WO2017205396A1

WO2017205396A1 - Device for measuring range of motion of ankle

Info

Publication number: WO2017205396A1
Application number: PCT/US2017/034033
Authority: WO
Inventors: Mohsen ABASSI
Original assignee: 32905.09 Patent Application Trust
Priority date: 2016-05-23
Filing date: 2017-05-23
Publication date: 2017-11-30

Abstract

The device for measuring range of motion of an ankle (10) provides for angular measurement of the range of motion of a patient's ankle, and includes a foot rest (12) having a base (14), a pair of sidewalls (16, 18) and an inclined upper surface (20). A foot retainer (22) releasably receives the patient's foot (F). A mounting plate (24) is slidably mounted to one of the pair of sidewalls (16, 18). The lower end (36) of an elongated rod (32) is rotatably mounted to the mounting plate (24). An inclinometer (42) is secured to the elongated rod (32). A retaining bar (44) is secured to the elongated rod (32), adjacent its upper end (34). The retaining bar (44) is adapted for positioning adjacent a calf muscle (C) of the patient when the patient's foot (F) is received in the foot retainer (22).

Description

DEVICE FOR MEASURING RANGE OF MOTION OF ANKLE

TECHNICAL FIELD

The present invention relates to measurement of range of motion of a patient' s ankle, and particularly to a device for measuring range of motion of an ankle for both side-to- side movement (i.e., eversion and inversion) and vertical foot movement (i.e., dorsiflexion and plantar flexion).

BACKGROUND ART

The ankle includes three joints, namely the ankle joint proper or talocrural joint, the subtalar joint, and the inferior tibiofibular joint. The full range of motion (ROM) of a person's foot about the ankle is defined by the range of motion of each of these three joints, particularly side-to-side foot motion (i.e., eversion and inversion) and vertical foot motion (i.e., dorsiflexion and plantar flexion). In order to diagnose angle injury, most measurements of ankle range of motion are only taken in an up and down direction (i.e., vertical angular movement). Only measuring dorsiflexion and plantar flexion is equivalent to leaving at least half of potentially valuable data unmeasured. Thus, a device for measuring range of motion of an ankle solving the aforementioned problems is desired.

DISCLOSURE OF INVENTION

The device for measuring range of motion of an ankle provides for angular measurement of the range of motion of a patient's ankle. The device for measuring range of motion of an ankle includes a foot rest having a base, a pair of sidewalls and an inclined upper surface. A foot retainer is secured to the inclined upper surface of the foot rest for releasably receiving the patient' s foot. The foot retainer is preferably rotatably secured to the inclined upper surface. A mounting plate is slidably mounted to one of the pair of sidewalls, such that the mounting plate is selectively slidable along a direction parallel to the inclined upper surface for proper positioning with respect to the patient' s foot and ankle. It should be understood that the mounting plate may be slidably mounted to the foot rest in any suitable manner, such as, for example, by a pair of brackets secured to the foot rest for slidably receiving the mounting plate.

An elongated rod, having opposed upper and lower ends, is further provided, with the lower end thereof being rotatably mounted to the mounting plate. An inclinometer, such as a digital inclinometer, angle sensor or the like, is secured to the elongated rod for measuring an angular displacement of the elongated rod with respect to the inclined upper surface of the foot rest. A measuring member may be further fixedly secured to the mounting plate. The measuring member has indicia formed thereon indicating an angular displacement of the elongated rod, such that the elongated rod and the measuring member form a conventional goniometer. It should be understood that the inclinometer performs the measurement of the patient' s range of motion, and the goniometer may be used for calibrating the inclinometer.

A retaining bar is secured to the elongated rod, adjacent the upper end thereof, with the retaining bar extending substantially orthogonal to the elongated rod. The retaining bar is adapted for positioning adjacent a leg of the patient when the patient's foot is received in the foot retainer. Preferably, the retaining bar is slidably mounted on the elongated rod for selectively adjusting a height of the retaining bar with respect to the foot rest, allowing the device for measuring range of motion of an ankle to be used by patients having varying heights and body types.

