Devices systems and methods are disclosed. Among other things, the devices systems and methods can facilitate ergonomic gripping of a handle; conform to the shape of a wrist; enhance golf techniques or performance; enhance racket sport technique or performance; protect a head of a user engaged in contact sports or other hazardous activities; identify concussions, in some cases in substantially real time; provide sterilization of garments; control surgical robots; allow for medical treatment of multiple subjects without disrobing; provide biometric or other data; and/or be used to train muscles or body parts for, for example, performing specified tasks using a body part.

A face of a racket includes a plurality of first longitudinal threads, a plurality of second longitudinal threads, and a plurality of transverse threads. The first longitudinal threads and the second longitudinal threads are arranged alternately from a center of the face toward outside in a width direction of the racket. A material of each first longitudinal thread is different from a material of each second longitudinal thread. A tension of the first longitudinal thread may be different from a tension of the second longitudinal thread. Preferably, a ratio (N1/N2) of a number N1 of the first longitudinal threads to a number N2 of the second longitudinal threads is greater than or equal to 2/8, but less than or equal to 8/2.

Devices systems and methods are disclosed. Among other things, the devices systems and methods can facilitate ergonomic gripping of a handle; conform to the shape of a wrist; enhance golf techniques or performance; enhance racket sport technique or performance; protect a head of a user engaged in contact sports or other hazardous activities; identify concussions, in some cases in substantially real time; provide sterilization of garments; control surgical robots; allow for medical treatment of multiple subjects without disrobing; provide biometric or other data; and/or be used to train muscles or body parts for, for example, performing specified tasks using a body part.

Devices systems and methods are disclosed. Among other things, the devices systems and methods can facilitate ergonomic gripping of a handle; conform to the shape of a wrist; enhance golf techniques or performance; enhance racket sport technique or performance; protect a head of a user engaged in contact sports or other hazardous activities; identify concussions, in some cases in substantially real time; provide sterilization of garments; control surgical robots; allow for medical treatment of multiple subjects without disrobing; provide biometric or other data; and/or be used to train muscles or body parts for, for example, performing specified tasks using a body part.

Devices systems and methods are disclosed. Among other things, the devices systems and methods can facilitate ergonomic gripping of a handle; conform to the shape of a wrist; enhance golf techniques or performance; enhance racket sport technique or performance; protect a head of a user engaged in contact sports or other hazardous activities; identify concussions, in some cases in substantially real time; provide sterilization of garments; control surgical robots; allow for medical treatment of multiple subjects without disrobing; provide biometric or other data; and/or be used to train muscles or body parts for, for example, performing specified tasks using a body part.

A set of racket cross-string guides which are pre-woven over a string guide holder in the same pattern used for inserting the racket cross-strings.

Devices systems and methods are disclosed. Among other things, the devices systems and methods can facilitate ergonomic gripping of a handle; conform to the shape of a wrist; enhance golf techniques or performance; enhance racket sport technique or performance; protect a head of a user engaged in contact sports or other hazardous activities; identify concussions, in some cases in substantially real time; provide sterilization of garments; control surgical robots; allow for medical treatment of multiple subjects without disrobing; provide biometric or other data; and/or be used to train muscles or body parts for, for example, performing specified tasks using a body part.

A face of a tennis racket includes a plain weave structure including a plurality of longitudinal threads, a plurality of high-tension transverse threads 36, and a plurality of low-tension transverse threads 38. The tennis racket includes a spin facilitating zone 46. The spin facilitating zone 46 includes: (1) a first high-tension transverse thread 36; (2) a second high-tension transverse thread 36; and (3) an odd number of low-tension transverse threads 38 positioned between the first high-tension transverse thread 36 and the second high-tension transverse thread 36. The spin facilitating zone includes no other high-tension transverse thread 36 positioned between the first high-tension transverse thread 36 and the second high-tension transverse thread 36.