What is a Tendon?
Tendons play a vital role in how our bodies move, absorb force, and stay stable. These tough, fibrous bands connect muscle to bone, transmitting the power generated by muscles into precise movement at the joints. While incredibly strong and built to handle load, tendons are not immune to injury — especially when stressed by overuse, poor biomechanics, sudden trauma, or age-related changes. Understanding the different types of tendon injuries is key to managing pain, restoring function, and preventing future problems.
What Are Tendon Injuries?
Tendon injuries occur when the tendon — the strong connective tissue that links muscle to bone — becomes damaged, overloaded, or disrupted. These injuries can develop gradually over time or happen suddenly due to trauma. They’re incredibly common across all age groups and activity levels, and they often share overlapping symptoms such as pain, swelling, and reduced movement or strength.
Sprain or Strain?
Strain
A strain is an injury to a muscle or tendon (the tissue that connects muscle to bone). It typically occurs when the muscle or tendon is overstretched or torn, often from sudden movement, lifting something too heavy, or overuse during sport or activity.
Common examples:
-
Hamstring strain
-
Lower back muscle strain
-
Achilles tendon strain
Sprain
A sprain is an injury to a ligament — the strong connective tissue that connects one bone to another at a joint. A sprain occurs when a ligament is stretched, twisted, or torn, usually from trauma such as a fall, awkward landing, or sudden change in direction. For more information about ligament sprains why not visit our dedicated page to ligaments injuries
Common examples:
-
Ankle sprain
-
Wrist sprain
-
Knee ligament sprain (e.g., ACL)
Tendon Tears
When most people hear “tendon tear,” they picture something dramatic — a loud snap mid-match, or suddenly being unable to move a limb. And yes, sometimes it really is that clear-cut. But in reality, not all tendon tears are catastrophic, and many don’t require surgery. Some are just small frays in the fibres, while others involve a full rupture where the tendon has completely pulled away from the bone.
Just like muscle strains, tendon tears are typically graded by severity — and that grading system helps guide both diagnosis and treatment planning.
Ever wondered why anti-inflammatories like ibuprofen or naproxen don’t seem to touch your tendon pain?
It’s probably because the issue isn’t inflammation at all. Despite the name, most long-term tendon problems aren’t inflamed — they’re worn, overloaded, or structurally changed. That’s why popping anti-inflammatories often does little more than mask symptoms (if that). If the underlying tendon is degenerating or overloaded, the fix isn’t in a pill — it’s in understanding the problem properly and rebuilding strength the right way.
Still interested? Keep reading — this is where things start to make sense.
NO TENDON TEARS - Tendinopathy - Tendonitis - Tenosynovitis - etc etc
As research moves on, so does the way we define injuries — and tendon problems are no exception. What we used to lump together under a single label now often gets broken down into more specific diagnoses. And in many ways, that's helpful — because the more accurate we can be, the better we can guide treatment.
But there's a downside too. The more terms that get introduced, the more confusing things can become — especially when not all clinicians are working off the same page. You might be told you’ve got "tendinitis" by one person, "tendinopathy" by another, and hear "tendinosis" thrown in for good measure. Understandably, this can make patients feel lost before they’ve even begun to recover.
So what do these terms actually mean? And more importantly, do the differences matter to your recovery?
Tendinopathy - The Umbrella Diagnosis
Tendinopathy is the general term we now use to describe pain, stiffness, or dysfunction in a tendon — usually from overuse, repetitive strain, or a breakdown in the way the tendon repairs itself. Importantly, this isn’t about inflammation in the traditional sense (even though it may feel hot, sore, or swollen). Instead, it’s more about wear and tear, and how well — or badly — the tendon has adapted over time.
What’s actually going on inside the tendon? Structurally, the fibres can become disorganised and less springy. The tendon might thicken, develop tiny new blood vessels (which aren’t necessarily helpful), and lose its ability to handle load efficiently. This is why tendinopathy often builds gradually — especially in people who are active or increasing their training load.
Clinicians now tend to talk about tendinopathy as existing along a continuum, with three overlapping stages:
Reactive tendinopathy:
Usually the first response to a sudden spike in load — like taking up a new sport or increasing your mileage too quickly. The tendon becomes temporarily swollen and sensitive, but these changes are often reversible if caught early.