These and other features of the present invention will become readily apparent upon further review of the following specification and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a perspective view of a device for measuring range of motion of an ankle according to the present invention.

Fig. 2 is a perspective view of the device for measuring range of motion of an ankle according to the present invention in a first configuration.

Fig. 3 is a perspective view of the device for measuring range of motion of an ankle shown in an alternative configuration.

Similar reference characters denote corresponding features consistently throughout the attached drawings.

BEST MODES FOR CARRYING OUT THE INVENTION

The device for measuring range of motion of an ankle 10 provides for angular measurement of the range of motion of a patient's ankle. As shown in Figs. 1 and 2, the device for measuring range of motion of an ankle 10 includes a foot rest 12 having a base 14, a pair of sidewalls 16, 18 and an inclined upper surface 20. In conventional devices for measuring range of motion (ROM) of a patient's ankle, only the angular movement in an up and down direction is measured (i.e., vertical angular movement). The inclined upper surface 20 of the foot rest 12 allows the patient to position his or her foot F at a horizontal angle, allowing for measurement of side-to-side (i.e., eversion and inversion) and vertical range of motion (i.e., dorsiflexion and plantar flexion). In other words, the device for measuring range of motion of an ankle 10 allows for measurement of a full functional range of motion of the ankle, which includes contributions from both the subtalar joint, also known as the talocalcaneal joint, and the talocrural joint. It should be understood that the overall contouring and relative dimensions of foot rest 12 are shown for exemplary purposes only. The inclined upper surface 20 is inclined at approximately 40° with respect to base 14, which is adapted for sitting on a support surface, such as a horizontal floor surface.

A foot retainer 22 is secured to the inclined upper surface 20 of the foot rest 12 for releasably receiving the patient' s foot F. The foot retainer 22 is preferably rotatably secured to the inclined upper surface 20 to allow the foot rest to be rotated 360°. However, the foot retainer 22 can be detachably secured to the foot rest 12 to permit repositioning of the foot retainer 22 in this manner. The foot retainer 22 can be positioned for measuring a side or horizontal bending movement of the ankle joint, as illustrated in Fig. 2 or for measuring a vertical bending movement of the ankle joint, as illustrated in Fig. 3. The foot retainer 22 includes a pad 50 or contoured mount for comfortably supporting the sole of the patient's foot F. At least one strap 46 may be provided for releasably securing the patient' s foot F during measurement. It should be understood that any suitable type of pad or retainer may be used in the construction of foot retainer 22, and that straps 46 are shown for exemplary purposes only, and foot F may be secured to foot retainer 22 by any suitable releasable fixture or fastener.

A mounting plate 24 is slidably mounted to one of the pair of sidewalls. In the example of Figs. 1-3, the mounting plate 24 is shown slidably mounted to sidewall 16, although it should be understood that mounting plate 24 could be slidably mounted to sidewall 18 with the device for measuring range of motion of an ankle 10 operating in a substantially identical manner. As shown, the mounting plate 24 is selectively slidable along a direction parallel to the inclined upper surface 20 for proper positioning with respect to the patient' s foot and ankle. Mounting plate 24 may be selectively held in a desired position by tightening knob 52, or through the usage of any suitable type of engaging member, locking device, frictional fit or the like. It should be understood that the mounting plate 24 may be slidably mounted to the foot rest 12 in any suitable manner, such as, for example, by a pair of brackets 26, 28 secured to foot rest 12 for slidably receiving the mounting plate 24. An elongated rod 32, having opposed upper and lower ends, 34, 36, respectively, is further provided, with lower end 36 being rotatably mounted to the mounting plate 24 (at 40). An inclinometer 42, such as a digital inclinometer, angle sensor or the like, is secured to the elongated rod 32 for measuring an angular displacement of the elongated rod 32 with respect to the inclined upper surface 20 of the foot rest 12. A measuring member 30 may be further secured to the mounting plate 24. The measuring member 30 has indicia formed thereon indicating an angular displacement of the elongated rod 32, such that the elongated rod 32 and the measuring member 30 form a goniometer. It should be understood that the inclinometer 42 performs the measurement of the patient's range of motion, and the goniometer may be used for calibrating the inclinometer 42.

