best physiotherapist for a De Quervain tenosynovitis in chembur The role of a physiotherapist in treating De Quervain's tenosynovitis is crucial for pain relief, restoring function, and preventing recurrence. De Quervain’s tenosynovitis is an inflammation of the sheath (tenosynovium) that surrounds the tendons of the abductor pollicis longus (APL) and extensor pollicis brevis (EPB) in the first dorsal compartment of the wrist.