We display a virtual avatar changing its biceps appearance to fit the user's biceps contraction. The avatar's biceps changes its size and color based on either: (EMG) the biceps activity (recorded with a electromyography [EMG] sensor); or (ANG) the elbow angle; or (EMG + ANG) the biceps activity and elbow angle. The users also wear an ad hoc haptic device around their biceps to give the illusion of stronger biceps contractions. In the Virtual Environment, the participants (N=10) look at their right biceps and do elbow flexion. They rate EMG, ANG and EMG + ANG (with and without the haptic device) along Body Ownership and Agency. We found that ANG (without the haptic device) was rated noticeably lower on the Agency than EMG and EMG + ANG (both without the haptic device). It is likely better to change the appearance of a muscle using the user's muscle contraction rather than the user's movement when considering the user's muscle ownership and agency. The addition of the ad hoc haptic device appeared to not affect the Sense of Embodiment.