A retaining bar 44 is secured to the elongated rod 32, adjacent the upper end 34 thereof, with the retaining bar 44 extending substantially orthogonal to the elongated rod 32. It should be understood that the substantially L-shaped retaining bar 44 is shown for exemplary purposes only. The retaining bar 44 is adapted for positioning adjacent or proximate a calf muscle C of the patient when the patient's foot F is received in the foot retainer 22 (about 20 cm below the tuberosity of the tibia in an average adult). Preferably, the retaining bar 44 is slidably mounted on the elongated rod 32 for selectively adjusting a height of the retaining bar 44 with respect to the foot rest 12, allowing the device for measuring range of motion of an ankle 10 to be used by patients having varying heights and body types.

In use, the patient places his or her foot F on the foot retainer 22 and lowers his or her lower leg as much as possible; i.e., the patient stretches in the direction of motion being measured until he or she reaches the maximum tolerable angle. The retaining bar 44 is then lowered to the level of the leg while the patient's foot is held in the foot retainer 22. The inclinometer 42 measures the degree to which the patient can bend his or her ankle, as indicated by the level of the lowered leg. For plantar flexion movement, the foot is positioned on the foot retainer 22 such that the toes point toward the base of the foot rest 12, as shown in Fig. 3. Once in this position, the patient stretches forward to measure plantar flexion movement. To measure dorsiflexion movement, the foot retainer 22 is turned 180° from the position shown in Fig. 3 and the same foot is positioned heel first onto the foot retainer 22, i.e. with the patient facing away from the foot rest 12, such that the toes point toward the top edge of the foot rest 12. Once in this position, the patient stretches forward to measure dorsiflexion movement. For measuring side-to-side motion, the foot is positioned across the foot rest 12, as shown in Fig. 2, and the patient stretches to one side, away from the foot rest 12. To measure the range of motion for the opposite side of the same ankle, the patient can rotate the foot retainer 180° and reposition his or her foot accordingly.

It should be understood that the device 10 may be used in combination with additional measurement devices or aids for precision measurement. For example, one or more foot plate sensors may be positioned under the foot of the patient to compensate for any unwanted motion of the patient, such as elevation of part of the foot during extreme bending of the ankle. As another example, an additional laser pointer or the like may be added, fixed to the elongated rod 32, to identify the internal axis of the measured ankle that joins the two malleoli with respect to one another. Such a laser pointer could be received within the housing of joint 40, for example.

The device for measuring range of motion of an ankle 10 allows for accurate measurement of the ankle joint in all cardinal planes, while simultaneously allowing for adjustment of the axis of rotation by variable placement of the center of rotation. The device 10 allows for controlled measurement of these ranges of motion while the patient's ankle is fully weight bearing (or simulative of full weight bearing position). This provides for an accurate assessment of any alteration in ankle flexibility. The device 10 allows for measurement of the ankle in a functional manner, enabling it to move along three- dimensional axes, e.g., in a forward direction and opposing side directions.

It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.

Claims

1. A device for measuring range of motion of an ankle, comprising:

a foot rest having a base, a pair of sidewalls and an inclined upper surface;

a foot retainer secured to the inclined upper surface of said foot rest, said foot retainer being adapted for releasably receiving a patient's foot;

a mounting plate slidably mounted to one of the pair of sidewalls, wherein said mounting plate is selectively slidable along a direction parallel to the inclined upper surface; an elongated rod having opposed upper and lower ends, the lower end thereof being rotatably mounted to said mounting plate;

an inclinometer secured to said elongated rod for measuring an angular displacement of said elongated rod with respect to the inclined upper surface of said foot rest; and

a retaining bar secured to the elongated rod, adjacent the upper end thereof, said retaining bar extending substantially orthogonal to the elongated rod, said retaining bar being adapted for contacting a leg of the patient when the patient's foot is received in said foot retainer.

