Achilles Tendon Pain - Is it Tendonitis, Tendinosis or Tendinopathy?

What is Achilles Tendinopathy?

Achilles tendinopathy, also known as Achilles 'tendinitis' or 'tendinosis', is a common injury that can affect both athletes and non-athletes. The Achilles tendon, a thick spring-like structure of muscle-tendon, connects the calf muscles to the heel bone and plays a crucial role in propelling us forward when walking or running. When the Achilles tendon undergoes tendinopathic changes, which can occur at the mid-portion or insertion of the tendon, it can result in pain, swelling, and reduced strength and power. However, the classic sign of this condition is stiffness or pain in the morning.

Tendinopathy of the Achilles tendon is primarily caused by sudden or significant changes in loading, such as increased frequency, duration, or intensity of physical activity. This can include running more frequently, longer distances, incorporating more hills, increasing pace, or adding speed and accelerations to your routine. On the other hand, tendinopathy can also develop after a period of disuse or unloading, such as in the aftermath of illness, injury, or surgery, as the tendon's capacity and ability to tolerate load diminishes. Both scenarios can lead to the breakdown of the tendon's collagen structure and reduce its capacity to accept and produce force, resulting in pain and dysfunction.

How Does Achilles Tendinopathy Start?

The development and progression of Achilles tendinopathy can be attributed to the principles of loading and the pathogenesis of the condition. Understanding these factors can provide insight into how the condition begins and progresses, and guide treatment strategies for optimal recovery.

Loading Principles:

The Achilles tendon is a unique structure that responds to the loads placed upon it. It has the ability to adapt and become stronger when subjected to gradual increases in load. However, when the tendon is exposed to sudden or excessive loads, it can lead to breakdown and damage of the collagen fibers, resulting in tendinopathy. There are two main loading principles that contribute to the pathogenesis of Achilles tendinopathy:

1. Overload: Overloading occurs when the tendon is subjected to load beyond its capacity to adapt. This can happen due to sudden increases in physical activity levels, such as a significant increase in training volume, intensity, or frequency. For example, suddenly doubling the distance or intensity of your running sessions can overload the Achilles tendon and increase the risk of developing tendinopathy.

2. Underload: Underloading refers to the significant reduction or absence of load applied to the tendon. This can happen due to periods of rest, immobilization, or reduced physical activity levels, which may result from illness, injury, surgery, or lifestyle changes. Prolonged periods of underloading can lead to weakening and structural changes in the tendon, making it less tolerant to reintroduction of load and increasing the risk of tendinopathy.

Pathogenesis:

The pathogenesis or development of Achilles tendinopathy involves a complex interplay between mechanical and cellular responses. Here's a breakdown of the pathogenesis process:

1. Tendon Microtrauma: When the Achilles tendon is subjected to excessive or repetitive loads, it undergoes microtrauma. This causes tiny tears and damage to the collagen fibers within the tendon.

2. Inflammation and Cellular Response: The microtrauma triggers an inflammatory response within the tendon. Inflammatory cells, such as macrophages, are recruited to the site of injury, releasing inflammatory mediators that contribute to pain and tissue remodeling.

3. Collagen Degeneration and Disorganization: The excessive loading and ongoing inflammation result in the breakdown of collagen fibers and the accumulation of abnormal matrix components within the tendon. This leads to structural changes, such as collagen degeneration and disorganization.

4. Neovascularization: In response to the injury and ongoing healing process, the body attempts to supply oxygen and nutrients to the damaged area by forming new blood vessels (neovascularization). However, this process can also contribute to pain and pathology.

5. Nerve Sensitization: The inflammatory and structural changes within the tendon can sensitize the nerves surrounding the tendon, leading to heightened pain perception and altered pain signaling.

The combination of mechanical overload, underloading, tissue microtrauma, inflammation, collagen degeneration, neovascularization, and nerve sensitization sets the stage for the development and progression of Achilles tendinopathy. It is important to note that these processes can vary from person to person and may be influenced by factors such as genetics, age, activity level, and overall health.

