Fig. 4.

a Trail knee flexion angle of players of all skill levels using all club types at the six major swing phases: address, top of the backswing (top-BS), middle of the downswing (mid-DS), impact, middle of the follow-through (mid-FT), and end of the FT (End-FT). Thick lines and thin lines represent the combined mean and standard deviation of all study groups, respectively [39–41, 44, 45, 47, 49]. Electromyographic activity (mean ± standard deviation) as a percentage of muscle activity during maximum voluntary contraction (%MVC) of muscles crossing the knee joint at five phases of the golf swing: BS, early-DS, late-DS, early-FT, and late-FT, reported by b Bechler et al. [53] and c Marta et al. [54]. Muscles analysed: biceps femoris (BF), semimembranosus (SM), vastus lateralis (VL), semitendinosus (ST), gastrocnemius medialis (GNm), gastrocnemius lateralis (GNl), vastus medialis (VM), rectus femoris (RF)