2. The device for measuring range of motion of an ankle as recited in claim 1, further comprising a pair of brackets secured to said foot rest for slidably receiving said mounting plate.

3. The device for measuring range of motion of an ankle as recited in claim 1, further comprising a measuring member secured to said mounting plate, the measuring member having indicia formed thereon indicating an angular displacement of the elongated rod, the elongated rod and the measuring member forming a goniometer.

4. The device for measuring range of motion of an ankle as recited in claim 1, wherein said retaining bar is slidably mounted on said elongated rod for selectively adjusting a height of said retaining bar with respect to said foot rest.

5. The device for measuring range of motion of an ankle as recited in claim 1, wherein said foot retainer is rotatable with respect to the inclined upper surface.

6. The device for measuring range of motion of an ankle as recited in claim 1, further comprising at least one strap secured to said foot retainer for releasably securing the patient' s foot thereto.

7. The device for measuring range of motion of an ankle as recited in claim 1, wherein the inclined upper surface is inclined with respect to the base of the foot rest by an angle of approximately 40°.

8. A device for measuring range of motion of an ankle, comprising:

a foot rest having a base, a pair of sidewalls and an inclined upper surface;

a foot retainer pivotably secured to the inclined upper surface of said foot rest, said foot retainer being adapted for releasably receiving a patient's foot;

a mounting plate slidably mounted to one of the pair of sidewalls, wherein said mounting plate is selectively slidable along a direction parallel to the inclined upper surface; a pair of brackets secured to said foot rest for slidably receiving said mounting plate; an elongated rod having opposed upper and lower ends, the lower end thereof being rotatably mounted to said mounting plate;

a retaining bar secured to the elongated rod, adjacent the upper end thereof, said retaining bar extending substantially orthogonal to the elongated rod.

9. The device for measuring range of motion of an ankle as recited in claim 8, further comprising a measuring member fixedly secured to said mounting plate, the measuring member having indicia formed thereon indicating an angular displacement of the elongated rod, the elongated rod and the measuring member forming a goniometer.

10. The device for measuring range of motion of an ankle as recited in claim 8, wherein said retaining bar is slidably mounted on said elongated rod for selectively adjusting a height of said retaining bar with respect to said foot rest.

11. The device for measuring range of motion of an ankle as recited in claim 8, wherein said foot retainer is rotatable with respect to the inclined upper surface.

12. The device for measuring range of motion of an ankle as recited in claim 8, further comprising at least one strap secured to said foot retainer for releasably securing the patient' s foot thereto.

13. The device for measuring range of motion of an ankle as recited in claim 8, wherein the inclined upper surface is inclined with respect to the base of the foot rest by an angle of approximately 40°.

14. A device for measuring range of motion of an ankle, comprising:

a foot rest having a base, a pair of sidewalls and an inclined upper surface; a foot retainer pivotably secured to the inclined upper surface of said foot rest, said foot retainer being adapted for releasably receiving a patient's foot;

a retaining bar slidably mounted on the elongated rod, adjacent the upper end thereof, said retaining bar extending substantially orthogonal to the elongated rod.

15. The device for measuring range of motion of an ankle as recited in claim 14, further comprising a pair of brackets secured to said foot rest for slidably receiving said mounting plate.

16. The device for measuring range of motion of an ankle as recited in claim 14, further comprising a measuring member fixedly secured to said mounting plate, the measuring member having indicia formed thereon indicating an angular displacement of the elongated rod, the elongated rod and the measuring member forming a goniometer.

17. The device for measuring range of motion of an ankle as recited in claim 14, wherein said foot retainer is rotatable with respect to the inclined upper surface.

18. The device for measuring range of motion of an ankle as recited in claim 14, further comprising at least one strap secured to said foot retainer for releasably securing the patient' s foot thereto.

19. The device for measuring range of motion of an ankle as recited in claim 14, wherein the inclined upper surface is inclined with respect to the base of the foot rest by an angle of approximately 40°.