counteract the stresses experienced as they fatigue. Ultimately the unstrengthened structures are unable to perform to the stresses being imparted upon them. Associated pain occurs from a disruption of Shapey’s fibres that connect the medial soleus fascia through the periosteum of the tibia where it inserts into the bone. 

Diagnosis is based on a good clinical history with the exclusion of other pathologies. For an athlete the syndrome typically occurs late in a sports season for athletes or after prolonged activity for active individuals. Onset can also occur during the initial rigors of exercise after an individual has been inactive for a long period. Patients typically report the pain as a dull ache over the distal third of the tibia. Vascular and neurological pathologies should be excluded in the diagnosis of this syndrome. An important differential diagnosis is compartment syndrome. 

The treatment of the syndrome is multi-faceted and includes:

• Rest – for a runner, it should be advised to stop running or reduce the number of miles until the symptoms improve or go away 
• Elevation – elevate the leg when you are resting
• Ice – place a cold gel pack on the leg every one to two hours, for 15 minutes 
• Take analgesia – as required take an over-the-counter analgesic.

Stress fractures of metatarsals, tibia and fibula

Metatarsal, tibial and fibular stress fractures occur most commonly among athletes who participate in activities that involve prolonged walking, running or jumping. Although most common among runners, where the incidence may be as high as 15%, these injuries also occur among soccer players, GAA players and basketball players. They can also occur in non-athletes who suddenly increase their activity level or have an underlying illness predisposing them to stress fractures. 

There is a slightly increased ratio of women to men, and Caucasians have twice the risk of African-Americans. Possibly the most talked about metatarsal stress fracture in a sports person was when David Beckham sustained a stress fracture of his metatarsal prior to the 2002 World Cup. 

The aetiology of these fractures is not fully clear; however, possible risk factors are of three types:

• Activity-related factors, including excessive training, poor footwear, and irregular terrain
• Biomechanical factors, including inflexibility or weakness of the calf muscles, unequal leg-length, and flat or high-arched feet 
• Metabolic factors, including demineralised bone due to hormonal or nutritional imbalances and specific disease states.

The underlying features shared by this diverse group of proposed risk factors is their propensity either to increase the loading and bending forces placed on the bone or to reduce the capacity of the bone to handle such forces.

The tibia is the major weight-bearing bone of the lower limb. The proximal tibial plateau forms the lower surface of the knee joint. The tibial shaft bridges the distance to the distal tibia, which contributes the superior articular surface of the ankle joint at the tibiotalar articulation as well as the medial malleolus. Another key bony landmark is the tibial tuberosity, which sits several centimetres below the joint line and serves as the attachment site for the patellar tendon. Although the tibial shaft is the most common site for stress fractures, they may also occur at the tibial plateau and the medial malleolus. 

Initial symptoms in most athletes suggest medial tibial stress syndrome, commonly referred to as ‘shin splints’. Typically, there is a gradual progression of activity-related pain. Eventually the pain worsens and may occur with rest. Occasionally, the patient experiences an abrupt increase in pain at the site of milder chronic symptoms indicating that a repeatedly stressed area of bone has finally fractured. Diagnosis of a lower limb stress fracture is suggested by such a history in a patient with risk factors and the following clinical findings: pain localises to one specific area, local swelling and discrete bone tenderness are present, and pain increases with the impact from running or jumping.

Confirmation on initial plain x-rays occurs in less than 50% of stress fractures. Periosteal elevation, cortical thickening, sclerosis, or a true fracture line are positive findings. In patients who have an initially positive x-ray, follow-up radiographs are not necessary unless the patient fails to improve appropriately with treatment. In the majority of patients who do not have an initially positive x-ray, an experienced doctor may elect to treat presumptively as long as symptoms are in a low-risk area (eg. the medial posterior aspect of the tibial shaft). An exception is an athlete or other patient who will be embarking on a vigorous rehabilitation programme; in these cases, confirmation of the fracture is required by other means, such as magnetic resonance imaging (MRI). 

Initial treatment consists of rest and immobilisation. For fractures at greater risk for delayed healing or non-union, treatment can include a short period of non-weight-bearing and immobilisation in a splint. There is no standard follow-up schedule for stress fractures. Follow-up is adjusted according to the doctor’s judgement, patient symptoms and response to treatment. Patients with injuries at relatively high-risk sites are seen more frequently.

In recent times there is a question of an increased risk of osteoporosis among long-distance runners. This area is still under investigation but there may be a significant link between long-distance running, especially for women, and increased risk of osteoporosis and stress fractures. 

Achilles tendinopathy 

Problems relating to the Achilles tendon affect competitive and recreational athletes. It is the largest tendon in the body. It endures strain and risks rupture from running, jumping and sudden acceleration or deceleration. Overuse, vascular diseases, neuropathy and rheumatological diseases may cause tendon degeneration. The hallmarks of Achilles tendon problems seem to be damaged, weak, inelastic tissue. Achilles tendinopathy affects competitive and recreational athletes. The incidence of Achilles tendon rupture in the general population is seven per 100,000. Over 80% of ruptures occur during recreational sports. Approximately 10% of patients who sustain an Achilles tendon rupture had preexisting Achilles tendon problems. Observational data suggest that competitive athletes have a lifetime incidence of Achilles tendinopathy of 24%, with rupture in 8.3%. Among competitive runners, the lifetime incidence of Achilles tendinopathy may be as high as 40-50%. Competitive athletes with the highest risk of rupture include sprinters and soccer players, which is in keeping with the sudden acceleration and deceleration nature of their sports. 

