Welcome to Our 3-Part Tendon Series

Tendons are often overlooked until they start hurting. Whether you’re dealing with nagging shoulder pain, stubborn Achilles tightness, or knee discomfort from running or jumping, tendon issues can be frustrating and slow to heal. As physical therapists, we are frequently treating tendon issues.

That’s why we’ve created this 3-part blog series to help you better understand tendons, what they need to function efficiently, what is happening when they stop functioning efficiently, and lastly how they heal. Here’s what we’ll cover:

Part 1: How Healthy Tendons Work – We’ll break down what tendons are, what they do, and why they’re built the way they are.

Part 2: Understanding Tendinopathy: Why Tendons Become Painful – We’ll look at tendon pain, overuse, and the common patterns we see when tendons get irritated or injured.

Part 3: How Physical Therapy Can Help Tendons Heal – We’ll explore treatment strategies and what you can do (and avoid) to get back to doing what you love.

Let’s start with the basics. What tendons are and how they function when everything is working right.

What is a Tendon?

A tendon is a tough, rope-like tissue that connects your muscles to your bones. Opposed to ligaments which are passive structures that connect bone to bone. It’s like a tow cable where your muscles generate the force, and the tendon delivers it to the bone to make movement happen. Every step, lift, or stretch relies on healthy tendons working behind the scenes.

Tendons are more than just connectors

Tendons can be thought of as very dynamic rope. Tendons help to transfer force from muscles to bones and that’s what creates motion. Tendons also absorb and release energy, helping movements like jumping or running feel smooth and powerful. Additionally, they help to distribute stress and force evenly across joints. Another surprising thing tendons do is provide body awareness by helping your brain sense tension and position, this term is called proprioception.

Some tendons are built to store energy, for example the Achilles acts like a spring with walking, running and jumping. Others are more about precision and control like the tendons in your fingers or shoulder.

What are tendons made of?

Lets zoom in closer and under the skin on tendons. They are mostly made of collagen fibers, bundled like a strong braided rope. These fibers are stretchy but strong, and give the tendon its structure and power. Inside the tendon are specialized cells called tenocytes, they monitor stress, repair tissue, and help the tendon adapt over time. These are incredible and dynamic cells, their job is to respond to stimulus that is put on a tendon, make collagen in response to this stimulus and keep the tendon healthy and strong over time.

Tendons also contain small blood vessels, nerves, and support cells, but they don’t have as much blood supply as muscle or skin. 

How do tendons stay strong?

Tendons love to be used but just the right amount, not too much (think overuse) but not too little (think atrophy).

When we use tendons regularly and with the right load, they adapt by getting stronger and resilient to handle more force, thicken slightly (in a positive way!) to better absorb stress, and with load they increase collagen production to improve their structural integrity. 

But when tendons are overused without enough rest, or not used at all, they can weaken. That’s when pain and injury often show up.

Tendons have less blood supply

Tendon’s don’t heal as fast as skin or muscle. That’s partly because they have less blood flow, the respond slower to stress compared to other tissues in the body, and they rely on movement to heal – but not too much or too soon.

This is why “just resting” alone rarely solves the problem, and also why doing specific movement and strengthening at the appropriate time is so important (we’ll get into that more in Part 3).

How can you tell if your tendons are working well?

We can’t always “see” tendon health on the surface. But there are functional ways to assess it. Indications that a particular tendon might be upset could include pain or weakness with specific tasks like jumping and lifting or if one side is tighter or weaker compared to another. These can all be clues that a tendon might not be functioning at 100%.

Final Thoughts: the big picture on tendons

Tendons play a quiet but powerful role in helping us move, perform, and stay active. When healthy, they’re strong, springy, and responsive. When stressed, they can become painful and stubborn to fix, however, they can adapt and improve with the right approach.

In part 2 of our tendon series, we’ll dive into what happens when tendons start to break down or get overloaded, why pain develops, and what’s really going on inside the tissue.

Have a question about tendon health or an ache that won’t quit? Reach out to us at Beacon PT for an evaluation and guided treatment plan!

Sources

Scott A, Rees JD. Basic Science and Pathophysiology of Tendons. In: Simoneau GG, ed. Physical Therapy Management of Tendinopathies. Academy of Orthopaedic Physical Therapy, APTA, Inc.; 2022:5-25.