Understanding the loading principles and pathogenesis of Achilles tendinopathy allows healthcare professionals, such as physiotherapists, to develop targeted treatment plans. By addressing the underlying factors that contribute to tendinopathy, these treatment strategies can focus on optimizing loading patterns, promoting tissue healing, managing inflammation, and improving biomechanics. Working closely with a knowledgeable physiotherapist can help individuals with Achilles tendinopathy navigate these aspects effectively to support their recovery journey.

How to Fix Achilles Tendinopathy

Now that we understand what Achilles tendinopathy is and how it is caused, let's explore the different treatment options available. It can be overwhelming to choose the most effective treatment amidst the numerous choices out there, but research has shown that eccentric or heavy-slow resistance exercise programs are highly effective for Achilles tendinopathy. Eccentric exercises involve lengthening the muscle-tendon unit while under load and have been proven to increase collagen synthesis and improve tendon strength and function. Heavy-slow resistance training programs focus on high load strength work through both concentric (shortening) and eccentric work for the achilles. To ensure proper form and progression of these exercises, it is essential to seek guidance from a qualified physiotherapist.

Heavy Slow Resistance Training For Achilles Tendinopathy:

Heavy slow resistance training (HSR) is another treatment option that has shown promising results in Achilles tendinopathy management. This approach involves performing eccentric exercises with heavy loads and slow movement speeds in a controlled manner. A study by Beyer & Kongsgaard et al. (2015), published in the American Journal of Sports Medicine, investigated the effects of HSR vs classic eccentric only exercise on clinical outcomes, Achilles tendon structure and function in patients with tendinopathy. The study found that HSR resulted in significant improvements in tendon mechanical properties and patient-reported outcomes equal to or better than eccentric exercise, with high patient satisfaction at 12 weeks.

Implementing a HSR program should be done under the supervision of a qualified physiotherapist or strength and conditioning specialist. HSR programs typically involve performing progressive, heavy loaded exercises such as leg press, squats, and calf raises, progressing to power and plyometric exercises like a sled push, skipping or box Jumps to target the tendons stiffness, stretch-shortening cycle, work capacity and the whole kinetic chain. The load and progression of the exercises should be carefully managed to ensure they are within the patient's pain tolerance and capacity for adaptation.

Running Mechanics and Run Re-training for Achilles Tendon Pain:

Running mechanics and footwear may also play an important role in the management of Achilles tendinopathy. Understanding and improving your running form, as well as selecting appropriate footwear, can help decrease stress on the Achilles tendon and facilitate recovery.

Running with proper form can reduce excessive strain on the Achilles tendon and minimize the risk of developing or worsening tendinopathy. Some key aspects of good running mechanics include:

1. Posture: Maintain an upright posture while running, avoiding excessive leaning forward or backward. This helps distribute forces evenly throughout the body.

2. Foot Strike: Aim for a midfoot rather than a heel strike. Landing on the midfoot allows for better shock absorption and reduces the loading on the Achilles tendon. forefoot striking can place increased loads on the achilles tendon, which is fince if you have the capactiy to tolerate that too.

3. Cadence: Strive for a higher cadence (steps per minute). Increasing your cadence can help reduce the impact forces on the Achilles tendon.

4. Stride Length:

Avoid overstriding, which means landing with your foot too far in front of your body. This can increase stress on the Achilles tendon. Instead, aim for a slightly shorter stride length with a faster turnover.

5. Lower Limb Strength and Stability: Strengthening the muscles of the lower limb, including the calves and glutes, can improve running mechanics and reduce strain on the Achilles tendon.

Footwear Can Help Achilles Pain?

Choosing the right running shoes is crucial in preventing and managing Achilles tendinopathy. Here are some considerations when selecting footwear:

1. Cushioning: Look for shoes with adequate heel cushioning to absorb shock and reduce the impact on the foot and Achilles tendon.

2. Heel-to-Toe Drop (Pitch): The heel-to-toe drop refers to the difference in height between the heel and the forefoot of the shoe, known as the pitch. For individuals with symptomatic Achilles tendinopathy, shoes with a higher heel-to-toe drop may be beneficial, as they promote less excursion through range for the achilles and reduce stress on the tendon.

