Altus Forearm Flexor The Altus Forearn Flexor Forearm and hand strength are crucial to peak performance in numerous sports activities, e.g. golf, baseball, tennis, football and bowling. With that in mind, Altus Athletic has designed a full line of superior products tailored to the user39s size and fitness level. Lightweight and portable, the Altus Forearm Flexor allows you to build strength and flexibility for your forearms and hands at home or on the go.