Cold-weather training is associated with higher rates of tendon pain, while foot misalignment, poor running mechanics (excessive supination, inadequate dorsiflexion), inappropriate footwear, and leg length discrepancy are associated with tendon pain. Age, male gender and obesity are risk factors for Achilles tendon problems. The peak age for rupture is between 30 and 40 years for both men and women. Rupture is four-to-five times more common in men than women. Acute Achilles tendon pain generally develops when athletes abruptly increase their activity (eg. runners who start training for a marathon). Chronic tendon pain (> 3 months) may result from sustained stress, poor running mechanics (eg. supination, heel misalignment) or improper footwear.

Patients with Achilles tendinopathy typically complain of pain or stiffness 2-6cm above the posterior calcaneus. They are likely to be casual or competitive athletes who have increased their training regimen beyond their tendon’s ability to heal the microtrauma from repetitive stress, or who have been training rigorously for a long time. A history of excessive supination, increased speed work or hill training, or improper or worn-out footwear may be found. The pain is usually described as burning. Tendon rupture occurs when sudden forces are exerted upon the Achilles tendon during strenuous physical activities that involve sudden pivoting on a foot or rapid acceleration (eg. stop-and-go sports such as tennis). 

Many patients feel as if they were struck violently in the back of the ankle. In contrast to ankle sprains, where injury occurs with landing, symptom onset with tendon rupture generally occurs as the patient is pushing off with their foot.

The goal of treatment is to relieve symptoms and enable a return to activity. Treatment of acute Achilles tendinopathy generally consists of the following: avoid aggravating activities, apply ice when symptomatic, take a short course (7-10 days) of non-steroidal anti-inflammatory drugs (NSAIDs) and/or support the Achilles with a heel lift or bandage as needed. Initial management of Achilles tendon rupture consists of ice applied to the area, analgesics (paracetamol and/or NSAIDs are generally sufficient), rest (ie. non-weight-bearing with crutches), immobilisation with the ankle in some, plantar flexion (generally a splint is used), and referral to an orthopedic surgeon.

Plantar fasciitis 

Plantar fasciitis is a painful inflammatory process of the plantar fascia, the connective tissue on the undersurface of the foot. The predominant symptom of plantar fasciitis is pain in the plantar region of the foot that is worse when initiating walking. 

Plantar fasciitis is one of the most common causes of foot pain in adults, estimated to be responsible for about one million patient visits to the doctor per year in the US. The peak incidence occurs between ages 40 and 60 years in the general population, with a younger peak in runners and those partaking in running-based sports. It may be bilateral in up to one-third of cases. The aetiology is poorly understood and is probably multifactorial. Possible risk factors for the development of plantar fasciitis include obesity, prolonged standing or jumping and flat feet. There is a high incidence in runners, suggesting that plantar fasciitis, at least in this population, is due to an injury caused by repetitive microtrauma. 

The site of abnormality is typically near the origin of the plantar fascia at the medial tuberosity of the calcaneum. A hallmark for diagnosis of plantar fasciitis is local point tenderness. This is best elicited by the examiner dorsiflexing the patient’s toes with one hand, in order to pull the plantar fascia taut, and then palpating with the thumb or index finger of the other hand along the fascia from the heel to the forefoot. Points of discrete tenderness can be found and marked for possible later injection. 

Treatment steps of this condition is multifaceted:

• Performing stretching exercises for the plantar fascia and calf muscles
• Avoiding the use of flat shoes/barefoot walking
• Using prefabricated, over-the-counter, silicone heel shoe inserts 
• Decreasing physical activities that are suggested by the medical history to be causative or aggravating (eg. excessive running or jumping)
• Prescribing a short-term trial (two to three weeks) of NSAIDs
• Injecting the tender areas of the plantar region with glucocorticoids and a local anaesthetic. 

Other disorders to consider

The pathologies and disorders discussed here are by no means a complete list. Other disorders to consider include ankle sprain, Morton’s neuroma, chondromalacia patella, meniscal tears, tendinitis and ligament damage. Each of these requires a careful history and examination before instituting specific treatment and rehabilitation regimens.  

References 

1. van Gent RN, Siem D, van Middelkoop M et al. Incidence and determinants of lower extremity running injuries in long distance runners: a systematic review. Br J Sports Med 2007; 41(8): 469-80
2. Fields KB, Sykes JC, Walker KM, Jackson. Prevention of running injuries. Curr Sports Med Rep 2010; 9(3): 176
3. Buist I, Bredeweg SW, van Mechelen W et al. No effect of a graded training program on the number of running-related injuries in novice runners: a randomized controlled trial. Am J Sports Med 2008; 36(1): 33
4. Beelen M, Burke LM, Gibala MJ, van Loon L JC. Nutritional strategies to promote postexercise recovery. Int J Sport Nutr Exerc Metab 2010; 20(6): 515