A mobile apparatus that is automated to measure controlled and applied forces and moments to sport surfaces allowing for performance and safety assessment of athletic apparel and athletic surfaces, such as natural or artificial turf. The apparatus is capable of using not only shear and compressive forces, but also rotational moments, and all prescribed forces and moments in combination at the same or different times. The apparatus and related system can link these forces and moments together and combine them to more closely mimic behaviors of a human foot during an athletic movement, thereby applying and measuring interactions between all forces and moments at the same or different times.

A mobile apparatus that is automated to measure controlled and applied forces to sport surfaces allowing for safety assessment of athletic apparel and athletic surfaces, such as natural or artificial turf. The apparatus is capable of using not only horizontal and vertical forces, but also rotational moments, and all prescribed forces and moments in combination at the same or different times. The apparatus and related system can apply horizontal and vertical forces, and rotational moments, and link these forces and moments together and combine them to more closely mimic behavior of human foot during an athletic movement, thereby applying and measuring interactions between all forces and moments at the same or different times.

A system assesses activity and displays a unitless activity value. A detector senses activity of a user. A processor reads sensed activity data from the detector. A display displays the unitless activity value. An enclosure houses the detector and the processor. The processor periodically reads the sensed activity data from the detector and processes the data to generate an activity number, the number being used to generate the unitless activity value based upon a maximum number and a display range.

A mobile apparatus that is automated to measure controlled and applied forces to sport surfaces allowing for safety assessment of athletic apparel and athletic surfaces, such as natural or artificial turf. The apparatus is capable of using not only horizontal and vertical forces, but also rotational moments, and all prescribed forces and moments in combination at the same or different times. The apparatus and related system can apply horizontal and vertical forces, and rotational moments, and link these forces and moments together and combine them to more closely mimic behavior of human foot during an athletic movement, thereby applying and measuring interactions between all forces and moments at the same or different times.

Provided is a system for measuring rigidity characteristics that measures a CT value of a golf club head based on an acceleration occurring in an impactor when the impactor is caused to strike the golf club head. Correlation data is calculated by measuring a representative CT value of the golf club head, which is calculated based on CT values measured multiple times by changing the impact velocity of the impactor, and a test velocity CT value, which is a CT value when the impact velocity is set to a predetermined test velocity, for each of a plurality of the golf club heads of an identical model. A rigidity characteristic value measuring device measures the test velocity CT value for another golf club head of the model. A computer estimates the representative CT value of the other golf club head based on the test velocity CT value and the correlation data.

Provided is a rigidity characteristics measuring device that measures the rigidity characteristics of a golf club head. A head fixing jig holds the golf club head with a face surface facing upward. A linear bushing causes an impact rod to drop vertically toward the golf club head. The impact rod is equipped with an acceleration sensor. A computer calculates the rigidity characteristics, e.g., a CT value, of the golf club head, based on a detected value of the acceleration sensor.

A restitution coefficient measuring device measuring a restitution coefficient of a measuring object includes a holder that holds a spherical impact ball colliding with the measuring object with an elastic member, a shooting mechanism for shooting the impact ball held by the holder from the holder toward the measuring object, a speed measuring unit that measures both a collision speed at which the impact ball collides with the measuring object and a restitution speed at which the impact ball bounces from the measuring object, and a computing unit that calculates the restitution coefficient on the basis of the restitution speed with respect to the collision speed. A hole for bleeding air is bored on any side surface of the holder. The elastic member is an independent member replaceable with respect to the holder and is disposed at an end portion of the holder in an axial direction.

A method and system for determining concentricity of a multiple layer golf ball are disclosed herein. One or more images of a golf ball are generated using an X-ray source, a camera or a digital detector, and an image intensifier. An edge detection algorithm is preferably utilized. The method also includes calculating Y,Z center coordinates of the a best fit diameter or ellipse of the inner edge layer and outer edge layer of the multiple layer golf ball.

An apparatus to measure swing mass moments of sports' implements includes an apparatus that receive a handle of a sports' implement and measures rotational angularity thereof using a calibrated counter force element and using a static mode of measurement in association with a scale having a plurality of readings.

A portable device for determining whether a tennis ball is compliant with a stated deformation standard compresses a tennis ball by application of a pre-determined pre-load followed by a pre-determined force. A scale is provided for measuring the deformation of the tennis ball after it is compressed. The device includes several plate members disposed in parallel and relatively movable a controllable amount by a shifting mechanism.