Rectus sheath

Biceps femoris muscle

Superior rectus muscle

Rectus capitis lateralis muscle

Bradley Blair Osteopath on Instagram: "The pectoralis major is a paired, superficial muscle located on the anterior surface of the thoracic cage. If you’re a gym lover, you’ll hear these muscles also being referred to as the pecs muscles. The pectoralis major has a broad origin, based on which it is divided into three parts: clavicular part, sternocostal part and abdominal part. All three parts converge laterally and insert onto the greater tubercle of humerus. Origin: Clavicular part: anterior