Groundwork is the last think that a martial artist associates with Karate. However, Karate has his decent share of Ne-Waza (ground techniques, 寝技). Such techniques are borrowed from Japanese Ju Jutsu and Judo, but aren’t practiced a lot for one simple reason: Karate avoids getting the practitioner to intentionally bring the fight to the ground.
That being said, there are some style such as Wado-Ryu that give grappling and wrestiling just as much importance as kickboxing, if not more. Besides, you still need to know what to do when taken down.
Grappling techniques include pins (Osaekomi-Waza - 抑込技)…:
- Kesa-Gatame, scarf hold
- Kuzure-Kesa-Gatame, broken scarf hold
- Ushiro-Kesa-Gatame, reverse scarf hold
- Kata-Gatame, shoulder hold
- Kami-Shiho-Gatame, upside hold, upper four quarter hold down
- Kuzure-Kami-Shiho-Gatame, broken upside hold, broken upper four quarter hold down
- Tate-Shiho-Gatame, vertical upside hold, vertical four quarter hold
- Yoko-Shiho-Gatame, side upside hold, side four quarter hold
- Uki-Gatame, floating hold
…chokes (Shime-Waza - 絞技)…:
- Do-Jime, trunk choke
- Gyaku-Jūji-Jime, reverse cross choke
- Nami-Juji-Jime, normal cross choke
- Kata-Juji-Jime, half cross choke
- Hadaka-Jime, naked choke
- Kata-Ha-Jime, single wing choke
- Kata-Te-Jime, one-hand choke
- Okuri-Eri-Jime, sliding lapel choke
- Ryo-Te-Jime, two-hand choke
- Sankaku-Jime, triangle choke
- Sode-Guruma-Jime, sleeve wheel choke
- Tsukkomi-Jime, thrust choke
…and locks (Kansetsu-Waza - 関節技):
- Ashi-Garami, leg lock, leg entanglement
- Ude-Garami, americana, arm entanglement
- Ude-Hishigi-Juji-Gatame, arm bar, back-lying perpendicular arm bar
- Ude-Hishigi-Ashi-Gatame, leg arm bar, side-lying arm bar
- Ude-Hishigi-Hara-Gatame, side-extended arm bar
- Ude-Hishigi-Hiza-Gatame, knee arm bar
- Ude-Hishigi-Sankaku-Gatame, reverse triangle, triangular arm bar
- Ude-Hishigi-Te-Gatame, devil’s handshake, hand lock
- Ude-Hishigi-Ude-Gatame, arm lock
- Ude-Hishigi-Waki-Gatame, armpit arm lock
However, I want to stress out that Karate groundwork is way underdeveloped compared to modern grappling system, such as BJJ, or even Judo (consider that the videos linked here show techniques performed by Judokas, not Karatekas). You can learn effective grappling to go against the average Joe, but it’s still basic work. If you intend to develop good grappling condider the aforementioneds BJJ and Judo.