Abstract: A golf practice device is disclosed to derive a proper stance and swing form of a golf club. The device to be installed on a shaft of a golf club with a club head, comprises a fixing part to be installed on the shaft and including a bearing part formed at a part thereof, and a shaft part to be fitted in the bearing part. In a state where a longitudinal direction of the shaft is horizontalized and a toe side of the club head is located on a ground side, the fixing part is installed at a center of gravity position of the entire golf club, on the shaft, and one end in an opposite side of the bearing part in the longitudinal direction, of the shaft part faces a vertical direction with respect to the longitudinal direction of the shaft to point a core of the golf club.

Abstract: Golf putting training devices are disclosed that include a body portion and a shaft attachment piece. The shaft attachment piece is connected to the body portion and is configured to attach the golf putting training device to a shaft of a putter. The golf putting training devices further include a shaft indicator surface, which is configured to rest adjacent to and along the shaft of the putter. In addition, the golf putting training devices include a sight alignment shield, which is connected to the body portion and is configured to be positioned perpendicular to the shaft indicator surface.

Abstract: Methods and systems for detecting configuration states of a golf club and adjustment systems of a golf club, such as a shaft connection system. A golf club configuration detection system captures configuration data from the adjustment system of the golf club by a configuration detection device, such as a camera, a barcode scanner, or an RFID scanner. The captured configuration data is compared to reference configuration data to determine a configuration state of the adjustment system. Swing data and ball-flight data are tracked for golf-ball strikes with the golf club in the detected configuration state. Recommendations for configuration states may be generated based on the tracked data.

Abstract: A pendulum stroke teaching device formed from a one piece coupling element for use with conventional golf alignment sticks and an individual's putter club. The coupling element includes two spaced apart apertures for receipt of the distal ends of the alignment sticks. A centrally disposed cavity between the apertures is constructed and arranged for receipt of a putter shaft. The coupling element operates to secure the alignment sticks and putter in a fixed position. The ends of the alignment sticks are placed between the torso and the inner upper arms of the golfer. When the golfer grasps the putter grip, movement of the putter can only take place by use of a pendulum stroke. The teaching device is used for training the golfer to use a repetitive and consistent swing for improving their golf experience.

Abstract: A golf putter has a hollow shaft that has a longitudinal channel, a grip that surrounds a portion of the shaft, a putter head, and an adjustable counter-balance weight system. The weight system has a rod that has a four-sided configuration and at least one weight. Each weight has an annular weight housing that has a four-sided channel extending longitudinally therethrough, and with each weight housing having a threaded opening. The rod extends through the channel of the weight housing of the at least one weight, and a threaded setting screw is threaded through the threaded opening and impinges on one of the four sides of the rod to secure the weight inside the four-sided channel.

Abstract: Some embodiments include club heads having reinforced club head faces. Other embodiments of related club heads and methods are also disclosed.

Abstract: A golf training club has a shaft having a proximal end and a distal end. The shaft defines a longitudinal axis. A club head is coupled to the distal end, the club head having a sole, a club face, and an upper surface. An address alignment gauge extends along the longitudinal axis of the shaft. The club face defines a closed face angle about the longitudinal axis of the shaft with respect to the address alignment gauge that is between about 20 degrees and about 40 degrees. A lie angle between the shaft and ground surface is between about 55 and 75 degrees.

Abstract: A golf putter has a hollow shaft that has a longitudinal channel, a grip that surrounds a portion of the shaft, a putter head, and an adjustable counter-balance weight system. The weight system has a rod that has a four-sided configuration and at least one weight. Each weight has an annular weight housing that has a four-sided channel extending longitudinally therethrough, and with each weight housing having a threaded opening. The rod extends through the channel of the weight housing of the at least one weight, and a threaded setting screw is threaded through the threaded opening and impinges on one of the four sides of the rod to secure the weight inside the four-sided channel.

Abstract: A method comprising, in a striking face of a golf club head, the striking face being formed of a first material having a first hardness, creating a plurality of initial grooves, the initial grooves having a first cross-sectional area (A1) and a first pitch (P1) such that A1/P1>0.0030 in. The method continues with modifying the initial grooves at least by positioning a second material in each of the plurality of initial grooves, the second material having a second hardness that is less than the first hardness, such that the first material and the second material form a plurality of final grooves each having a second cross-sectional area (A2) and a second pitch (P2) such that A2/P2<0.0030 in.