3. Arch Support: Choose shoes with appropriate arch support that match your foot structure. Some individuals may benefit from arch support to help distribute forces evenly throughout the foot and reduce tension on the Achilles tendon. If you have a flat foot or significant dynamic pronation then this might be contributing to your achilles tendon pain.

4.Proper Fit and Shoe Health: Ensure that your shoes fit well and provide enough room for your toes to move freely. Ill-fitting shoes can cause biomechanical imbalances and contribute to tendon overloading. Also, if your shoes have done greater than 500km walking or 300km running, most manufacturers say they have lost their support and a new shoe might be in order!

Integrating proper running mechanics, choosing appropriate footwear, and considering HSR as part of an individualized treatment plan can contribute to the successful management of Achilles tendinopathy. Consulting with a physiotherapist who specializes in tendon injuries can help tailor these interventions to your specific needs and facilitate an optimal recovery.

Other Treatment Options for Achilles Tendinopathy:

In addition to the afore mentioned exercise programs, footwear and running re-training, there are other treatment options that can complement the exercise program and provide pain relief. These options include:

1. Isometrics for Achilles Pain:

Isometric exercises, which involve muscle contractions without movement, can strengthen the calf muscles without placing excessive strain on the tendon. These are not a panacea to your tendinopathy unfortunatley, but can help manage the more painful periods and get you started on a progressive loading program. Make sure you progress from these into a HSR exercise program though and don’t just perform isometric holds forever!

2. Massage: Deep tissue massage performed by a qualified therapist can help relieve muscle tension and promote blood flow to the tendon, aiding in the healing process, improving mobility and calf length.

3. Dry needling: There is some support for the effectiveness of dry needling on pain in the literature, a technique that involves the insertion of thin needles into trigger points in the calf muscles. This treatment can reduce tension and promote healing, leading to pain reduction and improved function.

4. Taping: Taping techniques can provide support and stability to the Achilles tendon, reducing pain and improving function. Your physiotherapist can demonstrate the proper application of taping for maximum benefit.

5. Heel inserts and Footwear: Orthotics or heel inserts can cushion and support the heel, reducing stress on the Achilles tendon, especially for individuals with flat feet or high arches. Looking at your shoes can also be super helpful in the long run.

6. Shockwave therapy: Research published suggests that shockwave therapy, which involves the delivery of high-energy sound waves to stimulate tendon healing, can reduce pain and improve function in patients with Achilles tendinopathy. Unfortunately, this is less than guaranteed and without the addition of a well structred loading programme is likely to achieve little more than pain relief in the short term.

Things to Avoid For Achilles Pain

While we are on the topic of treatment options, here are some things to avoid (and avoid the person offering them as they are likley not up to date on their knowledge of current best practices for achilles tendon pain and rehabilitation!):

1. Complete Rest: Rarely is full unloading of the tendon a good idea! Tendons like the achilles love load, they are locomotion springs! Unloading them fully can have detrimental effects that can be hard to get back from if done for too long. Instead, relative rest is the best option. What this means is finding the level of tolerance for laoding capacity in your tendon and working at that level to maintain the integrity of your tendon while we build it back up. That could mean strength training in the gym is still OK, but plyometric and power sessions are modified or ommited for now.

2. Ultrasound Therapy: This is old school and has zero evidence for success in treating achilles heel pain. Avoid it.

3. Stretching: If your physiotherapist prescirbes stretches and no strength work, they are doing you a disservice. Stetching can feel nice and seem helpful but it wont change the working capacity of your tendon and its ability to produce and absorb force, and so ultimately wont help. Worse, if you have insertional achilles tendinopathy it can actually make things more painful!

Conclusion:

Achilles Tendon Pain can be hard to manage, and frustrating, for both the patient and physio at times. To optimize your recovery and ensure the most effective treatment, it is essential to work closely with your physiotherapist, who can guide you through individualized exercises, monitor your progress, and make necessary adjustments along the way. Achilles tendinopathy can be a challenging condition, but with the right approach and dedication, you can overcome it and return to pain-free movement and activity. Gravity Physio Brookvale on the Northern Beaches can help those suffering with this condition, so visit our online bookings page and start your recovery now.