Unraveling the Metabolic Basis for Tendon Pain

Tendon pain, particularly chronic Achilles tendinopathy, is a challenging condition that can disrupt an active lifestyle especially for runners.

In recent years, researchers have delved into the metabolic underpinnings of tendon pain, shedding light on the role of lactate concentrations.

The Lactate Connection

Lactate, a compound associated with muscle fatigue and soreness, has emerged as a crucial factor in the study of painful chronic Achilles tendinopathy.

A study utilizing microdialysis techniques revealed higher concentrations of lactate in Achilles tendons afflicted by tendinopathy compared to healthy, pain-free tendons.

The significance of this finding lies in the revelation of anaerobic conditions within the painful tendon area.

Understanding the Results

The study's results are a piece of the intricate puzzle of tendon pain.

Let's break down what we can glean from this research:

1. Lactate Accumulation: The higher concentrations of lactate in painful tendons suggest that anaerobic conditions prevail in the affected area. This accumulation of lactate reflects a metabolic imbalance within the tendon, which may contribute to pain perception.

2. Tendon Structure: The study noted structural changes and widening of the tendon in cases of tendinosis. These observations are vital in understanding the pathological processes at play in chronic Achilles tendon.

A Holistic Approach to Tendon Pain Management

Understanding the metabolic basis of tendon pain is just the first step.

To effectively manage and alleviate this pain, we must take a holistic approach:

1. Training Load and Periodization: In the world of sports and physical activity, it's essential to adopt a balanced training load. The 80/20 principle, where 80% of training is in zone 2 (aerobic), can help minimize the risk of overuse injuries like tendinopathy.

2. Lactate Clearance: Optimal lactate clearance is key. Encourage activities that enhance lactate clearance, such as low-intensity exercise, adequate recovery periods, and proper hydration.

3. Therapeutic Modalities: Various therapeutic modalities can play a role in tendon pain management. These include massage, dry needling, and foam rolling, which can aid in reducing muscle tension and promoting blood flow to the affected area.

4. Liver and Kidney Health: Metabolic health is crucial. Liver and kidney health is vital for efficient metabolite clearance, including lactate. Ensure a balanced diet, stay hydrated, and minimize excessive alcohol consumption to maintain these organs' well-being.

5. Hydration: Proper hydration is essential to support overall metabolic processes, including lactate clearance. Staying adequately hydrated aids in reducing the risk of metabolic imbalances contributing to tendon pain.

Conclusion

The metabolic basis for tendon pain, as revealed in the study, offers valuable insights into the pathogenesis of chronic Achilles tendinopathy.

However, it's only one piece of the puzzle. To effectively manage tendon pain, we must adopt a holistic approach.

This approach includes optimizing training load, prioritizing lactate clearance, and utilizing therapeutic modalities to promote pain relief.

Furthermore, maintaining overall metabolic health through hydration and balanced nutrition is paramount.

As we continue to unravel the intricate nature of tendon pain, adopting a holistic approach can help individuals regain their active lifestyles and harmonize with their bodies' natural healing mechanisms.

Research link: High intratendinous lactate levels in painful chronic Achilles tendinosis. An investigation using microdialysis technique

Soleus Trigger Points: The Achilles' Heel of Running Pain

"Where you think it is, it ain't."

As the great massage therapist Ida Rolf once said, "Where you think it is, it ain't."

This profound statement holds a lot of truth, especially when it comes to understanding and managing pain in the world of running.

Many runners have experienced Achilles tendon pain, and often, the source of this discomfort can be quite elusive.

Surprisingly, it may not always originate from the Achilles tendon itself.

In this blog post, we'll explore the concept of soleus trigger points and how they can refer pain to the Achilles.

We'll also discuss strategies to manage and prevent this type of discomfort.

The Soleus: A Hidden Culprit

The red area around the achilles and heel is known as ‘referred pain’ from the soleus muscle

The soleus muscle is a powerful calf muscle that plays a crucial role in running.

It is often overshadowed by its more prominent counterpart, the gastrocnemius, but the soleus is no less important.

When it comes to running, the soleus carries a substantial load, approximately 6-8 times your body weight with every step. Over weeks and months, this load can accumulate and cause various issues, one of which is trigger points.