Abstract: A putter head comprising a novel alignment structure is disclosed herein. In particular, the putter comprises an alignment sphere attached to an upper surface of a lower flange and an alignment ring suspended over the lower flange and vertically aligned with the alignment sphere. When a golfer has oriented the putter properly in front of a golf ball at address, the alignment sphere will appear to the golfer to be encircled by the alignment ring.

Abstract: Golf practice devices are adapted to facilitate practicing without obstructing a putting surface or practice area. According to one example, a golf practice device can include a first base member with a first clamping end and a first handle end, and a second base member with a second clamping end and a second handle end. A portion of the first base member located between the first clamping end and the first handle end may be hingedly coupled to a portion of the second base member located between the second clamping end and the second handle. At least one coupling arm may be pivotably mounted to the first base member, and an attachment feature may be coupled to the first coupling arm. In some examples, a sight or a cell phone with an integrated camera may be coupled to the attachment feature. Other aspects, embodiments, and features are also included.

Abstract: A ball striking device, such as a golf club, includes a head with a face having a striking surface configured for striking a ball and being defined by a plurality of peripheral edges, a body connected to the face and extending rearwardly from the peripheral edges of the face, and a sole member connected to the sole of the body. The sole member may be removably connected to the sole, which can permit removal and replacement with another sole member having a different property. The sole member may additionally or alternately be movably connected to the sole, which can permit adjustment of the sole member, such as to change the lie angle of the head. The sole member may be at least partially received in a receiver in the sole and may form at least a portion of the lowermost surface of the head.

Abstract: A golf club with a golf club head having non-metallic fasteners is presented. The club head may include a face member, a body member, a sole member and a crown member. The various portions of the club head may be connected using mechanical fasteners, such as screws. In some arrangements, the screws may be formed of a non-metallic material, such as a composite material, in order to reduce weight associated with the club head. In some arrangements, a portion of the mechanical fasteners may be formed of a non-metallic material and may be placed in regions of the club head where reduced weight is desired, while another portion of the fasteners may be formed of metal or other heavier material and may be placed in regions where additional weight may be desired.

Abstract: A visual reference and feedback device for use with a golf club is presented. The visual reference and feedback device includes a clubface reference head and a neck that connects a supporting body to the clubface reference head. The supporting body includes three supporting members having a first supporting member, a second supporting member, and a third supporting member. C-clip fasteners may be formed at distal ends of the first supporting member and second supporting member. A sternum guide may be formed as a rectangular structure at the outer portion of the first supporting member and proximate to the neck of the visual aid and feedback device.

Abstract: A golf club (2) comprising a shaft (20), a head and a damping device (1, 100). The damping device (1, 100) includes an anchor element (3, 103) and a damping element (4, 104) interconnected by a rigid rod (5, 105). The anchor element (3, 103) is anchored within the lower section of the shaft (20) that has a substantially constant diameter such that the damping element (4, 104) is in contact with an internal surface of the shaft (20) to dampen vibrations therein.

Abstract: Some embodiments include a golf club. The golf club includes a golf club head body having a face surface arranged for impacting a golf ball, a rear surface opposite the face surface, a sole surface, a crown surface including a first crown surface and a second crown surface, and a toe surface including a first toe surface and a second toe surface. The toe surface transitions to the crown surface at a toe end curved boundary surface comprising a first curved boundary surface where the first toe surface transitions to the first crown surface, a second curved boundary surface where the second toe surface transitions to the second crown surface, and a toe end radius of curvature. At least part of the toe end radius of curvature varies. Other embodiments of related golf clubs and methods are also disclosed.

Abstract: A ball striking device, such as a golf club, includes a head with a face having the ball striking surface located at a front of the head and a plurality of parallel face grooves extending laterally across at least a portion of the ball striking surface, a body connected to the face and extending rearward from the face, and an indicator on the ball striking surface of the face. The indicator is located in an area between the face grooves and proximate a lateral center of the ball striking surface, and includes at least one indent in the ball striking surface. The indent has a depth that is substantially less than a depth of any of the face grooves. Methods associated with such ball striking devices are also provided.

