Strengthening arms and shoulders

Arm and shoulder strength is nessessary fo many sports.
Sportsperson have to learn to use not only the deltoids, but also the latissimus. To understand the role of the latissimus inthe extension of the arms, lift your arms over your head. After some time, the upper arm muscles feel heavy, fatigued and ready to collapse, a sensation often experienced by many players. If the arms are extended not merely from the armpit, but freom the latissimus dorsii, they do not feel fatigued, instead, they are energised. Arms move from the latissimus when the scapula (shoulder blade) moves in. This action gives a greater freedom to the shoulders and makes the arms feel well extended.
From the book “Yoga for sports” written by B.K.S.Iyengar.