The musculoskeletal system (MSK) forms the structural components of the body; muscles, bones, joints, and connective tissues like tendons and ligaments surrounding these structures. The musculoskeletal examination is composed of several clinical tests. Broadly, a musculoskeletal system exam could classify as a:
- Screening MS exam- a quick assessment of overall structure and function
- Comprehensive MS exam - detailed exam is typically done by rheumatologists
- Regional/focused MS exam - more specific evaluation of particular joint or other structure
Depending on the patient's chief complaint, the more appropriate musculoskeletal system exam is an option. Screening MS exam is typically a part of a complete physical examination or pre-participation physical examination of an athlete. The basic techniques of the musculoskeletal system exam are observation, palpation, and manipulation.
Observation begins with accessing any visible gross abnormalities of skin and other components of the musculoskeletal system. Palpation uses from light to firm pressure to identify and quantify the abnormalities of the musculoskeletal system, pain/tenderness, trigger points. Normal or abnormal findings that could be elicited by observation and palpation include: symmetry/asymmetry - skin color and appearance, rash, ulcers, lack of sweating hair abnormalities - warmth and heat - Swelling including effusions, nodules, and inflammatory findings like synovial and periarticular thickening - muscle atrophy, tone, contractures, and spasms - crepitations - Joint deformities including spine like kyphosis and scoliosis. Manipulation consists of different techniques to access the range of motion (ROM), strength, sensations, reflexes, and gait. The proper evaluation consists mainly of testing strength (evaluate individually the muscle capacity and integrity), range of motion (evaluate the joint independently, it's restrictions, and hypo or hypermobility), reflex and sensory function (evaluate dermatomes, reflex and sensory function, to identify possibles correlations and dysfunctions between musculoskeletal and neural system), gait analysis (evaluate the integrated functions of locomotion), and trigger points (to evaluate myofascial pain, presence of trigger points and association with patient symptoms).
Range of Motion (ROM)
ROM could be either active or passive. An active ROM is patient-initiated, which can access not only joint mobility but also an intact musculoskeletal and nervous system. Passive ROM examination is by initiating manipulation of the joint. ROM depends on the type of joint, and also it is important to know whether ROM is limited due to pain or guarding, weakness, or muscle or joint disease. Comparing to the unaffected side is indispensable. The assessment of a range of motion needs to be quantified (to avoid subjectivity bias), and for this, the use of a goniometer is indispensable. There are two types of goniometers; the first one is to use the universal goniometer and manually scale the ROM. The second is to use the smartphone goniometric application. It has indications for greater precision metrics then the universal goniometer.
To evaluate strength, the Medical Research Council scale of muscle strength (MCR-scale) is commonly used that grades the strength into 0 to 5:
- 0 – No contraction
- 1 – Flicker or trace of contraction
- 2 – Full range of active movement, with gravity eliminated
- 3 – Active movement against gravity
- 4 – Active movement against gravity and resistance
- 5 – Normal power
The bias of this scale is subjectivity depending on the experience, sensibility, and judgment of the health care professional. To avoid this bias, it is suggested to use a dynamometer. Another way to evaluate the strength in more conditioned patients is by doing the 1RM (maximum load capacity for one repetition) strength test.
Reflexes and Sensory Examination
The neuropathy impairment score (NIS) is one of the most direct scales to evaluate the correlations between the nervous system and the musculoskeletal system. It is possible to enhance the NIS by adding the dermatomal knowledge to the sensation test. It scores the reflexes and sensation (touch-pressure, pin-prick, and vibration) as:
- 0 – Normal
- 1 – Decreased
- 2 – Absent
The most important human locomotion method is gait; it provides independence and allows functionality, being the basis of daily living activities. Clinical gait analysis is the evaluation and measurement of the biomechanical walking function, the relation between the upper body and the lower body, and the dislocation of the gravity center. The gait analysis can support and enhance clinical diagnosis, decision making, and patient clinical case follow-up.
Myofascial trigger points (MTrP) are common in individuals with musculoskeletal pain. A palpable taut band characterizes the trigger point with a hypersensitive spot in the muscle. There are active and latent trigger points; the difference between them is that the active trigger point causes spontaneous and referred pain when palpated, the latent trigger point causes local, and not spontaneous pain. The evaluation of the trigger points is based on the clinical exam, but the provider can use thermography and ultrasound images to avoid clinical misinterpretations and clarify the diagnosis. The clinical palpation exam should identify the following criteria:
- Palpable taut band in skeletal muscle
- Hypersensitive tender spot within the taut band
- Reproduction of referred pain in response to MTrP compression