Abstract: When hitting a ball to a target with a putter, the ball often travels to a point which is deviated to the right from the target. When a golfer looks at the target just after taking his address, he turns his head to a target about a rotation axis which extends through the back of his head. When this rotation axis is not horizontal and an angle defined by the rotation axis and his sighting line to a putter head is not 90°, he has an optical illusion which tricks him into believing that he has to correct his address position. The putter of the present invention is provided with a thin-plate pendulum thereby allowing him to turn his head about the rotation axis while keeping the angle defined by the rotation axis and his sighting line at 90°.

Abstract: A putt break visualization instrument useful for improving putting includes an elongated object such as a crossbar that extends from the shaft of a putter and is normal thereto. The golfer begins by addressing the golf ball. The golfer then holds the putter above the green by the handle in the manner of a plumb line so that the shaft of the putter is vertically oriented and the crossbar is horizontally oriented. The golfer then aligns the shaft with the uphill edge of the golf ball, and moves the shaft up or down along the vertical so that the crossbar extends in proximity to the cup. The golfer may use a slider on the crossbar to mark the cup. The golfer may now evaluate how well he or she has addressed the golf ball, and either repeat the process if improvement is needed or make the putt.

Abstract: A golf club head having an adjustable hosel and a level is disclosed herein. The adjustable hosel is movable between a plurality of positions to adjust at least one feature of the golf club head, such as loft, lie, and/or face angle, and is held in place by an adjustment knob or adjustment lever. The level preferably is a bubble level that is disposed proximate a scale to indicate to a golfer an optimal loft, lie, and/or face angle of the golf club head.

Abstract: The combination set of tools comprising a slope reading tool and rotary clip head and angle plate is designed to build putting confidence and shave strokes off every golfer's game. The slope reading tool is a high accuracy “bubble level” device that provides actual slope angle around the golf cup to give golfer a quick and accurate reading of the green's contours. The set of rotary clip head and angle plate which is attached to the putter shaft can be rotated to the angle indicated on the slope reading tool to make the adjustment to achieve a more accurate putting. This combination set is intended to help golfers on putts with subtle or confusing breaks and works best on putts within 12 feet of the hole.

Abstract: A golf putting training device is configured for attachment to a golf putter for use during practice sections. The putting training device includes aiming rods configured to be mounted on the putter so the rods are perpendicular to the ball striking surface of the putter.

Abstract: Attachable systems and methods allow a golfer to ‘zero in’ on the desired striking zone or “sweet spot” of a club, including putters and non-putters. One or more guides are positionable relative to the desired striking zone, such that if a golf ball interacts with a guide during a swing, the guide provides aural or tactile feedback that the club has hit the ball outside of the desired striking zone. The device may include at least two guides, one positionable on one side of the desired striking zone and the other positionable on the other side of the desired striking zone. The device may comprise guides in the form of a tab or leaf pivotable from an up position when not in use to a down position for use. If the club head has a back side, a portion of the device may contact with the back side.

Abstract: A golf club swing training apparatus and a method for fabricating it are provided. The apparatus includes a golf club shaft and a slide mechanism. The shaft includes an upper portion and a lower portion that are spaced apart to form a gap there-between. The slide mechanism is inserted within this gap and is connected to the lower end of the upper shaft portion and the upper end of the lower shaft portion. The slide mechanism includes an upper connector, a sliding rail, a rail guide block, and a lower connector that are configured to permit a lateral shift of this lower portion relative to this upper portion during a swinging of the club. The method uses an axial alignment apparatus to maintain the elongated axis of the upper shaft portion in substantial alignment with the elongated axis of the lower shaft portion when the slide mechanism is being connected.

Abstract: Golf club heads include white diffusing top surfaces to aid in club head alignment. Wood type club heads also include a dark diffusing club face so that a crown/face border is emphasized. Scorelines in wood type clubs can be provided with an intermediate contrast surface, and can be displaced from club face center to accommodate player perception when confronted with a white diffusing crown. Putter heads can include dark diffusing alignment lines, and iron-type club heads can include white diffusing surfaces at a sole portion of a club face, at a top line, or a top portion of a club face.

Abstract: A putt break visualization instrument useful for improving putting includes an elongated object such as a crossbar that extends from the shaft of a putter and is normal thereto. The golfer begins by addressing the golf ball. The golfer then holds the putter above the green by the handle in the manner of a plumb line so that the shaft of the putter is vertically oriented and the crossbar is horizontally oriented. The golfer then aligns the shaft with the uphill edge of the golf ball and moves the shaft up or down along the vertical so that the crossbar extends in proximity to the cup. The golfer may use a slider on the crossbar to mark the cup. The golfer may now evaluate how well he or she has addressed the golf ball, and either repeat the process if improvement is needed or make the putt.

