Postural alignment refers to the relationship between body segments and in basic terms refers to the structure of the musculoskeletal system, bones, joints and muscles. The alignment of the musculoskeletal system, within normal limits, is important in terms of minimizing stresses on soft tissue, minimizing muscle effort and providing sensory information to the centres involved in motor control (the control of movement).
Hence, the musculoskeletal postural alignment plays a significant role in facilitating efficient movement during functional activities. The importance of sensory feedback to successful motor control is well established with all decisions made by the nervous system being based upon the sensory feed forward/ feedback it receives. A successful outcome is therefore reliant upon receiving sufficient accurate sensory information, a large amount of which comes from the somatosensory receptors embedded in the musculoskeletal system.
In the main, this information relates to proprioception, joint and muscle position and movement sense. Therefore it is the alignment of the musculoskeletal system which informs the nervous system of its present state for the planning of movement and also its ongoing state during movement when outcome can be monitored. The alignment of body segments is therefore critical in both posture (arrested movement) and movement itself.
The relationship between posture and movement can be viewed as integral in terms of body segment alignment with similar patterns or strategies observed in both. To appreciate any deviations from a normal range, the therapist requires knowledge of the normal parameters of posture and movement patterns and the range of normal presentations.
See Also:Berg Balance Scale
Why to assess the Postural Alignment?
A deviation from the most efficient postural alignment of the musculoskeletal system can occur as a direct effect of various neurological impairments, e.g. as a result of hypertonia, hypotonia; pain; weakness or altered sensation. The malalignment of one body segment may also produce further deviations from normal range in other segments.
For example, hypotonia involving the shoulder complex will directly result in reduced stability at the glenohumeral joint and possibly a subluxation. However, the changes in biomechanics will also immediately influence the postural alignment of both the upper limbs and the trunk as the patient finds strategies to compensate and remain balanced.
The extra effort required to move and the stresses on soft tissue may later produce pain which will further limit the biomechanics of the movement. Over time, soft tissue adaptation occurs and the new compensatory strategies become learned via the physiological processes of neuroplasticity.
Following a change in the musculoskeletal postural alignment of a body, there is a corresponding change in the somatosensory feedback to the nervous system. In the case of patients with a neurological deficit, they may be further disadvantaged by having a direct lesion involving the sensory system which may limit the amount and accuracy of the feedback.
Potentially this could lead to an inaccurate motor plan being implemented and ultimately an inefficient, unsuccessful movement. In terms of treatment, the therapist will aim to facilitate a musculoskeletal postural alignment that is within normal limits for both posture and movement.
How to assess the Postural Alignment?
As the patterns of musculoskeletal alignment are similar for posture and movement, the initial assessment can be carried out in a static posture. The assessment of postural alignment during movement is covered in the second part of the objective assessment section whereby the therapist performs a movement analysis of a functional task.
The posture chosen will vary according to the patient’s ability. For example, for a patient recently admitted with no sitting balance it will be safer in a supported sitting or supine position.
Where possible each of the main joints should be observed individually. This is necessary in order to establish the specific location of any deviation. For example, recording protraction at the shoulder complex is insufficient, as protraction involves a combination of movements at the glenohumeral joint, sternoclavicular and acromioclavicular joint and scapulothoracic joint. In order to target treatment effectively, the postural alignment of each should be evaluated.
The therapist should observe the postural alignment of all the body segments from all directions (in front, behind and from the side) taking into account all aspects of the segment orientation (anterior/posterior, superior/inferior, medial/lateral and rotation). Observing from different directions will allow the therapist to confirm the location of a deviation and its orientation/ relationship with other segments.
The therapist may gain clues related to any deviation by observing or palpating:
- Skin creases
- Bony points
- Joint lines
- Weight bearing status
- Adjacent muscle activity.
The orientation of each segment can be noted using descriptors based on the physiological movements possible at the joint. For example, when evaluating the hip joint, the descriptors available would be flexion, extension, abduction, adduction, medial and lateral rotation.
