TWI468151B - Isometric dynamometer device for trunk muscles - Google Patents

Description

Isometric muscle strength measuring device for trunk muscle group

The present invention relates to a device for measuring muscle strength, and particularly to an isometric muscle strength measuring device for measuring the muscle strength of the trunk muscle group for performing an isometric muscle force such as a forward bending, a back tilting, a rotation and a side bending. .

The so-called "body muscle group" generally includes the back muscle group and the abdominal muscle group. The trunk muscle group can complete the movements including the front bend, the back tilt, the rotation and the side bend; the trunk muscle group balances the human limb, and the motion coordination The performance of the degree is very important. All kinds of static postures, taking objects, lifting objects and other actions require good trunk muscle group control. In addition, when the human body performs "equal motion", the joint angle remains unchanged and the muscle length is fixed. At this time, the measured muscle strength value is called "isometric muscle strength value" or "static muscle strength value". .

In addition, due to the large strength of the trunk muscle group, when the traditional hand-held force measuring device is used to measure the isometric muscle strength of the trunk muscle group, it is easy to be fixed and the accuracy of the measured value is affected, so it is more suitable for transmission. The isometric muscle strength measuring device of the large trunk muscle group measures the isometric muscle strength value of the trunk muscle group when performing various actions.

At present, the device that can measure the muscle strength of the trunk muscles is more than the energy to measure the isometric muscle strength of the human body before bending and reclining; among them, the dynamometer manufactured by Biodex Corporation of the United States In addition to measuring the isometric muscle strength of the human body in front and back, the Dynamometers series has the function of measuring the strength of the isometric muscles when the human body rotates.

However, the above-mentioned isometric muscle strength measuring devices of the trunk muscle group cannot measure the isometric muscle strength value of the human body during the lateral bending motion; in view of this, the conventional trunk muscle group and the like The long muscle strength measuring device still needs to be improved, so that the function of measuring the muscle strength of the trunk muscle group can be more perfect.

The main object of the present invention is to improve the above disadvantages to provide an isometric muscle strength measuring device for the trunk muscle group, which is capable of measuring the isometric muscle strength of the trunk muscle group during forward bending, reclining, rotation and side bending. Value to provide a complete and accurate muscle strength measurement function for the trunk muscle group.

In order to achieve the foregoing objective, the technical content of the present invention includes: an isometric muscle strength measuring device for a trunk muscle group, comprising: a base; a first twisting force measuring module disposed on the base, the The first twisting force measuring module is provided with a first twisting force measuring device and a pressure blocking member, and the pressure blocking member is detachably connected to the first twisting force measuring device; a carrying module is disposed on the base The carrying module is provided with a rotatable seat and a waisting member, the abutting waist member is detachably disposed on one side of the seat; and a second twisting force measuring module is disposed on the base. The second twisting force measuring module is provided with a second twisting force measuring device and a chest back clamping assembly, and the chest back clamping assembly is detachably connected to the second twisting force detector and located in the seat.

The isometric muscle strength measuring device of the trunk muscle group of the present invention, wherein the base can have a first lifting component, a translational sliding rail and a supporting frame, and the first twisting force measuring module and the supporting frame are connected The second torsion strength measuring module can be connected to the free end of the support frame, and the translational slide rail can be disposed on one side of the first lifting component, and the carrying module can be Slidingly disposed on the translational slide.

The isometric muscle strength measuring device of the trunk muscle group of the present invention, wherein the base is further provided with a second lifting assembly, the second lifting assembly is slidably disposed on the translational sliding rail, and the seat is rotatably provided At the top of the second lifting assembly.

The isometric muscle strength measuring device of the trunk muscle group of the present invention, wherein the first twisting force measuring module is further provided with a connecting seat and an angle adjusting member, and the connecting seat can be fixed to one end of the first lifting component The angle adjusting member is provided with a positioning convex portion and is rotatably positioned on the surface of the connecting seat facing the translation sliding rail, and one end of the first twisting force measuring device can be latched and positioned on the positioning convex portion.

The isometric muscle strength measuring device of the trunk muscle group of the present invention, wherein the angle adjusting member may be provided with at least one arcuate slot, and the at least one arcuate slot may be disposed around the positioning convex portion, the angle The adjustment member may be positioned by the plurality of fasteners abutting the surface of the connector toward the translational slide.

The isometric muscle strength measuring device of the trunk muscle group of the present invention, wherein the positioning convex portion can be disposed at an axial position of the angle adjusting member and is in a non-circular shape, and the first twisting force detector can be provided with The positioning protrusion matches one of the card holes.

The isometric muscle strength measuring device of the trunk muscle group of the present invention, wherein the other end of the first twisting force measuring device can be provided with a set of connectors for inserting and positioning the pressure blocking member.

The isometric muscle strength measuring device of the trunk muscle group of the present invention, wherein the carrying module can further be provided with a rotating disk and two insertion portions, the rotating disk is fixed at the bottom of the seat, and is rotatably connected to the The two insertion portions are respectively connected to the rotating disk at one end, and the other ends are respectively protruded from the two sides of the seat, so that the waist member is inserted and positioned on the two insertion portions. One of them.

The isometric muscle strength measuring device of the trunk muscle group of the present invention, wherein the second twisting force detector can be connected and positioned at a free end of the support frame, and the chest back clamping assembly can be provided with a connecting member and a chest And a connecting member is sleeved and fixed to the second twisting force measuring device, and the connecting member and the end portion of the pressing member are respectively provided with a coaxially opposite sleeve portion and a socket portion, the back portion The end wear setting of the piece is located in the fitting portion and the socket portion.

