A differential examination is a process in which the clinician investigates, the possible presence of more conditions with similar symptoms, the patient is experiencing. The symptom of most relevance to the physical therapist is pain, however, from a physical therapy perspective, the pain mediation of primary relevance is musculoskeletal or neural. Evidently, with the advent of direct access, the physical therapist no longer has the luxury of having the medical model rule out an emergent musculoskeletal, or a systemic source of pain. The patient presenting with symptoms of pain, may in actuality have pain of a systemic origin with varying degrees of vulnerability. The varying degrees of vulnerability necessitates the physical therapist to identify clinical situations at an appropriate time, as some of the conditions may be time sensitive from a management perspective termed red flags. Appropriate identification of a red flag or a systemic source of pain may necessitate an appropriate referral and constitute the abilities of a direct access practitioner. One must clearly understand that this strategy poses no threat of infringement on the medical model. The goal of differential screening of red flags or systemic pain for the physical therapy model aims at identifying whether the presentation at hand is one that indicates physical therapy intervention, thereby:
- Avoiding a waste of time for the patient to be subjected to multiple referrals prior to availing physical therapy treatments.
- Ensuring the physical therapist that he/she is treating a condition that may necessitate physical therapy intervention or a cross referral to the appropriate practitioner.
- From a corporate perspective, minimizing the need for healthcare funds to be unnecessarily utilized for multiple referrals.
- Most importantly, inculcating a sense of responsibility in the physical therapist to continually improve practice competency.
Typically most texts on medical screening for physical therapists begin with a systems review. A systems review may be appropriate dependent on the luxury of time and expertise available to do so. A systems review usually begins with the systemic system and relates it to the symptom. The physical therapist may require first hand knowledge of ‘what system to review that is most relevant to the symptom?’ If structured with adequately available time, this may be an appropriate method to adopt.2
However, a consult to musculoskeletal physical therapy is usually trauma, disease, or pain arising from a gradual degenerative, non-traumatic onset that may be very region specific like, shoulder pain, back pain, knee pain, neck pain, etc. The initial thought process that may address a region specific source of pain, maybe more appropriate. Physical therapy curriculums provide adequate information as to the musculoskeletal sources of regional pain, however, an additional quick screen of the possible systemic sources of regional pain may help institute an appropriate referral, when necessary.
Physical therapists are traditionally taught to think neuromusculoskeletal, for obvious reasons, as they are practitioners treating neuromusculoskeletal dysfunction. It may be erroneous, however, to assume that an individual seeking the services of a physical therapy practitioner has neuromusculoskeletal concerns. Hence, practice patterns have evolved to make the physical therapist sensitive to issues outside of the musculoskeletal system, however lacking structure. At a basic level, they comprise musculoskeletal red flags, which are trauma related or systemic red flags, where malignancy has occupied the priority list. This model may well work, when the patient as a practice pattern is routinely referred by the medical model. However, this may be inadequate, when the patient seeks the services of a physical therapist without prior consultation with the medical practitioner. The need then may be two fold:
- To first think outside of the musculoskeletal system.
- To have a structure in evaluating sources of pain outside of the musculoskeletal system.
Most conditions that are appropriate for physical therapy intervention have either a traumatic or degenerative etiology. It is obvious that pain may be a predominant symptom in both situations. However, pain does manifest regionally without the presence of trauma and degeneration. Table 1.1 suggests1 such sources that the physical therapy model should routinely consider in the evaluation process.
The need is obvious. As mentioned earlier, with the advent of direct access of consumers to physical therapy services, the physical therapist no longer has the luxury of assuming the pain presentation to be musculoskeletal.
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The consequences can be detrimental, when the clinical judgment of the first contact practitioner does not meet the needs of the patient. However, if the clinician is capable of making such a judgment, an appropriate referral can be executed, resulting in a practice pattern complementary to that of the medical model.2 Therefore, when a patient seeks physical therapy services with regional pain issues the ‘first stage’ of the thought process should ideally not be musculoskeletal (unless one suspects a musculoskeletal red flag right away, e.g. fracture, tendon rupture, etc.). The following is a pattern suggested.
Stage One (May Require Emergent or Appropriate Referral to the Medical Model)
- Musculoskeletal red flags
- Systemic mediation (including systemic red flags)
- Yellow flags (non-organic sources of pain for personal gain or psychogenic issues).
Strategies for the Physical Therapist
The process consists of:
- Having a knowledge base of neurovascular and musculoskeletal red flags.
- Having a knowledge base of systemic red flags and systemic mediation to the regional pain.
- History, clinical signs, symptoms and special tests for interpretation of the above. Special tests may include screening laboratory tests and radiographs. Additionally, observing the personal dynamics and social history to see, if the patient presents with non-organic sources for the pain for personal gain or psychogenic issues.
Stage Two (Where the Patient is Deemed Appropriate for Physical Therapy)
- Musculoskeletal mediation/lesion diagnosis.
- Physical therapy/somatic diagnosis.
Strategies for the Physical Therapist
- Having a knowledge base of conditions that cause a specific regional pain.
- History, clinical signs, symptoms and special tests for interpretation of the above.
- Radiology and imaging.
- Differentiating it to a somatic diagnosis.
Stage Three (Not Addressed in this Literature Review)
Principles of Stage One
The intent in stage one is to not arrive at an accurate medical diagnosis. The intention is to only determine appropriateness of the patient for physical therapy intervention. Assume a female patient sought an orthopedic consult for pelvic pain and the orthopedician on evaluation fails to identify a distinct musculoskeletal pattern, but evidently on history taking identifies changes in urinary frequency, dysuria (pain on urination) and bouts of chills and fever, the most likely plan of action may lean towards a gynecological referral or back to primary care. Physical therapists in a direct access capacity, may assume a similar role. To establish adequate competency, identify signs and symptoms that may not lean towards a musculoskeletal origin of symptoms, the clinician should be able:
- To first think outside of the musculoskeletal system.
