Scientist's Accidental Achilles Tendon Fix: The Science of Jerk and Isometrics

The Genesis of a Tendon Protocol

• 💡 The story begins with Dr. Håkan Alfredson attempting to rupture his own Achilles tendon to study healing, based on the principle that ruptured tendons heal faster than those with tendinopathy.
• 🎯 His method involved holding maximum weight and slowly lowering it, which unexpectedly fixed his Achilles tendon.
• 🚀 This accidental discovery became the basis for a new protocol, similar to methods previously used for racehorses.

Understanding 'Jerk' in Biomechanics

• ⚡ Jerk is defined as the rate of change of acceleration, a physical property crucial in understanding injuries.
• ⚠️ High jerk forces are experienced during rapid movements like a weightlifting 'catch' or the swing of a tennis racket, leading to injuries such as tennis elbow.
• 🤕 Similarly, dynamic movements in sports like jumping can cause jumper's knee due to these rapid acceleration changes.

The True Mechanism Behind Eccentric Training

• 🧠 The effectiveness of eccentric training was misunderstood; it wasn't the eccentric or concentric phase itself, but the tempo and velocity of the movement that mattered.
• 🔑 Heavy strength training, which requires slow movements, has a similar effect to eccentric training because it minimizes velocity.
• 🎯 The key insight is that keeping velocity at zero (isometric holds) maximizes load through the tendon cells.

Isometric Holds for Tendon Health

• ✅ The protocol emphasizes isometric holds by keeping the velocity of movement at zero, which provides significant load to the tendon.
• ⏱️ For healthy tendons, shorter isometric holds (1-10 seconds) are effective.
• 📈 For injured tendons, longer holds (around 30 seconds) are necessary to achieve even load distribution, as the injured tissue requires more time to relax and signal load.

Optimal Duration and Load for Tendons

• 🔬 Research shows that by 30 seconds, the force required to hold a tendon at a certain distance apart decreases by about 85%.
• 📉 Waiting until 2 minutes provides only an additional 15% diminishing return, making 30 seconds an effective duration for injured tendons.
• 🤏 The duration of the isometric hold also depends on the size of the tendon; larger tendons like the Achilles require longer holds than smaller flexor tendons in the fingers.