Abstract: A golf club head in which a top surface of the body includes an actual top surface visible profile region and a varied top surface visible profile region is provided. The varied top surface visible profile region may provide a visual impression of a varied profile of the body distinct from an actual profile of the body. The visual impression is oriented in a manner that allows the golfer to address the ball at the heel region of the golf club. The perimeter of the top surface visible profile region may be complementary in shape to the perimeter of the top surface of the body and the varied top surface visible profile region and the actual top surface visible profile region may be distinct in shape, size, color, and/or finish etc. An associated golf club and a method for fitting a golf club are also provided.

Abstract: A golf club aiming sight device having a clamp portion and a rear sight portion. The rear sight portion has one or more openings to visualize a front sight on a club head of a golf club. The clamp portion provides for the attachment of the golf club aiming sight device to the shaft of the golf club so that the front sight is visually alignable with the opening in the rear sight. The golf club aiming sight device is used to train a user to swing the golf club without bending or rotating the wrists by having the user maintain the front sight visually aligned with the opening in the rear sight while swinging the golf club.

Abstract: A golf club head is provided and includes a club head body, a club head face connected to a front portion of the club head body, wherein the club head face includes a club face surface having a plurality of face cavities arranged across the club face surface and a plurality of protrusion posts, wherein each of the plurality of protrusion posts includes a post body having a post base and a post head, wherein the plurality of protrusion posts is associated with the club face to extend away from the club face surface such that the post base of each of the plurality posts is located in separate cavities of the plurality of face cavities.

Abstract: A wood-type club head can include a front end having a front face, a toe end, a heel end opposite the toe end, a rear end opposite the front end, a crown surface having a front crown end and a rear crown end, and an alignment aid at the crown surface. The front crown end can be closer to the front end than to the rear end, and the rear crown end can be closer to the rear end than to the front end. The alignment aid can include three alignment aid stripes. The three alignment aid stripes can include a toe alignment aid stripe, a heel alignment aid stripe, and a center alignment aid stripe. Other embodiments are also disclosed.

Abstract: A method relating to an improved fitting system for a golf club shaft is disclosed herein. More specifically, the present invention utilizes specific data gathered from the golfer's golf swing itself to determine the best performing golf club shaft for this particular golf swing. Even more specifically, the present invention relates to the utilization of infrared motion capturing cameras to record the location data of a golf club shaft throughout a swing. Based on the location data captured, one or more dynamic behavioral characteristics can be calculated to determine one or more preferred shaft characteristics. Using the preferred shaft characteristics, a shaft can be recommended for the golfer having this particular golf swing. The current inventive fitting methodology is preferred to the archaic fitting method of using data gathered from the result orientated ball flight data together with a tedious process of having to try numerous different shafts.

Abstract: Systems, methods, and computer readable media for changing and controlling settings for adjustable golf clubs are described. Such setting adjustment systems may alter one or more of: lie angle, loft angle, face angle, shaft stiffness, shaft kickpoint location, weighting, weight positioning, face flexibility, maximum face flex location, etc. These systems and methods may use various types of information to determine the appropriate settings, such as: ball launch monitor data, swing path data, weather input data, course condition input data for a location of play, course design input data for a location of play, daily course layout input data for a location and a time of play, golfer past performance data (e.g., recent past performance, past performances at the location of play, past performance during an ongoing round of golf (i.e., on earlier played holes), etc.), current adjustable club setting information, and information indicating holes to be played.

Abstract: A golf club having at least one directional based graphic on the golf club it disclosed. More specifically, the golf club in accordance with the present invention will have at least one directional based graphic that will only be visible when the golf club is oriented in a desirable direction while staying invisible in all other undesirable directions.

Abstract: A golf swing instructional device for training a golfer comprises an attachment portion having a first portion adapted to be positioned at the shaft of a golf club and a second portion adapted to be connected to two guide supporting elements. The first and second supporting elements have each a contact surface to be in contact with one or the other forearm of the practicing golfer. The two supporting elements are extending from the club contacting portion, wherein the first portion comprises a reception to accommodate the shaft of a golf club and fixation means to fix the first portion around the shaft of the club. The two guide supporting elements each comprise a first straight portion, a second straight portion and a bent connecting portion in-between.

