// Muscle Spindles vs Golgi Tendon Organs: How Understanding These Receptors Can Transform Your Yoga Teaching //

As yoga teachers, we often talk about “releasing,” “softening,” or “deepening into the stretch”, but behind these cues are incredible neurological mechanisms that govern how our muscles respond to movement and stretch. Two key sensory receptors play a huge role in this process: the muscle spindle and the Golgi tendon organ (GTO).

Understanding how these receptors work can help you sequence and cue more effectively, and create a safer experience for your students.

The Muscle Spindle

What it is:
The muscle spindle is a sensory receptor located within the belly of the muscle. It’s sensitive to changes in muscle length and the speed of that change.

How it works:
When a muscle is stretched too quickly or too far, the muscle spindle is activated and sends a message to the spinal cord saying, “Hey, we’re stretching too fast!” The spinal cord responds by contracting that same muscle to protect it from over-stretching.
This reflex is called the stretch reflex.

In yoga:
If a student pushes too quickly for example, into a hamstring stretch in a forward fold, the muscle spindle kicks in, causing the hamstrings to reflexively tighten. This is why sometimes, pushing harder doesn’t lead to a deeper stretch it actually leads to more resistance, stress to the tissue and a reduction in the beneficial outcome.

How to work with it:

• Cue for the student to enter the posture slowly and mindfully. Encourage students to enter poses gradually, giving the muscle spindle time to adapt.

• Encourage the students to use their breath as a guide and an entry point for the stretch. Sustained, gentle stretching over 20–30 seconds allows the initial spindle activity to ease off, helping the muscle relax.

• Avoid fast, strong, aggressive adjustments. Quick or forceful stretches can trigger the stretch reflex, making the pose feel restricted or tight.

The Golgi Tendon Organ

What it is:
The Golgi tendon organ (GTO) is located at the junction between muscle and tendon. It’s sensitive to tension created in the muscle, not length.

How it works:
When the GTO senses sustained tension in a muscle, it sends signals to inhibit that muscle’s contraction, effectively telling it to let go to prevent potential injury.

In yoga:
Holding a pose for a longer duration, or applying a gentle isometric contraction (like engaging the quads in a forward fold by lifting the knee cap up), can activate the GTO, allowing the muscle to relax more deeply afterwards. This is why sometimes after holding or contracting a muscle gently, you can sink deeper into the pose.

How to work with it:

• Incorporate gentle contractions. For example, in a seated forward fold, cue students to press their heels down and lightly activate their quads for 5 seconds before softening, this can trigger GTO response and allow the hamstrings to lengthen more effectively.

• Use longer holds. Yin or restorative practices naturally make use of this principle. Sustained tension over time encourages deeper release.

• Balance activation and release. This neuromuscular interplay allows for safer, more supported flexibility.

🧘‍♀️ Applying This Knowledge to Sequencing and Cueing

1. Warm up before deep stretching.
   Gentle movement and slower, progressive stretching reduce the muscle spindle’s “alarm,” preparing tissues for deeper work.

2. Add more to your stretches.
   Cue for students to activate the muscles whilst stretching, allowing for a gentle contraction and then a sustained stretch will then take advantage of both the spindle relaxing over time and the GTO’s inhibitory effects.

3. Use PNF-inspired techniques (Proprioceptive Neuromuscular Facilitation).

   • Example: In Supta Padangusthasana (reclined hamstring stretch), have the student gently press their leg into the strap (activating the hamstrings) for 5 seconds, then exhale and relax to go deeper.

4. Cue patience, not force or ego.
   Instead of “push deeper,” try cues like:

   • “Take your time, let the tissues change.”

   • “Breathe into the sensation and allow the muscle to soften.

   • “Gently activate, then release to go a little further.

Why This Matters:

Understanding the difference between the muscle spindle and the GTO helps you work with the body’s nervous system, not against it. This knowledge can help you:

• Create more effective flexibility gains over time

• Prevent over stretching injuries

• Empower students to understand their bodies more deeply

• Offer intelligent, anatomy-informed cues that elevate your teaching