Trigger points are hyperirritable knots or tight bands within a muscle that can cause pain locally or refer pain to other areas. They commonly are a result of excess waste products/metabolites (such as lactate) build up in the muscle when the muscle has worked harder than usual.

In the case of the soleus, these trigger points can lead to discomfort that radiates to the Achilles tendon, even when the tendon itself is healthy.

The New Runner's Dilemma

New runners are particularly susceptible to developing soleus trigger points.

The tightness in the soleus may have been building up gradually, and with a lack of experience, they may inadvertently make mistakes in managing their running-related discomfort.

Often, new runners tend to focus on stretching, but this can be counterproductive, especially when stretching with a straight knee, which primarily targets the more superficial muscle known as the gastrocnemius.

Understanding the Pain Pathway

The referral of pain from the soleus to the Achilles tendon occurs due to the shared neural pathways and the close proximity of these structures.

It's crucial to recognize that the Achilles pain can be a result of metabolic waste buildup in the soleus, not a direct issue with the tendon itself.

This insight can be transformative in managing and preventing such pain.

An assessment with an experienced running Physiotherapist who uses a load management approach (rather than a short sighted purely biomedical approach) early on can save you a lot of time and hassle down the track.

Albert Einstein is quoted as having said, “If I had an hour to solve a problem I'd spend 55 minutes thinking about the problem and five minutes thinking about solutions.” The point he makes is important: really listening and deeply understanding the context of the problem has great value in effectively solving the problem.

Tips for Managing Soleus Trigger Points and Achilles Pain

1. Dry Needling: Dry needling by a trained healthcare professional can be effective in releasing trigger points in the soleus muscle, reducing pain, and restoring normal muscle function.

2. Load Management Advice: Avoid overloading the calf muscles, especially if you're new to running. Implement the 80/20 rule, where 80% of your training is at a comfortable pace (Zone 2) to build your mitochondrial capacity while limiting high-intensity workouts.

3. Foam Rolling: Use a foam roller to massage your calf muscles after your runs. This can help release tension and prevent the buildup of trigger points.

4. Shoe Maintenance: Ensure your running shoes are well-maintained and provide the necessary support. Proper footwear can reduce excessive stress on your calf muscles and Achilles tendon.

5. Running Technique: Pay attention to your running form. Avoid overstriding with a heel strike, as this places a significant load on the Achilles. Aim for a midfoot strike (as opposed to forefoot strike) with a cadence of 170-180 steps per minute. When walking, avoid heel striking and aim for a cadence of 120-130 steps per minute.

6. Avoid Compression Loads: Be cautious about using hard massage tools, rolling balls, or aggressive stretching on your calf muscles and Achilles. Overdoing it can lead to further irritation, which would only present 24 hours later. Don’t win the battle but lose the war.

Conclusion

The Achilles' heel of running pain often resides in the soleus muscle, with trigger points causing discomfort that radiates to the Achilles tendon.

Understanding this relationship is crucial for effective management and prevention.

By incorporating the tips mentioned above, you can help alleviate pain, improve your running experience, and keep your Achilles tendon healthy.

Remember, sometimes where you think the pain is, it ain't – it might just be the soleus!

Tendinopathy Update

The past weekend I attended Peter Malliaras's course, 'Mastering Lower Limb Tendinopathies'.

Peter is an Associate Professor at Monash University and has spent many years researching and working with people with tendon problems. 

In recent years there has been a lot of significant new research in the world of tendon rehab.

If you've ever had an issue with an ongoing tendon problem, you can understand how frustrating the long term pain and dysfunction can be. 

There is much conflicting advice and out dated treatment approaches that can contribute to the poor outcomes many people face with tendon injuries. 

Thankfully, Peter has put all of the latest based evidence into a comprehensible format and in this blog post I'd like to share just a little summary.

This blog would be particularly helpful if you suffer from ongoing pain in the:

• Achilles tendon

• Hamstring

• Patella tendon

• Hip pain/bursitis

• Plantar fascia

What is a tendon?

Tendons connect the muscle to bone.  They are made up primarily of collagen fibres.

In the lower limb, role of tendon is to absorb and release energy

Tendons are like springs that absorb stretching forces and then release energy when we move.

What causes tendon problems?

