A golf swing analysis apparatus detects a state of a shaft of a golf club by using an output from an inertial sensor, calculates a relative rotation angle of the shaft which changes about an axis of the shaft until the shaft transitions from a first state to a second state due to a swing of the shaft, and compares the calculated relative rotation angle with a reference relative rotation angle in a reference swing which is used as a reference, with respect to at least one of a change range of the relative rotation angle, the required time from the first state to a state in which the relative rotation angle becomes the maximum, and the maximum value of the relative rotation angle, and outputs a comparison result.

Methods for determining performance information for an object located within an area include obtaining magnetic field information for the area, measuring first magnetic field data when the object is located at a first position within the area, and determining performance information for the object within the area based on the magnetic field information for the area and the first magnetic field data.

In a first aspect, a system for monitoring a swing is provided that includes (1) a swing measurement device adapted to couple to a swinging object and to output a signal indicative of a characteristic of the swinging object; (2) a wireless transmitter coupled to the swing measurement device and adapted to wirelessly transmit the signal output by the swing measurement device; and (3) a wireless device adapted to receive the wirelessly transmitted signal and to provide information regarding the swinging object based on the received signal. The wireless device is a cellular telephone or personal digital assistant (PDA). Numerous other aspects are provided.

A shaft for a golf club includes a first end, a second end, and a demarcation. The first end is adapted to attach to a club head. The second end is adapted to receive a grip distal to the first end. The demarcation is positioned at or adjacent to the balance point of the golf club between the first end and the second end.

Golf club components with complex such as lattice structures, beam structures, and complex surface-based structures, are described herein. A binder jet machine is used create complex structures within these golf club components to optimize weighting, sound, and performance of golf club heads. These components may be manufactured using a method that preferably includes the steps of designing a golf club head component in CAD using optimization software, printing the component from a powdered material, and then removing excess powder from the component via port holes that extend into an external surface of the component and communicate with interior voids within the component.

A virtual play system is composed of a mobile terminal 2 worn by a player P, a virtual play display terminal 6 provided with a display unit 86, and a cloud server 4 capable of communicating with the mobile terminal 2 and the virtual play display terminal 6. The mobile terminal 2 includes a data analysis unit that transmits first measurement data obtained by measuring and quantifying an actual motion of player P during play and second measurement data obtained by measuring and quantifying the motion of player P during simulated play to the cloud server 4, and the cloud server 4 includes a virtual play data generation unit that calculates virtual play data based on the first measurement data and the second measurement data, and the virtual play display terminal 6 displays the virtual play data.

Some disclosed golf club heads include body having at least one raised sole portion and a cantilevered ledge extending down around a perimeter of the club head below the level of the raised sole portion. Some disclosed golf club heads include one or more sole openings in the body and a sole insert that is mounted inside the body over the sole openings. The sole can include weight tracks as well, and a rear weight track can extend between a toe side sole opening and a heel side sole opening. A crown insert can also be included that is mounted over an upper opening in the body.

Audio systems and methods for obtaining location information are disclosed. A portable, wireless speaker that may include a beacon that a user may activate to remotely trigger a request for shot information, which may include location information of the user or speaker. The beacon may be wirelessly coupled to the speaker. The speaker may receive location information from a remote device, such as a GPS-enabled mobile phone. The shot information may be converted into an audio format for playback by the speaker. The speaker may pause the playback of the speaker to play out the shot information.

A system and method for analyzing and improving the performance of a body motion of an animal or human subject requires instrumenting a subject with inertial sensors, monitoring a body motion of interest, converting sensor data into motion data and animation, comparing the motion data with existing data for motion related performance parameters, providing a real-time, information rich, animation and data display of the results in color coded displays; and based on the results prescribing a training regime with exercises selected from a library of standardized exercises using standardized tools and training aids.

A golf swing teaching device to interpret a golf swing comprising a golf club, where the golf club includes a handle, a shaft and a head; a laser attached to the golf club, where the laser directs a beam parallel to the shaft of the golf club; a reflective indicator mat, where the reflective indicator mat extends between a first end and a second end; a rest toward the first end, where the rest positions a golf ball on the reflective indicator mat; an ideal swing line along a central portion of the reflective indicator mat, where the ideal swing line extends from the first end to the second end; and a plurality of sensors along the reflective indicator mat, where the plurality of sensors detect a path of the beam over the reflective indicator mat and deviation of the beam from the ideal swing line.