FPL tendon thickness, tremor and hand functions in Parkinson’s disease

INTRODUCTION: In Parkinson’s disease (PD), a resting tremor of the thumb may affect the flexor pollicis longus (FPL) and influence hand functions. We investigated the relationship between FPL tendon thickness and hand function in PD patients and compared these characteristics with those in healthy controls. METHODS: The hand grip and pinch strengths were measured. The participants completed the Duruöz hand index, the Sollerman’s hand function test, and the Nine Hole Peg Test. The thickness of the FPL tendon was measured using ultrasonography RESULTS: The FPL tendon was thicker in PD patients but was not associated with tremor severity. In PD patients, despite functional performance of the hands are impaired and grip strength is decreased, pinch strengths are preserved. FPL thickness was not correlated with grip and pinch strengths. CONCLUSION: The thicker FPL tendon may be associated with greater pinch and grip strengths and manual dexterity in healthy individuals. The presence of tremor is associated with a thicker FPL tendon.