Abstract: A system and method for calibration of golf shots is provided. Specifically, a tool for providing a reference target superimposed over an image of the cup for calibration purposes is provided. An optical putter calibration tool may include a viewing area and a reference target image. The reference target image may be manufactured within the viewing area or removably affixed to the exterior of the viewing area. The viewing area may be integrated in a shaft of a golf club, such as a putter, for providing a simultaneous view of the cup and the reference target image. Comparison of the reference target image and the view of the cup may provide a determination of a playing surface characteristic.

Abstract: A golf club head with a body and an asymmetrical visual swing indicator is provided. The asymmetrical visual swing indicator may be formed to represent an apparent backswing path outward of an actual backswing path. In certain configurations the asymmetrical visual swing indicator is positioned such that a portion of the asymmetrical visual swing indicator closest to the hitting surface of the golf club is closer to a heel end plane of the golf club head then a portion of the asymmetrical visual swing indicator closest to a rear surface of the golf club head. The swing indicator is integral with the body of the golf club head.

Abstract: A golf aid including a yoke portion with a pair of the divergent upper portions, a pair of forearm guide portions, one associated with each of the divergent upper portions of the yoke and a resilient means to bias the forearm guide portions into an extended condition whereby a user's forearms apply force to the forearm guide portions against the biasing force in order to maintain optimum spacing between the user's forearms.

Abstract: A golf club having at least one directional based graphic on the golf club it disclosed. More specifically, the golf club in accordance with the present invention will have at least one directional based graphic that will only be visible when the golf club is oriented in a desirable direction while staying invisible in all other undesirable directions.

Abstract: The invention generally relates to a setting indicator for a golf club having an adjustable attribute. The invention provides a component to serve as a setting indicator or setting display device for a golf club or a golf club having a setting indicator. The setting indicator includes a window and an adjustment mechanism configured to provide a golf club with a selected attribute while also displaying an indicia through the window to provide information about the selected attribute.

Abstract: Systems, methods, and computer readable media for changing and controlling settings for adjustable golf clubs are described. Such setting adjustment systems may alter one or more of: lie angle, loft angle, face angle, shaft stiffness, shaft kickpoint location, weighting, weight positioning, face flexibility, maximum face flex location, etc. These systems and methods may use various types of information to determine the appropriate settings, such as: ball launch monitor data, swing path data, weather input data, course condition input data for a location of play, course design input data for a location of play, daily course layout input data for a location and a time of play, golfer past performance data (e.g., recent past performance, past performances at the location of play, past performance during an ongoing round of golf (i.e., on earlier played holes), etc.), current adjustable club setting information, and information indicating specific holes to be played.

Abstract: A club head can include a front end having a front face, a toe end, a heel end opposite the toe end, a rear end opposite the front face, a crown surface having a front crown end and a rear crown end, and an alignment aid at the crown surface that extends between the front crown end and the rear crown end. The club head can be a wood-type club head. Meanwhile, the front crown end can be closer to the front end than to the rear end, and the rear crown end can be closer to the rear end than to the front end. The alignment aid can have an alignment aid width approximately equal to a golf ball diameter and can include two or more alignment aid stripes.

Abstract: A driver club head can include a front end having a front face, a toe end, a heel end opposite the toe end, a rear end opposite the front end, a crown surface having a front crown end and a rear crown end, and an alignment aid at the crown surface. The front crown end can be closer to the front end than to the rear end, and the rear crown end can be closer to the rear end than to the front end. The alignment aid can include two or more alignment aid stripes. The two or more alignment aid stripes can include a first alignment aid stripe and a second alignment aid stripe extending between the front crown end and the rear crown end. Other embodiments are also disclosed.

Abstract: A putter site orienting device and method that linearly aligns a putter having a shaft longitudinal axis, a gripping portion, a putting head, a golf ball having indicia marked thereon, and target golf hole including a putter shaft attaching portion having a contoured face that attaches to the shaft; a magnet integrally formed with the shaft attaching portion that magnetically secures device to the shaft; a rigid rod having a longitudinal axis and a diameter Dr substantially smaller then a diameter Dp of the shaft integrally formed with the shaft attaching portion including a first end integrally formed with the shaft attaching portion, and second free end opposite the first end wherein the rigid rod protrudes outwardly and perpendicularly from the shaft attaching portion to allow proper alignment of a putter to which the device attaches with respect to both a golf ball and to a target golf hole.

