Glossary of Judo terminology
Prohibitions regarding junior age groups (Tachi shobu, Nage waza)
In addition to the general competition prohibitions, junior competitions also impose the following prohibitions in the interest of safety.
Grasping the back of the opponent's collar, the back, or belt ... "Shido" (Instruction / Light penalty)
Actions such as applying a Waza with an arm around the opponent's neck, or grasping the opponent's collar and pulling his uniform over his head, etc., will draw a penalty, and contestants are therefore forbidden to grasp the opponent's back or belt.
However, Tori (Player executing technique) is allowed to grasp the back of Uke (Player receiving opponent's attack) collar, his back, or belt at the moment when executing a Waza (1 to 2 seconds), or while hopping on one leg with the other leg in an Uchi-mata (Inner-thigh reaping throw) posture. Doing so at any other time will draw a "Shido" (Instruction / Light penalty).
Although grasping the back of the opponent's collar is permitted in junior high school competitions (depending on skill level of the contestants), continuing the grasp beyond the midline will draw a "Single sleeve & Single collar" penalty (6 seconds).
Performing a Seoi-nage (Shoulder throw) with both knees on the floor ... "Chui" (Light penalty) or higher penalty
Performing a Seoi-nage (Shoulder throw) with both knees on the floor could injure Tori (Player executing technique)'s cervical vertebrae and Uke (Player receiving opponent's attack) knee joints, and this action is therefore prohibited, as is a Seoi-nage (Shoulder throw) with both knees nearly touching the floor. Such actions will draw a "Chui" (Light penalty) or higher penalty.
Grabbing the opponent's legs in an abrupt motion ... "Chui" (Light penalty) or higher penalty
Grabbing an opponent's legs unexpectedly could cause the opponent to fall backwards, possibly causing injury. In junior high school competitions, however, contestants may grasp the opponent's lapel or sleeve with one hand when performing a Kibisu-gaeshi (Heel trip) or Kuchiki-taoshi (One-hand drop).