Optimal pelvic alignment is essential for mechanical efficiency during sport and exercise. Incorrect pelvic alignment, most notably anterior pelvic tilt can compromise muscle performance and can increase the likelihood of a number of lower limb pathologies.
Anterior pelvic tilt occurs when the pelvis rotates anteriorly around the hip joint along a transverse axis. This creates excessive hip flexion and an excessive loordosis at the lumbar spine in a static posture. There are a number of different causes of anterior pelvic tilt. This article will focus on anterior pelvic tilt as occurs through muscle imbalances, its implications and various management options.
Implications of Poor Pelvic Alignment
First of all, it is important to recognise that a small amount of anterior pelvic tilt is the normal position for the pelvis. This angle is approximately 5-degrees in males, and slightly greater in females to between 7-10-degrees. Generally speaking, it is only when this angle is dramatically increased that it starts to become symptomatic.
- As previously mentioned, excessive anterior pelvic tilt is associated with an increase in the degree of lumbar loordosis. It has been suggested anecdotally, that this can create repetitive impingement of the vertebral facets in the lumbar spine which can then result in lower back pain in runners (Schache, Blanch & Murphy 2000).
- The hamstrings originate on the Ischial Tuberosities. In the instance of anterior pelvic tilt, the Ischial Tuberosity is elevated which places the hamstrings at a greater resting length. When the hamstrings are further stretched, for example in terminal stance in the running gait, the hamstrings can exceed their maximum length. This can result in repetitive microtrauma of the hamstring muscles and increased likelihood of hamstring tears (Opar, Williams & Shield 2012).
- The skeletal system is always looking for equilibrium and efficiency- i.e. a way to stand upright with minimal amount of muscle activity and therefore energy expenditure. Anterior pelvic tilt shifts the weight of the body forwards increasing the amount of work that the postural muscles must perform to stay upright. Prolonged tension in these muscles can generate pain which is especially felt between the shoulder blades, in the thoracic and lower cervical spine. It is also common for patients with an anterior pelvic tilt to develop a thoracic kyphosis and forward head posture.
Causes of Anterior Pelvic Tilt
The musculoskeletal causes of anterior pelvic tilt have been outlined below:
- Rectus abdominis weakness.
- Poor flexibility of the hip flexors (predominately the illiopsoas).
- Increased tone and shortened length of the lower back extensors (erector spinae muscles).
- Excessive length and weakness of the hip extensors- (hamstrings).
- Inhibited, weak gluteal muscles.
First of all, it is important to recognise the deficiency that is leading to your anterior pelvic tilt. Only this will allow for effective management. I have outlined some general guidelines below, however it is important that this is used in conjunction with advice from your physiotherapist.
- Rectus Abdominis Weakness: Initially, strengthen the abdominal muscles through posterior pelvic tilt exercises. This can be progressed to crunches and prone bridging exercises. Sit-ups should be avoided as they shorten the hip flexors.
- Poor Flexibility of the Hip Flexors: This is the most common cause of anterior pelvic tilt predicated by our constant sitting in chairs which places the hip flexors at a shortened position. Stretching of these muscles is important. This can be performed in a kneeling hip flexor stretch and also through a Thomas stretch.
- Increased tone and shortened length of back extensors: Overactivity of the lower back muscles is extremely common, especially in patients who have a history of lower back pain. These patients often elect to recruit all of their back extensor muscles as a mechanism of splinting the spine so as to protect the injured area. As a result, these muscles can shorten and can actively contribute to an anterior pelvic tilt. In the following stretch- the patient is instructed to slowly pull both knees towards their chest, stretching the lower back extensors, to the point where their lower back flattens against the table.
- Excessive length of hamstrings: This is particularly relevant with Australian Rules Football players- they have hugely developed quadriceps pulling the pelvis forward, and yet, in trainings, the first muscle group stretched is their hamstrings! For these players it is usually just as simple as getting them to stop stretching their hamstrings. However, symptomatic patients may have a pathological weakness in their hamstrings. Rehabilitation should progress from concentric strengthening to eccentric strengthening exercises (for example Nordic exercises) which better represent the actual action of the hamstrings in walking and running.
- Inhibited, weak gluteal muscles: Similarly with the previously discussed common causes for anterior pelvic tilt. Inhibited gluteal muscles rarely exist without the presence of another cause- for example hip flexor tightness. Rehabilitation should begin with gluteal bridging and progress to variations of this exercise (for example- single leg bridging).
Opar, D, Williams, M & Shield, A 2012, ‘Hamstring strain injuries: factors that lead to injury and re-injury’, Sports Medicine, vol. 42, no. 3, pp. 209-226.
Schache, A, Blanch, P & Murphy, A 2000, ‘Relation of anterior pelvic tilt during running to clinical and kinematic measures of hip extension’, British Journal of Sports Medicine, vol. 34, pp. 279-283.