A baseball swing training apparatus including that enables a batter to determine whether his swing followed the proper principles for hitting or batting. The active component HGF has an effect to promote the proliferation of chondrocytes and to promote the production of proteoglycan. Moreover, the parking brake has elements for manually de-activating the parking brake from outside the hub. At least two final controlling devices are activated based on one single setpoint variable, and, in fact, using only one control andor regulating system associated with the intake duct.