The Three Forces Your Tendons Hate (and How to Keep Them Happy)

You don’t really think about your tendons until they start complaining. Maybe it’s that sharp tug near your elbow when you lift a box, or the ache in your heel after a run. You stretch, you rest, maybe you Google “tendon pain,” and then—boom—you’re suddenly an expert in tendinitis.

But here’s the truth: most tendon pain isn’t bad luck or age. It’s physics. Tendons are strong, but they hate certain kinds of mechanical stress—forces that wear them down faster than they can recover. Learn to spot these forces, and you can prevent most tendon troubles before they start.

Let’s meet the three forces that tendons hate.

1. Compression — The Squeeze That Suffocates

Imagine pinching a garden hose while water’s running through it. That’s what happens when a tendon gets squished between bones or tissues—it’s still working, but circulation is reduced, and stress builds up in all the wrong places.

Where it happens:

• The shoulder (the rotator cuff getting pressed under the shoulder blade)

• The Achilles tendon at the back of your heel

• The hip or knee when joint angles get too deep or awkward

Why it’s bad: Compression reduces blood flow and irritates the tissue. Over time, that “just a pinch” turns into inflammation and micro-damage.

What to do instead:

• Avoid working through painful joint angles where you feel pinching.

• Strengthen in mid-range positions first.

• Improve posture and mobility so tendons aren’t constantly jammed.

Think of it like traffic: if the lane is narrow, even light traffic causes a jam. Open up the lane, and things move smoothly again.

2. Friction (or Shear) — The Rub That Irritates

Tendons aren’t designed to slide endlessly like cables in a machine. They’re supposed to glide a little—not rub and grind every time you move. When that happens, the outer layer of the tendon or its sheath becomes irritated, like a rope rubbing over a rock again and again.

Where it happens:

• The wrist and hand (think typing, drumming, or climbing)

• The outer knee (runner’s knee)

• The ankle (from repetitive side-to-side movement)

Why it’s bad: Friction creates heat and inflammation. Over time, the tendon sheath gets thick and painful—a condition often mistaken for “tendinitis.”

What to do instead:

• Mix up your movements. If you’re repeating the same motion a hundred times a day, vary your grip, angle, or rest.

• Improve technique—small form errors add up to big problems.

• Use mobility drills to keep tissues sliding cleanly, not grinding.

Remember: tendons love smooth gliding, not constant rubbing.

3. Tensile Overload — The Stretch That Snaps

This one’s the classic. Tendons attach muscle to bone, so they take the brunt of your strength. When you suddenly lift too heavy, jump too hard, or increase training volume too fast, the tendon fibres are stretched beyond what they can handle.

Where it happens:

• The elbow (“tennis elbow” or “golfer’s elbow”)

• The Achilles or patellar tendon

• The hamstring or shoulder during explosive movements

Why it’s bad: Muscles adapt to training in weeks; tendons take months. Push too hard too soon, and they can’t keep up. Microtears and chronic pain follow.

What to do instead:

• Increase load slowly—no more than 10% per week for most training.

• Include eccentric work (slow lowering movements), which builds tendon resilience.

• Prioritise rest and recovery—tendons heal slowly, so be patient.

In short: your muscles might be ready for more weight, but your tendons are still catching up.

The Big Picture: Tendons Don’t Hate Movement—They Hate Neglect

Here’s the paradox: tendons actually need stress to stay healthy. Without movement and load, they weaken. But the key is the right kind of stress—gradual, controlled, and in good alignment.

Think of your tendons as patient teachers. They’ll adapt beautifully if you give them time, but they’ll punish you if you skip steps. Manage compression, reduce friction, and respect tensile load, and your tendons will reward you with strength, speed, and pain-free motion for years.

Quick Tendon Care Checklist

✅ Move through pain-free ranges✅ Strengthen slowly, especially in the lowering phase✅ Vary your movements and grips✅ Rest before pain becomes chronic✅ Stay consistent—tendons love routine more than surprises