Abstract: A golf club head in which a top surface of the body includes an actual top surface visible profile region and a varied top surface visible profile region is provided. The varied top surface visible profile region may provide a visual impression of a varied profile of the body distinct from an actual profile of the body. The visual impression is oriented in a manner that allows the golfer to address the ball at the heel region of the golf club. The perimeter of the top surface visible profile region may be complementary in shape to the perimeter of the top surface of the body and the varied top surface visible profile region and the actual top surface visible profile region may be distinct in shape, size, color, and/or finish etc. An associated golf club and a method for fitting a golf club are also provided.

Abstract: Attachable systems and methods allow a golfer to ‘zero in’ on the desired striking zone or “sweet spot” of a club, including putters and non-putters. One or more guides are positionable relative to the desired striking zone, such that if a golf ball interacts with a guide during a swing, the guide provides aural or tactile feedback that the club has hit the ball outside of the desired striking zone. The device may include at least two guides, one positionable on one side of the desired striking zone and the other positionable on the other side of the desired striking zone. The device may comprise guides in the form of a tab or leaf pivotable from an up position when not in use to a down position for use. If the club head has a back side, a portion of the device may contact with the back side. In particular, if the club is an iron with a rear cavity on the club head, a portion of the device may be received in the cavity to enhance stability, particularly during a swing. Training methods are also disclosed.

Abstract: A golf club head with a body and an asymmetrical visual swing indicator is provided. The asymmetrical visual swing indicator may be formed to represent an apparent backswing path outward of an actual backswing path. In certain configurations the asymmetrical visual swing indicator is positioned such that a portion of the asymmetrical visual swing indicator closest to the hitting surface of the golf club is closer to a heel end plane of the golf club head then a portion of the asymmetrical visual swing indicator closest to a rear surface of the golf club head. A method of fitting a golf club head by determining an initial swing plane using a measuring device, determining a desired swing plane, and applying an asymmetrically shaped visual indicator to a golf club head based upon the determined initial swing plane and the desired swing is also provided.

Abstract: A putt break visualization instrument useful for improving putting includes an elongated object such as a crossbar that extends from the shaft of a putter and is normal thereto. The golfer begins by addressing the golf ball. The golfer then holds the putter above the green by the handle in the manner of a plumb line so that the shaft of the putter is vertically oriented and the crossbar is horizontally oriented. The golfer then aligns the shaft with the uphill edge of the golf ball and moves the shaft up or down along the vertical so that the crossbar extends in proximity to the cup. The golfer may use a slider on the crossbar to mark the cup. The golfer may now evaluate how well he or she has addressed the golf ball, and either repeat the process if improvement is needed or make the putt.

Abstract: A golf club shaft selection device includes: a plurality of synthetic resin or metallic tube members which are adapted to be wound individually around a plurality of areas of a golf club shaft which result when the golf club shaft is so divided along the length thereof, wherein one or two tube members in the plurality of tube members are fixed around the shaft so as to change a stiffness value and kick point of the shaft at the areas around which the tube members are wound.

Abstract: The present invention relates to a golf club having alignment markings that assist a golfer in finding a proper and consistent posture before addressing the ball. In one embodiment, a golf club according to the present invention includes a shaft, a club head having a striking face, a hosel coupling the club head to the shaft, and one or more alignment markings at a position substantially elevated from the club head and substantially behind the shaft. Embodiments of the golf club may further comprise an appendage extending outwardly from the golf club and carrying alignment markings thereon in a direction substantially parallel to the striking face. Such alignment markings provide a golfer with a proper setup when the shaft is seen by the golfer as interposed between, and parallel to, the alignment markings. A golf club according to the present invention may be configured in a variety of shapes, for example, as a putter, an iron, a driver or a wood.

Abstract: A golf aid including a yoke portion with a pair of the divergent upper portions, a pair of forearm guide portions, one associated with each of the divergent upper portions of the yoke and a resilient means to bias the forearm guide portions into an extended condition whereby a user's forearms apply force to the forearm guide portions against the biasing force in order to maintain optimum spacing between the user's forearms.