Joint range of motion does vary widely within the general population because of differences in age, joint laxity, and individual anatomy. Furthermore, active and passive ranges frequently differ with range increased on passive movement. The American Society for Surgery of the Hand (ASSH) offers a guide to normal joint ranges, which is worth reviewing (Table 71.1).1 All of the ranges described in the clinical scenario are reduced for a healthy 35-year-old male, with the exception of answer option A. The MCP joints have a large range of motion, both passive and active. This also differs between the digits, with most being present in the little finger which can commonly have 40 degrees of extension and 90 degrees of flexion. Range of motion progressively decreases in the MCP joints moving radially from the little finger to index. This is in contrast to the PIP joint which normally has a range of 0 to 100 degrees only because of the box ligamentous structure and it is more consistent between the digits. It is vital to have a good understanding of normal and abnormal joint ranges when assessing hand patients in clinic. The best approach is to compare left with right in most cases, as this helps ascertain the “normal” or baseline range for each individual. Joint ranges must be documented in the notes, especially in conditions such as Dupuytren’s disease or following a hand injury. Table 71.1 Normal Range of Motion Reference Values for the Upper Limb Typical Range of Motion (Degrees) Elbow Extension/flexion 0/145 Forearm Pronation/supination 70/85 Wrist Extension/flexion 70/75 Radial/ulnar 20/35 Thumb basal joint Palmar adduction/abduction Radial adduction/abduction Contact or 45 Contact or 60 Thumb interphalangeal (IP) joint Hyperextension/flexion 15/80 Thumb metacarpophalangeal (MCP) joint Hyperextension/flexion 10/55 Finger distal interphalangeal (DIP) joint Extension/flexion 0/80 Finger proximal interphalangeal (PIP) joint Extension/flexion 0/100 Finger MCP joint Hyperextension/flexion (0–45/90)
To assess the AdP, a paper sheet is placed between the thumb and index finger, and the patient is asked to forcibly grasp it against resistance (Fig. 71.1). Flexion at the thumb IP joint can occur to compensate when AdP is weak (positive Froment’s test, which is a classic test for ulnar nerve function). The flexor digitorum profundus (FDP) is assessed by immobilizing the digit and testing for isolated distal interphalangeal (DIP) joint flexion. Assessment of the flexor digitorum superficialis (FDS) requires that the adjacent digits are held in extension while flexion of the proximal interphalangeal (PIP) joint is attempted (Figs. 71.2 and 71.3). Immobilization is required to prevent the FDP from contributing to PIP joint flexion as it also crosses the A B Fig. 71.1 Froment’s sign. Test is positive in six (compensatory flexion at interphalangeal [IP] joint). (Adapted from American Society for Surgery of the Hand. The Hand: Examination and Diagnosis, 3rd ed. Philadelphia: Churchill Livingstone, 1990.) Fig. 71.2 Test for FDP myotendinous function. (Adapted from American Society for Surgery of the Hand. The Hand: Examination and Diagnosis, 3rd ed. Philadelphia: Churchill Livingstone, 1990.) Fig. 71.3 Test for flexor digitorum superficialis (FDS) myotendinous function. (Adapted from American Society for Surgery of the Hand. The Hand: Examination and Diagnosis, 3rd ed. Philadelphia: Churchill Livingstone, 1990.) joint. The flexor pollicis longus (FPL) is assessed by active flexion of the IP joint, not the MCP joint, which is flexed by the thenar muscles abductor pollicis brevis (APB), opponens pollicis, and flexor pollicis brevis (Figs. 71.4 and 71.5). The APB is tested with the hand placed on a table and the palm facing upward not downward (Fig. 71.6). The assessment of APB is a classic test for the recurrent motor branch of the median nerve at the wrist.1–3
3. Tubiana R, Thomine J, Mackin E. Examination of the Hand and Wrist. 1st ed. London: CRC Press; 1998 correct? joints in flexion. EDC function is assessed by asking the patient to extend the fingers at the knuckles (MCP joint) with IP joints flexed or asking them to straighten all fingers simultaneously. To independently assess the extensor indicis proprius (EIP) and extensor digiti minimi/extensor digiti quinti (EDM/EDQ), the respective digits should be extended independently (Fig. 71.7). Isolated active extension at the thumb IP joint does not specifically test for integrity of the EPL tendon, because the extensor pollicis brevis (EPB) can also cross this joint and be responsible for IP joint extension. The EPB insertion is highly variable: it is absent in around 5% of hands, inserts into the MCP joint extensor hood in around 25%, into the base of the