The Internal And External Obliques

In this blog we investigate the external and internal obliques, named after the Latin obliquus, which means diagonal or slanted. When a personal trainer sets exercises that involve rotational movement of the torso, this will help train the internal and external oblique muscles.

THE ORIGINATION AND INSERTION OF THE INTERNAL OBLIQUES

The internal obliques are found deep in the abdominal wall and originate from the iliac crest, the lateral two-thirds of the inguinal ligament and a sheet of connective tissue in the lower part of the back known as the thoracolumbar fascia. They insert into the lower three or four ribs and the linea alba via aponeurosis.

THE ORIGINATION AND INSERTION OF THE EXTERNAL OBLIQUES

Located at the side of the trunk, the external oblique is one of the outermost of the abdominal muscles, originating from the lower eight ribs. The exterior obliques insert into the anterior half of the iliac crest and also into an abdominal aponeurosis – this terminates in the linea alba, which is a tendinous band that extends from the sternum downwards.

THE ACTION OF THE OBLIQUES

The obliques have the following actions:

• Compressing the abdomen by pulling the chest downwards
• Helping to support the abdominal viscera against gravity’s pull
• Providing stability and mobility when bending and rotating, whether standing, walking or running

All of these actions can easily be incorporated into an exercise programme set by a personal trainer.

The basic functional movement of the obliques includes any kind of digging or raking action as well as twisting and reaching for something, whether seated or standing.

COMMON EXERCISES FOR THE OBLIQUES

Because they are part of the muscles that make up the core, the obliques should not be under utilised, for example by sitting with a slumped posture, as this can affect the support of the spine.

A lot of clients may focus on training the rectus abdominus in a bid to gain a six-pack; however, fitness professionals should also run their clients through exercises that train the obliques to help strengthen and stabilise the core. Even though strong obliques may not be visible, they can benefit overall health and help training, for example by allowing a client to lift a heavier weight in resistance training.

Strengthening exercise include:

• Side bends
• Oblique crunches
• Reverse trunk twists
• Hanging leg raises
• Seated barbell twists

A personal trainer can also show clients how to carry out some useful side stretches using the obliques; these can help with flexibility and range of movement.

WHICH SPORTS USE THE OBLIQUES?

Training the obliques can help a fitness professional’s clients who are involved in sports or athletic activities such as:

• Rugby and other contact sports
• Golf and tennis
• Javelin, shot-put and pole vault
• Gymnastics and rowing

PROBLEMS ARISING FROM WEAK OBLIQUE MUSCLES

Because abdominal strength contributes to the stability of the lower spine, it’s important to have strong oblique muscles to avoid injury to this area.

A personal trainer should include exercises to strengthen the interior and exterior obliques in a client’s training routine, as well as those for the more obvious abdominal muscles.