Inspection of the Upper Limbs
After adequate exposure, one should then lay the patient’s arms out comfortably.
The examiner should stand at the end of the bed / facing the patient if the patient is sitting, and inspect for any obvious asymmetry, wasting or abnormal posturing. If the patient is lying down, one should then stand on the right hand side of the patient and inspect the upper limbs in greater detail, focusing on whether there is any muscle wasting (proximal and / or distal muscles), fasciculations, scars and tremor. If the patient’s arms initially laid in the prone position, the examiner could then place them at the “palm-up position” and examine the ventral aspect of the upper limbs. The opposite could be done if the patient’s arms are initially laid in the “palm-up position”.
Eliciting Fasciculations of the Upper Limbs
If there are no fasciculations visible on inspection, one can tap onto the muscle bulk gently, which may bring out the fasciculations in a patient with an underlying lower motor neuron disorder. However, one common pitfall is that students often rush through tapping of the muscle bulk, but do not observe long enough for the fasciculations to appear. Often a time, the fasciculations may be visible without tapping if the muscle bulk was examined in detail (see videos of a patient with fasciculations under ‘lower motor neuron signs’).
Determining the Tone of the Upper Limbs
The tone of the upper limbs could be determined via examining the elbow and wrist joints as shown in the video. The patient’s tone should then be classified as normal, hypertonic or hypotonic. One may also be able to delineate whether the patient has lead-pipe rigidity, cogwheel rigidity (e.g. in parkinsonism), or spasticity (e.g. in patients with an upper motor neuron lesion).
Determining the Power of the Upper Limbs
The power of the upper limbs could be determined as shown in the video. One should examine the power of muscles involved in abduction and adduction of the shoulders as well as flexion and extension of the elbows, wrists and fingers. The power of the small hand muscles: finger abduction, thumb abduction and thumb opposition should then be elicited. Further detailed examination of other muscles could also be performed if the clinical history or physical examination raises clinical suspicion.
The power of the muscles should then be graded according to the Medical Research Council (MRC) scale for muscle strength as follow:
- Grade 5: Muscle contracts normally against full resistance
- Grade 4: Muscle strength is reduced but muscle contraction can still move joint against resistance
- Grade 3: Muscle strength is further reduced such that the joint can be moved only against gravity
- Grade 2: Muscle can move only if the resistance of gravity is removed
- Grade 1: Only a trace or flicker of movement is seen or felt in the muscle, or fasciculations are observed in the muscle
- Grade 0: No movement is observed
Eliciting the Upper Limb Reflexes
The reflexes of the upper limbs including the biceps, triceps and supinator reflex should be examined as shown in the video. The patient’s upper limbs should be fully relaxed. To elicit the biceps tendon reflex, roll the thumb along the biceps tendon and gently tap onto the thumb with the tendon hammer. The tendon hammer should be held towards the end and the wrist should be used to ensure a good swinging motion.
If the reflex is absent, one should proceed by performing the reinforcement maneuver (Jendrassik maneuver) by asking the patient to clench his or her teeth tightly upon tapping the tendon with the tendon hammer. The patient’s reflex should then be classified as normal, brisk (hyper-reflexic), hypo-reflexic or absent.
Testing Coordination of the Upper Limbs
A video of how rebound is elicited is also shown here.
The patient’s coordination should be assessed by the finger-nose test (to elicit intention tremor and dysmetria) and asking the patient to perform rapid alternating movements of the hand (to elicit dysdiadochokinesia).
Once again, clear, simple instructions are vital. Common pitfalls of medical students, is that during the finger-nose test, the examiner’s finger is either held too close to the patient (thus intention tremor could not be accurately assessed) or too far away. The examiner’s finger should be ideally at arm’s length from the patient. It is useful to hold onto the patient’s hand and perform the test with the patient first before asking the patient to perform it himself.