Tendons are very sensitive to changes in load. 

Essentially, tendons become injured when we over-load them too soon, or when demand exceeds capacity.

This can be from:

• too much volume

• too much intensity

• change in footwear or surface

For example a runner may start to include sprinting or hill work too soon or increase mileage suddenly leading up to a big race.

High training load is not a risk for injuries, it's how you get there that is the important factor (i.e. avoiding acute spikes in training loads).

                   Tendons become damaged when demand exceeds their capacity

What is the difference between Tendinitis and Tendinopathy?

Tendinitis refers to the inflammation in the early stages of an injury. 

This is opposed to tendinopathy that refers to the process of degeneration that tendon goes through in response to chronic overload.

Recent research suggests a lot of what we previously thought of as tendon inflammation was actually related to tendinopathy.

Who is likely to suffer from a tendon problem?

Patella tendon (front of knee)

Usually occurs in younger people involved in jumping sports such as volleyball, basketball and football.  There is some evidence to suggest pathological tendon changes can begin in early adolescence if there excess load on the maturing collagen in the tendon.

Achilles tendon (back of heel)

Affects people across the lifespan, in particular long distance runners, sprinters, football and soccer players.  Often there is pain and stiffness that is worse on waking and when running. 

Gluteal tendon (side of hip)

Common in young females that are doing a lot of running or playing sport.  Also older women, especially around menopause or after post a hip injury / surgery.  Pain is often worse at night time, standing and walking.  There is some research showing a reduction in oestrogen can pre-dispose to tendinopathy. 

Hamstring tendon (back of hip)

Fast walkers, footballers, runners and people who do a lot of yoga are susceptible to hamstring tendinopathy.  They often experience pain on sitting, walking and bending forwards. 

What are the key risk factors for developing tendinopathy?

One of the biggest risk factors for a tendon injury is a past injury (2-19x greater risk of injury).

According to the research, people with tendon problems are not getting the rehabilitation and re-building of capacity they need.

Often patients self-discharge when their pain has gone away. 

It is imperative for the treating clinician to educate the patient that rehabilitation is a two step process:

1.  Reducing pain and then

2.  Re-building capacity in the tissues to match the demands placed on them

Other systemic conditions that can increase the risk of developing tendon pain include:

• Type 2 Diabetes ( 3 x risk)

• High cholesterol

• High blood pressure

• Menopause

• Obesity

• Inflammatory arthropathies

Some other factors that put you at a higher risk of ongoing tendon pain:

• unrealistic beliefs about likely healing time and optimal load management strategies

• inaccurate beliefs pain e.g. avoiding movement due to fear or rupturing a tendon

• too much passive treatment

• reduced variability of movement / exercise

How is a diagnosis made? 

Tendon issues are diagnosed with a combination of history and physical testing. 

If you have a localised pain that gets worse with movement and you can recall a sudden change in loading, there is a good chance you have a tendon problem.

Do I need a scan? 

Ultrasound scans can be useful to confirm the diagnosis and rule out certain other conditions. 

(See below for more info on scans)

Recovery and Management :

1.  Education ... (And Addressing Beliefs About Pain)

The long term goal is to create greater capacity in the tissues and this is your job, under the guidance of the physiotherapist looking after you.  

Manual therapy and dry needling does have a role to play in the short term to decrease pain and normalise muscle tone.

Credit: Jill Cook

Pain and Pathology

You may have a scary sounding ultrasound report, with words such as 'severely degenerative'.

The bad news first.  Your scans will most probably always look terrible. 

Structurally over time, there will be no change, despite what you do in terms of treatment.

The good news:

Many high quality research studies have shown that there is no correlation between pain and structural changes on scans. 

Your tendon will always be degenerated.

However, the thing we do have control over is the mechanical adaptation in the tissues around the tendon, as well as optimising biomechanics and sharing the load around the body.

The goal of treatment is to build the capacity in the tissues surrounding the tendon so that it meets the demand and creates a buffer zone of relaxation.

Some very important things to remember:

"Pathology is common in people without pain, so it cannot be the cause of pain.

Worse pathology does not mean it will be harder for you to get better.

Tendon pathology often does not change, even when the pain resolves" - Peter Malliaras
 

Recovery Time Line

It's important to understand the nature of recovery is often a case of 2 steps forward and 1 step back pattern. 