Tendon disrepair:
If the tendon continues to be overloaded, it starts showing early signs of breakdown. The collagen (which gives the tendon its strength) begins to separate and lose alignment, making it less robust.
Degenerative tendinopathy:
Over time, if the problem isn’t addressed, the tendon can start to show more significant wear — with cell death, tissue thinning, and a loss of structural integrity. At this stage, recovery takes longer and the risk of a partial or full tear may increase.
Tendonitis (or Tendinitis)
This is the term most people have heard — and it’s still commonly used in everyday conversations and GP letters. Technically, it refers to inflammation of a tendon, usually after a short-term overload or injury.
The issue is, most ongoing tendon problems aren’t actually inflamed. What’s happening inside the tissue is usually more about degeneration than inflammation — especially in long-standing cases. That’s why terms like tendinopathy or tendinosis are now preferred by most specialists. They're simply more accurate descriptions of what’s going on.
That said, there are times when true inflammation can be part of the picture — especially in acute tendon injuries, or in certain autoimmune or inflammatory conditions (like rheumatoid arthritis). But for the majority of people turning up with tendon pain that’s been niggling for weeks or months, “tendonitis” is likely not the most accurate label anymore.
So, if you've been told you have tendonitis, don’t panic — but do ask what exactly that means for your rehab. Getting the right name on the diagnosis can make a big difference to how it's treated.
Tendinosis
Tendinosis is what we call it when a tendon has gone through long-term structural change — not from a sudden injury, but from repetitive strain or chronic overload over time.
Unlike the old idea of “inflammation” (which is more short-lived), tendinosis is degeneration. That means the collagen fibres that make up the tendon have started to lose their neat, rope-like structure. You might see thickening, disorganisation, or even small tears on a scan — but no redness or swelling that would suggest classic inflammation.
Some clinicians use “tendinosis” to describe the later stages of tendinopathy — the point where healing has stalled and the tendon simply isn’t coping well with load anymore. In other words, it’s not just irritated — it’s worn out.
An example of this would be if you’ve had ongoing Achilles pain for months, it’s thickened, stiff in the morning, and grumbles every time you run. That’s textbook tendinosis.
Tenosynovitis
This one's a bit different. Tenosynovitis refers to inflammation of the sheath that surrounds a tendon — not the tendon itself. Some tendons, especially in the wrist, hand, and ankle, sit inside fluid-filled tunnels called synovial sheaths. These help the tendon glide smoothly when you move. But if that sheath becomes irritated or inflamed, things start to go wrong.
You might notice pain, swelling, stiffness, or even a clicking or catching sensation as the tendon tries to move through a now-narrowed space.
There are two main types:
Non-infectious tenosynovitis:
This is by far the most common. It’s usually linked to repetitive strain — think typing, lifting, or gripping. Common examples include De Quervain’s (pain on the thumb side of the wrist) or trigger finger, where the finger catches or locks when you try to straighten it.
Infectious tenosynovitis:
Far less common, but much more serious. This can happen when bacteria enter the tendon sheath, often through a cut or puncture wound. It causes intense pain, redness, and swelling — and needs urgent medical attention, often involving antibiotics or surgery.
If you’ve ever had pain on the thumb side of your wrist when lifting your baby, using a screwdriver, or even texting, there’s a fair chance it’s non-infectious tenosynovitis.
Paratenonitis (also called Peritendinitis)
This one's easy to miss — but it crops up more often than you'd think. Paratenonitis is the inflammation of the paratenon — a thin layer of connective tissue that surrounds some tendons, especially those without a synovial sheath. One of the most well-known examples? The Achilles tendon.
Unlike tendinopathy, which involves changes within the tendon itself, paratenonitis affects the tissue around it. You’ll often feel a gritty, squeaky, or creaky sensation when moving the tendon — this is called crepitus — along with localised pain and swelling.
It’s usually triggered by overuse, friction, or poor training mechanics — like ramping up your running mileage too fast, switching shoes, or training on hard surfaces.
An example would be if a new runner develops pain and a grinding sensation over the back of their heel — often diagnosed as “Achilles tendinopathy,” but really it’s the paratenon that’s inflamed, not the tendon itself.
Tendon Subluxation or Dislocation
This one’s a bit more mechanical than degenerative. A tendon subluxation happens when the tendon slips out of its usual track or groove, either partially or completely. It's not torn — it’s just not where it should be.
