US 2009/0157197 A1 · BRACKET-FIXABLE RUNNING FOOT FOR LOWER LIMB PROSTHESIS

Abstract

The prosthetic foot (1) is a lamina of composite material with a characteristic J-shape, fixable by a TT bracket (2) directly to a socket (3) containing the stump, i.e. the residual part of the amputated lower limb, in the case of users with transtibial amputations, or to a TF bracket (2a) itself fixable to a mechanical knee (G) fixable to a socket (3a), in the case of users with transfemoral amputations. Said socket (3 or 3a) has a main axis (5) defined by the loading straight line by which the user, after applying the prosthesis, discharges body weight in the static position, and passing through a point (4) identifying the femoral epicondyle, real in the case of transtibial users and virtual in the case of trans femoral users, but coinciding with the centre of rotation of the knee during mid-stance. During assembly and static alignment of the foot (1), with the configuration in which the main axis (5) is in the vertical position, a segment (9) joining a first point (7) of tangency between said foot (1) and a line pertaining to a plane (6) perpendicular to the main axis (5) and defining the ground line, to a second point (8) of tangency between the foot (1) and a straight line (10) parallel to the main axis, is inclined by an angle α of between 30° and 50° to said ground line (6), said second point (8) of tangency lying at the end of a segment (11) which is inclined by an angle β of between 20° and 40° to said main axis (5) and intersects said axis at the point (4).

Claims15

Dependent claims

A prosthetic foot (1) in the form of a composite material lamina with a characteristic J-shape, fixable by a TT bracket (2) directly to a socket (3) containing the stump, i.e. the residual part of the amputated lower limb, in the case of users with transtibial amputations, or fixable by a TF bracket (2a) to a mechanical knee (G), itself fixable to a socket (3a), in the case of users with transfemoral amputations, said socket (3 or 3a) having a main axis (5) which coincides with the loading straight line during static alignment and during mid-stance, said loading straight line being that along which the user, after applying the prosthesis, discharges body weight in the static position,

the main axis (5) passing through a point (4) identifying the femoral epicondyle, real in the case of transtibial users and virtual and representative of the centre of rotation of the mechanical knee (G) during mid-stance in the case of trans femoral users,
said foot being characterised by having a morphology such that:
a segment (9) joining the point (7), representative of the 5th virtual metatarsus and being a point of tangency between said foot (1) and the ground line (6) perpendicular to the main axis (5), to the point (8), representative of the virtual heel and being a point of tangency between the foot (1) and a straight line (10) parallel to the main axis (5), is inclined by an angle α of between 30° and 50° to the ground line (6);
and in that
the point (8), representative of the virtual heel, lies along a line inclined by an angle β of between 20° and 40° to said main axis (5) and intersects the main axis at the point (4).

2 more elements

A method for positioning a prosthetic running foot (1) for a lower limb prosthesis, formed from composite material of J-shape, and connected by a TT bracket (2) to a socket (3) in the case of a user with transtibial amputation, or connected by a TF bracket (2a) to a known mechanical knee (G), itself connected to a socket (3a), in the case of a user with transfemoral amputation;

said socket (3 or 3a) having a main axis (5) which passes through a point (4) identifying the femoral epicondyle, real in the case of user with transtibial amputation and virtual and coinciding with the centre of rotation of the mechanical knee (G) during mid-stance, in the case of a user with transfemoral amputation;
in the transtibial case said method comprising the steps of:
positioning said foot (1) in proximity to the TT bracket (2) and to the socket (3) worn by the user, with provisional fixing such that the distance between the upper free end (18) of the foot (1) and the ground line (6) along an axis (10) parallel to the main axis (5) is 440±10 mm for class IV, 410±20 mm for class III, 360±30 mm for class II, and 320±10 mm for class I, and the distance D4 of the upper free end (18) of the foot (1) from the main axis (5) is 65±5 mm for class IV, 59±5 mm for class III, 53±5 mm for class II, and 49±4 mm for class I;
on the basis of this initial positioning, marking on the socket (3) the position of the TT bracket (2) such as to enable the foot (1) to be correctly positioned, then fixing the TT bracket (2) on the socket (3) with glue;
after a lamination step carried out by the orthopaedic technician on the socket (3) and TT bracket (2) such that they become a single structure, fixing the foot to the TT bracket (2) by fixing elements, for example screws;
in the transfemoral case said method comprises the steps of:
fixing the mechanical knee (G) to the socket (3a) worn by the user in an orthostatic position;
fixing the TF bracket (2a) to the mechanical knee (G) by fixing elements;
fixing the foot (1) to the TF bracket (2a) by fixing elements, such that the distance (D3) between the upper free end (18) of the foot (1) and the ground line (6) along an axis (10) parallel to the main axis (5) is 440±10 mm for class IV, 410±20 mm for class III, 360±30 mm for class II, and 320±10 mm for class I, and the distance D4 of the upper free end (18) of the foot (1) from the main axis (5) is 65±5 mm for class IV, 59±5 mm for class III, 53±5 mm for class II, and 49±4 mm for class I.

6 more elements

Dependencies are inferred from the claim text.

Bracket-fixable running foot for lower limb prosthesis

Life of this patent

Bracket-fixable running foot for lower limb prosthesis

Life of this patent

Abstract

Claims15