- To have a structure in evaluating sources of pain, outside of the musculoskeletal system.
- Subsequently continue with routine examination of the musculoskeletal system, once the appropriateness for physical therapy intervention has been established.
No pain has more relevance to the physical therapist than muscle and joint pain. When consumer awareness increases with regards to direct access to physical therapy, muscle pain/myalgia may be a common symptom encountered. Traditional training may automatically tune the physical therapist to think musculoskeletal. With the evolution of high standards musculoskeletal evaluation and treatment from a physical therapy perspective, this attitude has doubled in vigor as we are now looking at musculoskeletal lesions, different from the medical model from a cause rather than a symptom perspective and making us unique in our approach. As a first contact practitioner, however, the mind set has to change, maybe permanently, better yet in the infancy of physical therapy curriculums. As an example, muscle and joint pain should lead the physical therapist to think as follows (Table 1.2) before concluding the origin of pain to be musculoskeletal.
The table indicates the need for change in the mode of thinking during patient examination. It is a brief overall review, however, the presentation may be region specific. In which case this evaluation structure should be applied from a regional perspective. The aim of this literature review is to structure such an evaluation process from a regional perspective to foster a change in the thought process during examination.
Examination of non-organic sources of pain as in psychogenic and psycho-somatic issues is an elaborate topic and beyond the scope of this book. However, the clinician is suggested to be aware of the potential presence of this factor. A work injury, a motor vehicle accident undergoing legal proceedings, an abused spouse, recent divorce, sexual abuse, etc. present as painful situations for possible secondary gains, or may be a true mental illness. The clinician should avail the necessary resources to address such a situation, when encountered.5
Principles of Stage Two
Lesion and Somatic Diagnosis
The ‘lesion’ in the context of this literature review will signify all conventional diagnosis of musculoskeletal disorders. Hence, a ‘lesion diagnosis’ will be the musculoskeletal diagnosis that a physical therapist and other faculties as in orthopedics, physical medicine and primary care, will understand. For example, rotator cuff syndrome is common to all of the above mentioned faculties, but the ‘somatic’ cause for a rotator cuff syndrome as in a ‘downward scapula’ or a ‘superomedial humerus’ is unique to the physical therapist because it is a diagnosis of the cause of the lesion, rotator cuff syndrome. Hence, the two types of diagnosis are addressed individually, however, the correlation of how the somatic diagnosis has lead to the lesion will be enumerated. The somatic diagnosis typically involves detection of alignment deviation of landmarks or unilateral weakness and tightness of soft tissue, restricted joint or tissue mobility, and tenderness locally.36
Taking rotator cuff impingement as an example, the ‘lesion diagnosis’ involves an individual that comes to you with complaints of pain in the shoulder that is aggravated by overhead activity with difficulty sleeping. While this patient has no stage one issues, based on your clinical knowledge database, you suspect that this individual probably has a rotator cuff impingement. You are establishing a pre-test probability. Now the examination procedure that involves positive findings on palpation for tenderness of the long head of biceps and supraspinnatus, and special tests as in a Neer impingement test or a Hawkins kennedy test will further strengthen your pretest probability. These positive findings establish the ‘lesion’ which is rotator cuff syndrome. Now, how are you going to treat this condition. A fact often reinforced is that these are dysfunctions and not diseases. A dysfunction always has a mechanical cause and identifying the faulty mechanics will constitute the ‘somatic diagnosis’. A somatic dysfunction, as mentioned earlier will almost always have an alignment deviation of landmarks, unilateral weakness and tightness of soft tissue, restricted joint or tissue mobility and tenderness locally. The shoulder, being a ball and socket joint can be an example. During abduction, the head of the humeral glides inferiorly and externally rotates on the glenoid. When this occurs, the space between the greater tuberosity and the acromion is adequate, and the supraspinatus tendon is not impinged. If a restriction prevails, then the inferior glide of the humeral head decreases and the greater tuberosity may pinch the tendon against the acromion as it rides up on forceful abduction. If the thoracic segments are restricted in flexion, it can disturb the mechanics of the trapezius and the rhomboids, which in turn attach to the scapula resulting in a protracted and downwardly rotated scapula. A resulting protracted scapula or rounded shoulders may disturb the scapulohumeral rhythm, bring the acromion closer to the greater tuberosity causing an impingement of the tendon between it. Routine local injections or medication may provide symptomatic relief, but to obtain a more functional outcome, the inferior glide of the humeral head has to be restored, backward bending of the thoracic segments has to be achieved, efficiency of the trapezius, rhomboids and shoulder rotators has to be restored, then the cause for the problem is addressed. Your ‘somatic diagnosis’ will be a flexed rotated side bent thoracic segment, or a decreased inferior and posterior glide of the humeral head, or a downward protracted scapula and a weak lower trapezius. This results in an impingement and supraspinatus tendonitis. Hence, the factors identified in the somatic diagnosis is what you will treat with manual therapy, modalities, appropriate exercise prescription and activity modification.
REFERENCES
- Collins D. Differential Diagnosis in Primary Care. Lippincott Williams & Wilkins. Philadelphia, PA; 2003.
- Delitto A, Erhard RE, Bowling RW, et al. A treatment-based classification approach to low back syndrome: identifying and staging patients for conservative treatment. Phys Ther. 1995;75(6):470–85; discussion 485–9.
- Sebastian D. Principles of Manual Therapy, 2nd edition. 2013, Jaypee Brothers Medical Publishers (P) Ltd: New Delhi; 2013.