RUNNING RELATED INJURIES

Below is a list of common injuries that runners using prostheses are most susceptible to. this is not a complete list of all possible running injuries. If you believe that you may be suffering from one of these injuries or any others as a result of your running it is important that you seek out a clinician, such as a physical therapist, to help you with the rehabilitation process. 

Common Injuries for All Levels of Amputation: 

Injuries to the Residual Limb:

• Skin abrasions 
• Pressure sores 
• Blisters 
• Rashes 

Caused By:

• Improper fit of the prosthesis
  • If you experience a decrease in volume of your residual limb the socket may not fit properly anymore. This can cause pistoning of your residual limb in the socket which results in increased shear forces, or rubbing, of the skin causing an increased susceptibility for skin breakdown. 
  • If you suspect any of the above are happening, talk with your prosthetist to see if an adjustment may need to be made to your prosthesis
• Inadequate rest for the residual limb

Osteoarthritis

• Osteoarthritis, or degenerative changes in the bone, is a common occurrence in the knees of runners using prostheses, regardless of whether you have unilateral or bilateral amputations. 
  • If you only have an amputation on one side, your unaffected limb is the most susceptible to developing osteoarthritis. This is because the unaffected side is often overloaded due to a lack of trust in the prosthetic limb or a decreased desire to spend as much time on the prosthesis. 
    • The risk for this increases if your amputation is above the knee as opposed to below the knee due to the fact that asymmetry in gait increases with a higher level of amputation. 
  • For individuals with below knee bilateral amputations both knees are equally susceptible to these degenerative changes. 
• The key point regarding osteoarthritis is that these changes in the joint develop over time as a result of altered loading of your legs. With proper strengthening and proper running form, you can help reduce the abnormal forces in your legs and decrease your chances of developing osteoarthritis. 
• Common signs and symptoms of osteoarthritis in the knee include pain, stiffness in the morning or with sitting for prolonged periods, decreased motion in the knee, warmth and swelling, and crackly sounds with movement of the knee. 

MUSCLE STRAINS ON THE PROSTHETIC SIDE

For an individual without an amputation who is running, the primary power generator is the plantarflexors, or the calf musculature. Without these muscles, as in the case of an individual with a lower limb amputation, the hip and knee musculature are required to work overtime in order to compensate for this loss and propel the runner forward. 

HAMSTRING STRAINS (WITH BELOW KNEE AMPUTATIONS)

• A hamstring strain is a tear in the hamstring muscle
• Contributing Factors
  • One contributing factor for hamstring strains is that often the prosthesis limits full motion at the knee and can prevent one from fully straightening the knee. This is turn causes shortness, or muscle tightness, of the hamstrings and the hip flexors. 
  • In addition to the hamstrings shortening, they are also under a greater demand to power the runner forward on the prosthetic side due to the decreased calf musculature. These two factors combine cause the hamstring to become overworked and result in a muscle strain. 
• Signs and Symptoms: Pain in the back of the thigh especially when using the muscle (when you actively bend your knee), tenderness to touch, tenderness while performing a hamstring stretch, possibly bruising, and some may report a pop or tear when they feel the strain occur. 
• In order to minimize the risk for a hamstring strain it is important to stretch and strengthen the hamstrings as well as the hip musculature so that they can share the work that is required for running.

LOWER BACK PAIN

• Back pain is incredibly common in the general population and the risk for low back pain is even greater for individuals with lower limb amputations. Kulkarni et al. found that 63% of subjects with amputations experienced moderate to severe back pain, 38% of which stated the pain interfered significantly with their lifestyle. 
• Contributing Factors 
  • Socket fit and prosthetic alignment
  • Shortened (or tight) hip flexors causing the pelvis to tip anteriorly, or forward, which increases the curvature of the low back thereby increasing the stress on the vertebrae and resulting in pain. 
  • General deconditioning of the back musculature. 
• In order to prevent back pain it is important to ensure you have a prosthesis that fits properly, that you regularly stretch, and that you perform core strengthening exercises. 

Common Injuries for those with Unilateral Amputations

overuse injuries

The biggest complication for those with a unilateral amputation is that people tend to spend more time on the unaffected leg and decrease the amount of time they spend on their prosthesis. This can be due to any number of reasons including a lack of trust in the prosthesis, pain in the residual limb or fear of injuring the residual limb. Often individuals don't even realize that they are spending less time on their prosthesis compared to their unaffected leg. The problem is that when you spend more time on one leg, it is subjected to a greater amount of force than it should be and overuse injuries on the unaffected side tend to occur. These include: 

• Plantar Fasciitis 
  • Pain and inflammation of the plantar fascia which is a thick band of tissue that runs along the bottom of your foot. 
  • Signs and Symptoms: usually a stabbing pain near the heel, often the worst in the first few steps after waking up or after long periods of being up on your feet. 
• Achilles Tendinosis 
  • Achilles tendinosis is caused by microtears in the tendon which lead to inflammation, pain and reduced motion.
  • Signs and Symptoms: Gradual onset of heel pain and swelling in the tendon which will be exacerbated with activity. Some individuals may notice a bump in the tendon. 
• Stress Fractures 
  • Stress fractures are tiny cracks in bone that are the result of cumulative excess force and overloading over a period of time. Initially, a stress reaction will occur and if proper rest is afforded, a stress fracture can be avoided and recovery time will be less. However, if one attempts to run through a stress reaction, a stress fracture will develop.   
  • Signs and Symptoms: Common locations for stress fractures in runners include the foot and shin. Symptoms will include pain and tenderness with palpation of the bone. Pain will increase with activity and eventually will be present even with walking.  

In order to minimize your risk for these injuries it is critical to take proper care of your residual limb, ensure trust in your prosthesis, strengthen your legs, and run with proper form. 

Common Injuries for those with Bilateral Amputations

Balance difficulties resulting in falls

 For individuals with bilateral amputations, maintaining balance during tasks such as running, is much more challenging than for individuals with an amputation on only one side. One study has shown that for all runners, increased running speed results in increased variability in foot placement, but the variability is greater in individuals with bilateral amputations compared to individuals with one or without any lower limb amputations. As a result of this increased variability, the ability to maintain balance becomes increasingly challenging with increasing speeds. 

One contributor to this difficulty in maintaining balance is a lack of proprioception, or joint position sense, and sensation due to the fact that the ankle and maybe knee are no longer present. Proprioception is the ability of your joints to detect where you are in space and correct for any factors that may challenge your balance so that you can maintain stability. Sensation also helps you to detect where you are and what your body is doing in order to maintain balance. As a result of amputation, both sensation and proprioception are lacking and are not replaced by a prosthesis. Therefore you need to work on balance activities to train the residual limb to have a sense of where it is in space. Start with balance activities where you are standing in place and then move on to agility based activities where you will perform quick movements that require a greater demand on your balance capabilities. 

When you begin running, you may want to start indoors on a track or treadmill where the surface is level. Running outside where there are uneven surfaces may result in falls. Once you feel comfortable and you are more confident with your ability to maintain balance you can try running outdoors.