proximal phalanx in around 25%, and continues right up to the distal phalanx in 25%.1 Therefore, to accurately assess EPL function, the patient should be asked to put their hand flat on a surface and lift their thumb up off that surface. The full length of the EPL tendon from the extensor retinaculum to IP joint will usually be seen and be palpable (Fig. 71.8). Extensor carpi radialis longus (ECRL) and extensor carpi radialis brevis (ECRB) share the same action but can be independently assessed by palpation while asking the patient to make a fist and extend the wrist (see Fig. 71.8). Abductor pollicis longus (APL) and EPB are tested with the same movement but may also be differentiated by palpation of the tendons. The patient should be instructed to move their thumb out to the side or do a thumbs-up gesture (see Fig. 71.7). Extensor carpi ulnaris (ECU) is best tested by having the patient extend the wrist with ulnar deviation while palpating the tendon at the wrist (see Fig. 71.11).2–4
Patients with de Quervain’s tenosynovitis have tenderness and swelling affecting the first extensor compartment. Pain is exacerbated by stretching the tendons passing within this compartment, namely APL and EPB. This can be tested with either Finkelstein’s test or Eichhoff’s test. Both involve stretching of the tendon by pulling the hand into Fig. 71.7 Test for extensor digitorum communis (EDC), extensor indicis proprius (EIP), and extensor digiti minimi (EDM) (extensor digiti quinti [EDQ]) myotendinous function. (Adapted from American Society for Surgery of the Hand. The Hand: Examination and Diagnosis, 3rd ed. Philadelphia: Churchill Livingstone, 1990.) Fig. 71.8 Test for extensor pollicis longus (EPL) myotendinous function. (Adapted from American Society for Surgery of the Hand. The Hand: Examination and Diagnosis, 3rd ed. Philadelphia: Churchill Livingstone, 1990.) ulnar deviation and applying traction on the thumb. Although the test can be performed with the thumb clasped within the patient’s own fingers, it is generally thought to generate more false-positive results than placement of traction on the relaxed thumb (Fig. 71.9). There may also be discomfort during other movements, such as thumb extension where APL and EPB may be active, but ulnar deviation of the wrist is usually the most painful.1–3
A positive Tinel’s sign is indicated by a tingling sensation along the course of a nerve when it is tapped at the site of compression or regeneration. It is a useful method to assess nerve regeneration in cases such as two-stage facial reanimation techniques and following upper limb nerve injury. As nerve compression increases, progressive axonal loss can lead to a loss of Tinel’s sign in more severe cases, but there is no proportional change relating to greater damage. Although Tinel’s sign is used as part of a clinical examination for carpal tunnel syndrome and nerve regeneration, the results are variable and examiner dependent. Therefore, this test is not diagnostic or reliable in isolation and should be combined with other information.1–3
Sparing of the dorsal sensory branch of the ulnar nerve suggests pathology distal to this branch, which arises 5 to 7 cm proximal to the ulnar styloid. More proximal lesions, or a diffuse neuropathy, would usually affect all the distal functions of the nerve, both motor and sensory.1–3
This patient has objectively normal findings despite his subjective complaints. Although a degree of reduced sensation is reported, a significant digital nerve injury is very unlikely, with the normal two-point discrimination displayed (normal values for two-point discrimination are static, up to 6 mm in the fingertip, and dynamic 2 to 3 A B Fig. 71.9 A, Finkelstein’s test for de Quervain’s tenosynovitis. B, Eichhoff’s test for de Quervain’s tenosynovitis. mm). Six weeks is too early for normal two-point discrimination to return after a complete or 50% nerve injury. Moist skin suggests preserved sweating and wrinkling on immersion also suggests a largely intact digital nerve. Sweating is very useful to assess when suspecting digital nerve injury, as where a patient describes altered sensation distal to a laceration and the finger also feels smooth over the same distribution, division of the nerve is likely.1–3
This patient has most likely had a compression of the superficial radial nerve at the wrist from the handcuffs, resulting in a neurapraxia rather than a complete nerve division. The lateral antebrachial cutaneous nerve territory does not extend onto the hand. The posterior interosseous nerve has mainly motor function with the exception of sensory supply to the dorsal wrist capsule. A proximal radial nerve injury would involve motor weakness with decreased extension and wrist drop.1–2