This can happen for a few reasons: loose supporting ligaments, an old injury that’s never fully settled, or simply the way your anatomy is built. It doesn’t always cause constant pain, but it often shows up as a snapping, popping, or shifting sensation — sometimes only when the joint moves in a certain way.
It can come and go depending on position, activity, or muscle tension. For some people it’s just an odd quirk; for others, it can be painful, unsettling, or downright limiting.
One of the more common presentations of this would be the peroneal tendons snapping around the outside of the ankle when you twist or change direction quickly.
Calcific Tendinopathy
This is where calcium deposits build up inside the tendon itself, most commonly in the shoulder — particularly the supraspinatus tendon of the rotator cuff. It can appear gradually, or flare up suddenly when your body tries to reabsorb the calcium (that’s when it becomes extremely painful).
We’re still not entirely sure why this happens — it could be linked to poor blood supply, repeated overload, or just age-related changes. Often, people don’t even know they’ve got it until a scan shows it by chance. But when symptoms kick off, the pain can be severe — often worse at night or when lifting the arm overhead.
Example: A middle-aged person with no clear injury develops intense shoulder pain, can’t sleep on that side, and struggles to raise their arm. A quick X-ray shows a cloudy white patch over the tendon — calcium.
Tendon Adhesions
Adhesions are a common complication after tendon surgery or injury, particularly if the area has been immobilised for a while. They happen when scar tissue forms around or within the tendon, sticking it to nearby structures and stopping it from gliding freely.
This can cause stiffness, weakness, or restricted range of motion — even if the tendon itself has healed. It's most often seen in hand surgeries, rotator cuff repairs, and tendon repairs in the foot or ankle.
An example of this could be after surgery to repair a finger tendon, where the patient struggles to fully bend or straighten the finger. The repair is intact — but scar tissue has tethered the tendon to surrounding tissue, limiting movement.
Tendon Avulsion
A tendon avulsion is where the tendon rips away from the bone, sometimes taking a small chunk of bone with it. It’s usually the result of a sudden, powerful force — often during sport or a fall.
This isn’t the kind of thing that heals well on its own — especially if there’s a large gap between the torn tendon and its original attachment. Surgical repair is often needed, followed by a slow, structured rehab plan.
Example: A waterskier tears their hamstring clean off the sitting bone during a high-speed fall — or a gym-goer detaches their distal biceps tendon while deadlifting.
Tendon Tears
Not all tendon tears are the same. To make sense of them — and to guide treatment properly — we typically divide tendon tears into two main types: partial tears, where some of the tendon fibres remain intact, and full-thickness tears, where the tendon has completely torn through. Each comes with its own symptoms, levels of severity, and recovery timelines. Getting the classification right is a crucial step in figuring out what comes next.
Partial Tendon Tear
A partial tear means that only some of the tendon fibres are damaged — the rest are still intact and holding on. The structure hasn't completely failed, but it's no longer working at full capacity either.
In many cases, you'll still have decent strength and a fair range of motion, but you'll likely notice pain with specific activities, particularly anything that loads or stretches the tendon. It’s the sort of injury that can quietly simmer in the background for weeks or months — only flaring when pushed too hard.
These injuries can be subtle on examination and sometimes even missed on early imaging, especially if the symptoms aren’t severe. But left unmanaged, they can worsen over time or increase the risk of a full rupture.
Typical symptoms may include:
-
A deep, aching pain that worsens with use
-
Localised tenderness or swelling
-
Mild weakness or a feeling of “catching” during certain movements
-
Trouble with repetitive or overhead tasks
Common Examples:
-
Partial rotator cuff tear — difficulty lifting the arm or sleeping on that side
-
Patellar tendon fraying in runners or gym-goers doing a lot of jumping/squatting
-
Achilles tendon microtears — often following a sharp increase in running distance or intensity
Full-Thickness Tendon Tear
A full-thickness tear is where the tendon has torn all the way through — often separating completely from its attachment point on the bone. In simple terms, the muscle is no longer fully connected to the skeleton, which usually means a significant loss of strength or function.
These tears can happen in one of two ways:
-
Suddenly, from a traumatic injury or high-force movement (like lifting something heavy, falling awkwardly, or during explosive sport).
