From Dragon Ball Encyclopedia, the ''Dragon Ball'' wiki
Yamucha places one hand forward with the other gripping the arm for either support or delivering more energy flow into the one hand. He forms yellow-orange energy ball like a small Genki Dama and manipulates it by placing his two first fingers upward from the palm as if he is doing the Explosive Wave. Using the Sokidan, Yamucha can hit the enemy several times with something of a physical attack only from long range. It explodes on the last strike.
Yamucha used this attack in his fight against Shen.
Yamucha used this attack in Dragon Ball Z: The Tree of Might and Dragon Ball: Ossu! Kaette Kita Son Goku to Nakama-tachi!!
The Sokidan appeared in Dragon Ball Z: Supersonic Warriors 2, Dragon Ball Z: Budokai 2, Dragon Ball Z: Budokai Tenkaichi 2, and Dragon Ball Z: Budokai Tenkaichi 3. Yamucha still calls it the Spirit Ball in Budokai Tenkaichi 2 and Budokai Tenkaichi 3.
- The English translators mistranslate it as the Spirit Bomb in the remastered version of Dragon Ball Z.