It's normal for your pain levels to fluctuate.

If you can accept this, while continuing with your rehab, you will have a much greater chance of success.

Credit: Adam Meakins

2.  Reduce the load temporarily while reducing pain and inflammation

Pain can be brought under control by managing load and using ice and NSAID's. 

You may need to take a short break from any aggravating activities.

If you can't take anti-inflammatories you may need to look at your diet for areas to address inflammation.

How can isometrics help decrease pain?

Isometric refers to a static contraction of a muscle without any movement. 

For example the diagram below shows an isometric contraction of the calf/achilles:

Benefits of isometric contractions in tendon healing (Malliaras et al 2013):

• Isometrics can decrease pain without adding excess load to the tendon.  

• time under tension can be maximized to allow greater tendon strain, which is a likely stimulus for tendon adaptation

• there is minimal soreness after doing isometrics, making them an ideal exercise 'during season'

• loading can be performed in a range that is not painful and tendon compression can be minimized

The positive research around isometrics is in it's early stages and mainly focuses around the patella tendon.

3. Assess current load capacity and tolerance then begin re-loading the tendon.

Your Physiotherapist will take you through a comprehensive load capacity assessment and then develop a re-loading strategy.

This most important factor is that we progress the load over time to bring out positive adaptation and improved load tolerance. 

You will most likely meet with your Physio once per week in the short term to closely monitor and progress the load at a suitable rate.

4.  Clean up biomechanical issues and kinetic chain deficits

Biomechanical issues that may need addressing:

• poor running technique

• over-pronation

• landing mechanics

• postural issues

Kinetic chain deficits that may need addressing:

• weak glutes

• weak calves

• weak quads

• weak hamstrings, adductors

• weak core

• excessively tight muscles and joint restrictions

We will address these factors in the clinic.  By optimising your movement efficiency, you will increase the likelihood of successfully returning to doing what you love and staying pain-free.

5.  Progress the load and build capacity to greater than demand and gradually ease back into sport / exercise

This is where you get to really to push the boundaries of building capacity and gradually resume training and getting back to what you love. 

It's important at this stage to think not only about training but also proper recovery to allow the tissues to optimally adapt. 

You will want to optimise things like sleep, food / protein intake and foam rolling to keep your muscles tuned up.

This stage may weeks / months to fine tune and this is where we will monitor you loads to ensure a successful return.

In Summary - 5 Take Home Messages:

1.  There Is Hope

Despite your ugly looking scan and long-term pain, there is good evidence to suggest you can make a good recovery and get back to doing what you enjoy.

2.  It Takes Time

Tendons are resilient and adapt.  But you need to give them time. 

The time-frame on average to achieve this is a minimum of 12 weeks (but continual small improvements can still occur up to 5 years later).

3.  Get Assessed By A Physiotherapist

There is a significant degree of complexity involved in a tendon problem and a Physiotherapist, after a comprehensive assessment will be able to guide you towards a positive outcome. 

4.  Only Exercise Can Increase Load Tolerance

"Your tissue capacity will only be as good as the load you put on it" - Professor Jill Cook

The end game is to build your resilience and capacity to create a 'buffer' zone of relaxation. 

5.  Think Quality Of Movement Before Quantity

Movement capacity develops step by step. 

Small mindful movement of the muscle-tendon complex can improve efficiency and help ensure that your tendon issue becomes a thing of the past.

This is where Pilates can be very useful. 

Pilates provides the perfect environment for sharpening the mind-muscle connection and also introduces elements of movement variability that help improve resilience.

Bonus Tips:

• PRP injections are a waste of time

• Steroid injections can have short term benefit but 12 months later can end up worse due to weakening of the tendon.

• Fast walking can cause hamstring issues

• For a tendon problem, generally it's best to avoid stretching

• Hip bursitis is treated with same strategies as gluteal tendinopathy

• Extracorporal Shockwave therapy is worth trying (more info about this click visit our friends at Adelaide Podiatry)

Thanks for reading this summary and if you have any questions or comments, please feel free to email dan@kinfolkwellness.com.au

If you have a tendon issue you would like to have assessed, I'd be honoured to help guide you.  

You can make a booking using our easy online system here.