-
Gradually, in a tendon that’s already been weakened over time due to wear and degeneration — until one final load becomes too much.
In some cases, people hear or feel a "pop," followed by immediate pain and a sharp drop in function. Others don’t realise how severe the damage is until they notice major weakness or loss of movement days later.
Typical signs might include:
-
A sudden sharp pain or snapping sensation
-
Inability to lift, push, or weight-bear as normal
-
Visible deformity or "denting" where the tendon used to be
-
Significant weakness or altered movement pattern
Common Examples:
-
Complete Achilles tendon rupture — often occurs during sports involving sudden take-off or direction change
-
Full-thickness rotator cuff tear — typically presents with an inability to lift the arm overhead
-
Distal biceps tendon rupture — usually in heavy lifters or manual workers, especially during forced elbow extension under load
Summary
Understanding tendon problems isn’t just about where it hurts — it’s about what’s actually going on in the tissue. Sometimes the issue is inflammation, sometimes degeneration, and sometimes a tear — either partial or full. Getting the diagnosis right really matters, because treatment can vary hugely depending on the type and severity. A mildly irritated tendon might just need time, load management, and the right rehab plan. But a full-thickness tear could require surgical repair and a much longer recovery.
That’s why, if your symptoms aren’t improving — or something just doesn’t feel right — it’s worth getting checked by someone who understands how to assess tendon injuries properly. A clear diagnosis is the first step to getting the right outcome.
A Quick Note From Chris
It won’t surprise many of you to know that I don’t get any financial reward for writing and sharing these pages. I do it because I genuinely want to help people better understand their conditions and feel more in control of their recovery.
All I ask is that you don’t plagiarise or claim this work as your own — and if you’ve found it helpful, please consider sharing it with friends, family, or anyone else who might benefit from it. Follow my blog for regular updates on new topics, pages and future projects.
Thanks for reading — and for taking your health seriously.
Grow Your Vision
Welcome visitors to your site with a short, engaging introduction.
Double click to edit and add your own text.
Tendon Injury FAQ's
Why You Should Choose Chris Heywood Physio
The most important thing when seeking help is finding a practitioner you trust—someone who is honest, responsible, and clear about your diagnosis, the treatment you really need, and whether any follow-up appointments are necessary.
I’m not here to poach you from another therapist, but if you’re looking for a new physiotherapist in Northamptonshire or simply want a second opinion, here’s why many people choose to work with me (read my reviews):
Over 25 Years of Experience & Proven Expertise
With 25+ years of hands-on physiotherapy experience, I’ve built a trusted reputation for clinical excellence and evidence-based care. My approach combines proven techniques with the latest research, so you can feel confident you’re in safe, skilled hands.
Longer Appointments for Better Results
No two people—or injuries—are the same. That’s why I offer 60-minute one-to-one sessions, giving us time to:
-
Thoroughly assess your condition
-
Provide focused, effective treatment
-
Explain what’s really going on in a clear, simple way
Your treatment plan is tailored specifically to you, aiming for long-term results, not just temporary relief.
Honest Advice & Support You Can Trust
I’ll always tell you what’s best for you—even if that means you need fewer sessions, not more. My goal is your recovery and wellbeing, not keeping you coming back unnecessarily. I have low overheads nowadays and I do not have pre-set management targets to maximise patient 'average session per condition' (yes it does happen commonly and I hate it with a passion - read my article here)
Helping You Take Control of Your Recovery
I believe the best outcomes happen when you understand your body. I’ll explain your condition clearly, give you practical tools for self-management, and step in with expert hands-on treatment when it’s genuinely needed.
Looking for a physiotherapist who values honesty, expertise, and your long-term health?
Book an appointment today and take the first step towards feeling better.
Contact Info
On a Monday and Tuesday I work as a specialist contractor but I can still be contacted for enquiries. You are welcome to call but it is often faster for me to reply via a contact form or watsapp message, simply as my phone will be on silent in clinic. Either way, I will reply as soon as possible, which in the week, is almost always on the same day at the latest.
Clinic Opening Hours
The Clinic is located at 2 Old Road, Scaldwell, Northants, NN6 9LA - More info
Mon - Tues
Weds - Fri
Sat -Sun
Closed for Contract Work
0900 - 1330
Closed (Family Time!)
** Please note that online sessions can sometimes be arranged outside of normal clinical hours on request.**