Open Exercise

Development draft, v0. Formats and IDs may change.

Catalogue

Isometric Leg Extension

oec:isometric-leg-extension

An isometric isolation exercise where the quadriceps contract against fixed resistance without movement at the knee joint.

Generated by gemini-3.8-flash from the sources below. No person has checked this record. Don't rely on it for safety.

Also called: Leg Extension Isometric Hold, Leg Extension Hold, Isometric Quad Extension, Leg Extension Isometric

How to do it

Setup

  1. Sit on the leg extension machine with your back firmly against the backrest.
  2. Align your knee joints with the machine's axis of rotation.
  3. Position the shin pad across the lower shins just above the ankles, and grip the side handles firmly.

Movement

  1. Extend your knees to the prescribed joint angle (commonly 45 to 60 degrees of flexion).
  2. Hold this fixed position under tension against the resistance for the targeted duration.
  3. Maintain steady quadriceps contraction without letting your hips lift or the weight drop.
  4. Carefully lower the weight back to the starting rest position under control once the hold is complete.

Breathing

Breathe continuously and evenly throughout the hold; avoid holding your breath.

Cues

  • Lock your hips down into the seat
  • Squeeze your quads hard
  • Stay motionless at the target angle

Common faults

Lifting the pelvis and lower back off the seat to leverage body weight.
Grip the machine handles firmly to anchor your hips firmly into the cushion throughout the hold.
Holding breath and bearing down during the contraction.
Maintain rhythmic, controlled diaphragmatic breathing for the duration of the set.
Allowing the leg position to drift downward as fatigue sets in.
Hold a steady target joint angle; terminate the set when you can no longer maintain the required angle.

Safety

  • If using for patellar tendon rehabilitation, perform holds at mid-range angles (typically 45-60 degrees of knee flexion) rather than full terminal extension to reduce patellofemoral joint stress.

Muscles

  • Rectus femoris prime mover
  • Vastus lateralis prime mover
  • Vastus medialis prime mover
  • Vastus intermedius prime mover
  • Rectus abdominis stabilizer

Joints

  • Knee: Isometric stabilization
  • Hip: Isometric stabilization

Details

Movement
Knee extension isolation
Modality
Rehabilitation, Strength, Hypertrophy
Mechanics
isolation
Force
static
Laterality
bilateral
Kinetic chain
open
Level
beginner
Equipment
Selectorized machine or Plate-loaded machine
Record
Duration and Load
Load
external, weight stack

Related

Sources

This record: CC-BY-SA-4.0.

Data

isometric-leg-extension.json