- Is the segment orientated in a neutral position?
- Is the segment symmetrical in relation to a bilateral structure (e.g. the scapulas), to a midline structure (e.g. spinous processes) and to structures above and below?
- Is the posture itself having any influence on segment alignment?
Certain postures will impose deviations and should be recorded (e.g. hip flexion in sitting) but should not influence analysis. However, if the response bilaterally is not symmetrical (e.g. left hip is externally rotated and abducted in relation to the right), then further analysis is recommended.
When recording the findings there are a few viable options to choose from. Namely:
- Body chart: Remember that when using a body chart include a key to identify the symbols used and before adding data to the chart, label left and right on each figure to avoid mistakes
- Text description.
Having completed the assessment, the therapist should have identified any deviations outside the normal limits expected. During the analysis of this data, the therapist should start to hypothesize the relationship between any deviations presented and begin to try and predict which may be causal and which may be a compensation in response. Gathering more information from the remaining objective assessment tools will be necessary before the reason for the deviations can be established.
Example For Postural Alignment Assessment
- The trunk is left side flexed, with the left side rotated forward and right side rotated backwards. The right side of the trunk appears under active.
- The right scapula is abducted, depressed and lat. rotated with under activity around the medial border. The left scapula is elevated and appears to have overactive elevators.
- Right UL has a predominance of flexor activity.
- The right side of the pelvis is rotated backwards and the right hip is abducted and externally rotated with under activity surrounding the hip.
- The patient is primarily weight bearing through the left side.
Table representation of the postural alignment assessment
|Body segment||Malalignments noted|
|Head/neck||Nil of note|
|Trunk||– Side flexion (Left)|
– rotation (Left forward)
– rotation (right backward)
right side under active
|Scapula||– right depressed/Abd/Lat rotated/Left elevated|
– right scapula under active (med border)/Left scapula over active elevators
|GH joint||Predominance of flexor over activity|
|Pelvis||right side rotated backwards|
|Hip||– right side Abd/Lat rotated|
– under active around hip
|Weight bearing||Primarily over left side|
The body chart represents patient who has suffered a right hemiplegia. Following analysis of all the objective markers and examination of the body chart the following is hypothesized. The right pelvis, hip, trunk and shoulder complex are seen to be rotated backwards probably due to hypotonia. In response, the patient works harder with the left side, especially the shoulder complex (elevation) and forward trunk rotation in an attempt to maintain an upright posture against gravity. The latter is a normal response to the deviation imposed by the hypotonia on the right. Therefore treatment would be most effective aimed at the hypotonia with the assumption that the compensatory activity would then no longer be required.
References & More Reading
- Carr JH, Shepherd RB. Enhancing physical activity and brain reorganization after stroke. Neurol Res Int. 2011;2011:515938. doi: 10.1155/2011/515938. Epub 2011 Jul 3. PMID: 21766024; PMCID: PMC3135088.
- Carr J, Shepherd R: Stroke rehabilitation guidelines for exercise and training to optimize motor skill, Edinburgh, 2003, ButterworthHeinemann.
- Kandel ER, Schwartz JH, Jessell TM: Principles of neural science, ed 4, New York, 2000, McGraw-Hill Health professions Division.
- Marrone DF: Ultrastructural plasticity associated with hippocampal learning: a meta analysis, Neurobiology of Learning and Memory 873:361–371, 2007.
- Mayston M: Handling and spasticity letter to the editor, Physiotherapy 86:559, 2000a.
- Mayston M: Compensating for CNS dysfunction letter to the editor, Physiotherapy 86:612, 2000b.
- SiliconCOACH: SiliconCOACH coaching solutions for a digital age [online]. New Zealand, 2004. www.siliconcoach.com (Accessed 1 September 2006).
- Ungerleider LG, Doyon J, Karni A: Imaging brain plasticity during motor skill learning, Neurobiology of Learning and Memory 783:553– 564, 2002.