Description: Segment 1 Title: Five Male Acrobats. Radiograms of shoulder joint are shown as well as somersaults in slow motion. Intertitle: Radiogram of shoulder joint, arm dependent. The lower border of the anatomical neck rests one third of the way up the glenoid cavity. An x-ray shows the shoulder joint. Intertitle: Radiogram of shoulder joint, arm horizontal. The viewer is asked to observe the amount of humeral articular surface which has escaped from the glenoid cavity. Intertitle: Radiogram of shoulder joint, arm erect. There is a medium shot of an acrobat, head and shoulders. Intertitle: Absence of platysma. There is a shot of the head and shoulder relaxed. Intertitle: Platymsa. There is a shot of a head and shoulders tensioned to show platysma. Intertitle: Observe the action of serratus anterior and lasissimus dorsi, especially the latter coming into play when the arms are lowered against resistance. Time start:00:00:00:00 Time end: 00:04:45:07 Length:00:04:45:07 Segment 2 There is a shot of an acrobat with arms raised from the ventral, side and dorsal views, other movements are also shown from various angles, such as stretches and moving against resistance. Intertitle: Action of tensor fasiae latae, ilio-tibila band, gluteal muscles while standing on one leg. Shots of the leg muscles while the acrobat rises one leg. A handstand is seen, showing the serratus anterior. Time start:00:04:45:07 Time end: 00:09:49:24 Length:00:05:04:17 Segment 3 The acrobats perform various jumps to illustrate muscle groups working. Intertitle: Monkey jump or flip-flap. Intertitle: Butterfly - an acrobat performs a butterfly jump. Intertitle: Handspring. An acrobat performs a handspring. Intertitle: Pyramid. The weight of the two centre figures is placed on the occiput of the inverted figures, necessitating powerful contraction of the whole erector spinae muscle. Acrobats are seen creating a pyramid. Time start: 00:09:49:24 Time end: 00:15:19:18 Length: 00:05:29:23