A system has footwear and a striking device. The striking device has a shaft connected to a striking surface for contacting an object. A sensor affixed to the shaft changes electrical resistance when the striking surface is swung to contact the object to in turn generate a signal reflective of the deflection of the shaft. The footwear is configured with an array of sensors that change at least one electrical characteristic upon deflection when the player is operating the striking device. The footwear is to send signals reflective of the deflection of the feet as the shaft is swung. The signals reflective of the deflection of the shaft and the footwear are sent to a cell phone, notebook, PC or the like suitably programmed to present audio and visual images of the feet positions and movement and movement of the striking device (e.g., golf club, racket).

A system for fitting golf clubs to golfers that enables an overall club length to be varied without varying a length of a shaft. The system enables a greater number of combinations of club characteristics, such as shaft flex, brand, and length, to be contained within a club fitting cart and/or for a same number of combinations of club characteristics to be contained within a smaller cart.

A lightweight sweet spot trainer includes a sleeve that is slipped over the barrel end of any bat. The sleeve covers the barrel over the primary contact area of the bat. The sleeve holds a force sensor placed inside it such that, when slid over the bat, the force sensor is coincident with the sweet spot of the bat. When a ball comes in contact with the sweet spot, the force sensor directly beneath it is triggered such that instantaneous feedback is given to the athlete thereby making him/her aware of accurate sweet spot contact. Moreover, an array of cylindrical contact/force sensors can be positioned such that the user gets feedback that would depend on how far from the sweet spot the user strikes/contacts the ball. The user may be notified by audio, visual, or sensory cues.

An apparatus for engagement with a barrel of a bat includes a cup and at least one cover. The cup is secured for securement to a distal end of the barrel of the bat. The cup defines a cavity and includes a first connector portion. The at least one cover has a second connector portion cooperating with the first connector portion to releasably secure the cover to the cup over the cavity.

A tennis racket fitting method according to the present invention comprises: a first step of preparing a plurality of test tennis rackets, at least one type of racket property that influences swing for hitting a ball being defined for each of the test tennis rackets; a second step of causing a reference tennis racket to be swung at least one time by a user in order to hit a tennis ball, and acquiring a measured value by measuring transition in at least one of the position, the velocity, the acceleration, and the angular velocity of the reference tennis racket in at least a portion of an interval from when the swing starts until when the swing ends; a third step of calculating at least one evaluation indicator to be an evaluation of the swing of the reference tennis racket based on the measured value; and a fourth step of, based on the racket property, selecting a tennis racket that can improve at least one evaluation indicator from among the test tennis rackets.

A ball striking device, such as a golf club, includes a head with a face having a ball-striking surface configured for striking a ball, a body connected to the face, and at least one channel in the ball-striking surface of the face. The region of highest COR response of the face is directionally enlarged toward the channel. Depending on the size, shape, and location of the channel, the face can be altered to provide greater COR response and increased energy transfer for impacts at specific locations on the face.

A manner of manufacturing a modernized nunchuck using specifically adjusted workings or saw process construction methods, facilitating a better fit and functions for the nunchuck, while increasing levels of safety and precision operations for users. The nunchuck includes a first and second grip handle, having a top and bottom end. The top ends machined with a quarter rounded edge to minimize resistance against movement. A single cord configuration includes a flexible coupling having alike end accommodated and fixed in place by a coupling anchor and anchor support at top end of first and second grip handles. Anchor support also functions as a handle grip guide assisting precise and consistent hand placement during use of the saw nunchuck. Each bottom end comprises an optical stripe, providing a variety of light reflections for improved ocular functions and visual effects enhancing user performance.

A ball striking device, such as a golf club, includes a head with a face having a ball-striking surface configured for striking a ball, a body connected to the face, and at least one channel in the ball-striking surface of the face. The region of highest COR response of the face is directionally enlarged toward the channel. Depending on the size, shape, and location of the channel, the face can be altered to provide greater COR response and increased energy transfer for impacts at specific locations on the face.

An apparatus for a ball bat and a ball bat comprising at least one disc member that defines an outer diameter corresponding to an inner diameter defined by the ball bat to create a fit within close proximity between the at least one disc member and the ball bat. The at least one disc member can be located within the barrel portion of the ball bat. The at least one disc member can include at least one solid disc member that is located within a sweet spot of the ball bat. In some embodiments, the apparatus for a ball bat and the ball bat can further include an at least one insulation foam member. The at least one insulation foam member can separate the at least one disc member. The at least one insulation foam member can define a hollow center portion.

A handle grip control device configured to be removably secured to a handle of an instrument includes a body having a first outer surface and an inner surface, and a protrusion extending radially outwardly from a respective proximal end at the first outer surface of the body to a distal tip. The inner surface defines a cavity configured to receive handles of instruments, and the protrusion can define a second outer surface that includes a first and second sloped surfaces opposite to a bottom surface. A slope of the first sloped surface defines a first angle relative to a plane that is perpendicular to a longitudinal axis of the body, and a slope of the second sloped surface defines a second angle relative to the plane that is greater than the first angle.