Wheelchair for specialized sports applications

A wheelchair comprising:

• a frame comprising an upper portion and a lower portion that is coupled to the upper portion so that the upper portion is vertically adjustable with respect to the lower portion, wherein the upper portion of the frame is angularly adjustable with respect to the lower portion of the frame at a selectable anterior-to-posterior tilt;
• a pair of drive wheels coupled to the lower portion of the frame;
• and
• a plurality of casters coupled to the lower portion of the frame.

A wheelchair comprising:

• a frame;
• a pair of drive wheels coupled to the frame;
• and
• a plurality of casters coupled to the frame, wherein each caster has a respective swivel axis, wherein at least one caster of the plurality of casters is configured to be locked to prevent swiveling about its respective swivel axis and unlocked to enable swiveling about its respective swivel axis,
• wherein the at least one caster of the plurality of casters comprises:
• a fixed portion and a swivel portion that is selectively pivotable with respect to the fixed portion about the respective swivel axis, wherein the fixed portion and the swivel portion each define at least one spline;
• and
• a locking collar that is slidable along the swivel axis between a first position and a second position, wherein the locking collar defines an internal groove that is configured to receive therein a respective spline of the at least one spline of the fixed portion and a respective spline of the at least one spline of the swivel portion, wherein, when the at least one spline of the swivel portion of the at least one caster is aligned with the internal groove of the locking collar, the locking collar is configured to move from the first position to the second position, wherein, in the second position, the locking collar is configured to inhibit pivoting of the swivel portion of the at least one caster with respect to the fixed portion of the at least one caster.