Striking energy achieved by knee strikes, elbow blows, head butts and fist punches

Several studies have examined the force achieved by elite or professional fighters by fist punches and knee strikes, but only a few studies investigated the performance of average young persons without martial arts or boxing experience. Ten healthy men and ten healthy women were required to strike a padded force-measuring plate at a right angle ten times as hard as possible with head butts, fist punches, elbow blows, and knee strikes. Age, sex, body size, and mass were compared to the impact forces generated by the different striking modes. The highest striking force was achieved with knee strikes for both men and women; interestingly, women tended to achieve higher impact forces with knee strikes than men (maximum 2560 N vs 2521 N). Women displayed similar results with fist punches and elbow blows (approx. 500-550 N), whereas men performed best in elbow blows (median 922 N), followed by fist punches (median 721 N), and head butts (median 652 N), with the latter surpassing the women's median head butt striking force of 372 N. Men achieved higher striking forces than women with head butts, fist punches and, elbow blows but not with knee strikes. Striking force increased with body mass. The average striking force of head butts, fist punches, and elbow blows was below the mean fracture threshold of approximately 1350 N as stated in the literature, knee strikes, on the other hand, easily surpassed the proposed fracture threshold.