背景：隨著時代科技的進步以及生活水準的提升，使得現代人在身體活動的機會逐漸減少，運動是增進健康最快的途徑，而登階運動為時下熱門的有氧運動之一；登階運動除了心肺功能上的促進，下肢的運動學表現也是值得去注意的。目的：本研究目的為比較在不同的聽覺刺激下進行登階運動時，膝關節的角度變化以及膝部肌肉用力的情形，同時也想比較男女在登階運動表現的差異。方法：研究者收取十位男性與十位女性分別進行三種情境之登階運動：1.沒有聽覺刺激下進行登階運動2.聆聽有氧舞蹈音樂下進行登階運動3.聆聽新聞廣播下進行登階運動，進行時分別測量表皮肌電圖及利用三度空間攝影系統量取膝關節角度。結果：女性受試者在無聽覺刺激之情境下，股內側肌的活化程度大於兩種雙重作業情境(p=0.019)；男女在無聽覺刺激情境下，右側膕內側腱肌的活化程度明顯大於有氧音樂情境(p=0.032)；而在有氧音樂情境下，膝關節彎曲角度明顯小於無聽覺刺激以及聽新聞情境下的膝關節角度(p=0.041)。結論：不同的聽覺刺激可能改變膝關節肌肉的活化程度與運動學。此外，不同聽覺刺激下，男女的運動學表現也不同。要注意的是，在聽新聞的情況下從事登階運動，可能較易對女性造成分心甚至出現膝關節不穩定的情形。

Bench stepping is one popular aerobic exercise for young adults. The benefits of bench stepping on cardiopulmonary function have been reported previously. Aerobic exercise is always performed with music. However, whether this kind of background auditory stimulation will affect the kinematics and kinetics of lower extremities for bench stepping is not clear. The purpose of this study was to compare the kinematics and muscle activities of lower extremities for bench stepping in three different test conditions. Methods: Twenty subjects were recruited for this study. They were asked to perform bench stepping exercise in three different conditions: simple bench stepping (single), bench stepping while listening to the aerobic exercise music (dual 1), and stepping while listening to radio news (dual 2). Surface EMG were attached on vastus medialis and medial hamstring. Twenty one markers were attached on bilateral lower extremities in order to capture the kinematic data of the lower extremities. Results: Women decreased the muscle activity on bilateral vastus medialis under both dual task conditions (p=0.019). All subjects had lower muscle activity on right medial hamstring for the aerobic music condition as compared to single task condition (p=0.032). Besides, they also had a smaller knee flexion range for the aerobic music condition as compared to the single task and news condition (p=0.041). Conclusion: Different auditory stimulation may affect the muscle control pattern as well as knee kinematics. Besides, the strategy for male and female exercises to perform dual task bench stepping was different. Our results demonstrated that women may split their attention easily during bench stepping while listening to news report. It may lead to increase instability of the knee during bench stepping.