5. Deep Front Line

DFL - posterior labelled DFL - side with line dfl labelled front

The Deep Front Line (DFL): a break down in the core of your body

Osteitis Pubis develops when biomechanical weaknesses in the body overload the adductors. The most common biomechanical flaws that we see to some OP patients are

  • Hip drop whilst running
  • Over pronation/supination
  • Anterior pelvic tilt
  • Knocked knees/bowed legs

Unfortunately these conditions are treated as separate problems. Tight hip flexors cause your APT, flat feet causes over pronation, a weak gluteus medius causes a hip drop.

But what if there was a common thread that tied all these conditions together?

What if this same ‘thread’ is at the center of Osteitis Pubis? This thread is the deep front line; the most important fascial/muscular chain in your body

The Deep Front Line: the rails of your body

Your body is a moving machine. Like a train on its tracks our ‘moving machine’ only works well when it moves within its limits. If you pull your leg back to kick a ball, and your hip slightly dislocates out of its socket, that ball isn’t going very far. Your DFL sits in your central axis; it is a fascial connection of all the muscles responsible for keeping your entire body stable and upright. It holds you in the ‘rails’ of good posture. Within these ‘rails’ your joints, ligaments, muscles and tendons are balanced. Joints remain firmly in their sockets, load is distributed evenly across the body and no one area is overused.


Deep Front Line active: The body is held tall.

Poor Shoulder Posture

Inactive Deep Front Line: The body loses its ‘midline’.


Parts of the DFL

  • The arch of your foot (deep toe flexors),
  • Knee/femur (adductors),
  • Pelvic girdle (pelvic floor and hip flexors)
  • Lower back (top of hip flexors and diaphragm)
  • Ribcage (thoracic core and diaphragm)
  • Neck and skull (deep neck flexors, TMJ muscle).

The muscles in brackets individually stabilise a specific joint; leading to the common misconception that you can strengthen one muscle to fix a joint problem. However it’s the DFL which connects and co-ordinates all the muscles together.

None of these muscles are actually strong enough to stabilise their individual joints without help. If your arch collapses (weak toe flexors) than your adductors will be unable to stabilise your femur; and your knee will suffer. If your pelvis is unstable (pelvic floor and hip flexor weakness) than your adductors will struggle to stabilise your hip in the socket.

It is the fascial connection between all these stabilising muscles; the DFL, which ensure the stability of all these joints. The sum is greater than its parts. The DFL enables you to move your body smoothly and efficiently, as a whole. When you stabilise your neck it’s the DFL, automatically pulling your ribcage and lower back into position to de-load the neck vertebrae and advantage the deep neck flexors.

The relative weakness of each stabilising muscle is negated when connected by the DFL.

How a collapsed Deep Front Line causes Osteitis Pubis

The Deep Front Line stabilises your body towards your central axis; keeping you balanced and in good posture. This helps distribute load evenly across your entire body. When its dysfunctional your body, and your posture begin to collapse. Where moving ‘outside the rails’ of our body. Now muscles and joints are being moved in unstable, overloaded patterns. Joints get worn out, muscle fatigue, Osteitis Pubis develops.

As we’ve established, OP is an overuse injury caused by flawed biomechanics. In OP we see a breakdown in two specific areas of the DFL; the Deep Toe Flexors which control he arch of the foot and the Pelvic Floor/Hip Flexors/Diaphragm which control the pelvis and lower back. Dysfunction in these areas lead to the common biomechanical flaws of OP

  • Hip drop whilst running
  • Over pronation/supination
  • Anterior pelvic tilt
  • Knocked knees/bowed legs

Weak arches cause Osteitis Pubis


When your tibialis posterior is active, your arch draws up and your ankle is in ‘neutral’.


If your tibialis posterior is inactive, the arch collapses, and the Deep Front Line is weakened.

The deep toe flexors are a group of muscles which live deep under the calves on the back of the tibia. The foot is not a solid structure like your femur. It is made up of 26 floating bones held together by ligaments and tendons. The tendons of the deep toe flexors attach to 8 of these bones, most of which live in the mid foot (where your arch is). Your deep toe flexors are responsible for drawing up and releasing your arch.

The deep toe flexors are vital to running and walking. When you’re running at full speed, your foot strikes the ground at a force of approximately 2.5 times your body weight. If you weigh 70kg that’s 175kg per foot strike. Your feet, your calves and particularly your deep toe flexors play a vital first stage in dissipating that load. Unfortunately when the deep toe flexors are dysfunctional that load simply transfers further up the leg to your adductors.

The two most common types of deep toe flexor dysfunction are over pronation and over supination. In over pronation the deep toe flexors are stretched and weak. Failing to draw up the arch, the ankle rolls in at high speed, dragging the knee with it.

In over supination the opposite occurs. The deep toe flexors are short and tight, making the arch high and rigid. Now when the foot hits the ground the arch cannot release, unable to take the pressure of your body like a spring. Instead the rigid arch forces you to roll onto the outside of the foot, dragging the knee outwards as well.

Whether its over pronation or supination the problem is the same. The deep toe flexors are not stretching, contracting and distributing foot striking ground force effectively. Instead they are just sending the load towards the adductors. Additionally by dragging the knee out of position they are increasing the load on the adductors, as they now need to also help pull the knee back into alignment.

This is all bad news for your adductors, which buckle under this increased workload and eventually develop OP.

Unstable pelvis and Osteitis Pubis

Anterior Pelvic Tilt Bad Posture

Anterior Pelvic Tilt (APT)

An Anterior pelvic tilt is when the front of your pelvis dips forward, increasing curve (and pressure) in your lower back and jamming your sacroiliac joint. This increased arch is usually caused by over tightening in the psoas muscle (hip flexor) and weakness in the glutes and core.

Illiopsoas Hip Flexor Psoas

Illio-Psoas – Primary hip flexor

As your pelvis dips forward it jams the hip joint. In response you will turn out your feet, opening up your hips and reducing pressure on the hip joint. Unfortunately turning out your feet over stretches your adductors. Additionally because the pelvis is dipping forward, the majority of the weight of the spine and upper body is now being sent into the front of the body. Unfortunately again it’s your adductors which is left to bear the burden of this load.

Everything is inter-connected

An anterior pelvic tilt encourages you to turn out your feet. Turning out your feet whilst running will encourage you to over-pronate. Of course if you have poor proprioception (balance), you may turn your feet out to provide more balance. Of course turning out your feet reduces tension in the pelvis; causing it to tip into an anterior pelvic tilt.

And now you can see the folly in trying to fix one area on its own. The moves in functional chains; fixing one area will only create issues further up and down the chain. Full functional rehab which focuses on re-establishing the stabiliSing role of the deep front line is one of the most important steps in recovering from Osteitis Pubis.

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