The isometric muscle strength measuring device of the trunk muscle group of the present invention, wherein the side end of the translational slide rail parallel to the sliding direction may be provided with a positioning rack, and the second lifting component may be provided with a positioning rack. A latch member pivotable to control disengagement or engagement with the positioning rack.

The above and other objects, features, and advantages of the present invention will become more apparent from the aspects of the appended claims. The isometric muscle strength measuring device of the trunk muscle group of the preferred embodiment of the present invention comprises a base 1, a first twisting force measuring module 2, a carrying module 3 and a second twisting force measuring module 4. The first twisting force measuring module 2, the carrying module 3 and the second twisting force measuring module 4 are all disposed on the base 1 , and the carrying module 3 can carry the subject to be measured by the first twisting force The module 2 or the second torsion force measuring module 4 measures the isometric muscle strength of the torso muscle group of the subject.

The pedestal 1 is used for connecting, supporting and arranging the components. In the embodiment, the pedestal 1 can include a first lifting assembly 11 , a translation rail 12 and a support frame 13 . The first lifting assembly 11 can have a housing 111 and a linear actuator 112. The linear actuator 112 can be a pneumatic cylinder, a hydraulic cylinder or an electric cylinder. The linear actuator 112 is disposed on the housing. 111, and one end of the linear actuator 112 protrudes from the housing 111. The translational slide rail 12 can be combined and fixed to one side surface of the housing 111 of the first lifting assembly 11 or integrally formed by one side surface of the housing 111 of the first lifting assembly 11; A positioning rack 121 may be provided at a side end of the 12 parallel to the sliding direction. The support frame 13 can be substantially L-shaped, and one end of the support frame 13 can be fixed to one end of the linear actuator 112 of the first lifting assembly 11 and protrude from one end of the housing 111, and the other end can be roughly Parallel to the direction of the translational slide 12 to form a free end opposite the translational slide 12.

The base 1 can also be provided with a second lifting assembly 14 . The second lifting assembly 14 is slidably disposed on the translation rail 12 . In the embodiment, the second lifting assembly 14 can have a housing 141 . And a linear actuator 142, the linear actuator 142 is disposed in the housing 141, and one end of the linear actuator 142 protrudes from the housing 141. The second lifting assembly 14 is further provided with a latching member 143 at a side end of the housing 141. The latching member 143 is pivotable and opposite to the positioning rack 121 for transmitting and positioning the latching member 143. The racks 121 are engaged with each other for positioning the second lifting assembly 14 when the second lifting assembly 14 is slid to a preset position, and pivoting the latching member 143 to disengage the latching member 143 from the positioning rack 121. The second lifting assembly 14 is controlled to slide relative to the translational slide 12.

The first torsion force measuring module 2 is disposed at one end of the first lifting assembly 11 to be driven up and down by the linear actuator 112 of the first lifting assembly 11; in the embodiment, the first torsion force measuring module The group 2 comprises a connecting seat 21, an angle adjusting member 22, a first twisting force measuring device 23 and a substantially L-shaped resisting member 24. The connecting rod 21 can be fixed to the end of the linear actuator 112 of the first lifting assembly 11 and protrude from the one end of the housing 111, and the connecting seat 21 faces the surface of the translation rail 12 There are a plurality of keyholes (not shown).

As shown in FIG. 2 , the angle adjusting member 22 can be provided with a positioning convex portion 221 and at least one curved slot 222 . The positioning convex portion 221 is in a non-circular shape, and is preferably disposed at the angle adjustment. The axial position of the member 22, the at least one arcuate slot 222 can be annularly disposed on the outer circumference of the positioning protrusion 221; the angle adjusting member 22 can be selectively locked to the plurality of fasteners 25 after adjusting the rotation angle to The plurality of locking holes of the connecting seat 21 are positioned to abut the angle adjusting member 22 on the surface of the connecting seat 21 toward the translational sliding rail 12.

In addition, one end of the first torsion force measuring device 23 is provided with a latching hole 231, and the latching hole 231 is matched with the positioning convex portion 221 of the angle adjusting member 22 to be positioned with each other and the first twisting force is When the detector 23 is coupled to the angle adjuster 22, rotation cannot be generated with respect to the angle adjuster 22. The other end of the first torsion force detector 23 can be connected to the pressure blocking member 24, wherein the first torsion force is applied to the torque arm of the first torsion force detector 23 for facilitating adjustment of the pressure blocking member 24. Preferably, the measuring device 23 is provided with a connecting member 232 at the end for detachably inserting one end of the pressure-reducing member 24, and fixing to a preset position, and fixing the other end of the resisting member 24; It extends in the direction of the translational slide 12 and is preferably covered by a cushion for the human body to apply a force.

Referring to FIG. 1 again, the carrier module 3 is rotatably disposed at one end of the linear actuator 142 of the second lifting assembly 14 protruding from the housing 141 for the second lifting assembly 14 The linear actuator 142 drives the lift and slides over the translation slide 12 through the second lift assembly 14. In this embodiment, the carrying module 3 includes a seat 31, a rotating disc 32, two engaging portions 33 and a waisting member 34; the seat 31 is for the subject to ride, and the seat 31 A strap (not shown) is provided on the strap to the subject's pelvis when the subject rides to the seat 31. The rotating disk 32 is fixed to the bottom of the seat 31, and is preferably connected to the linear actuator 142 of the second lifting assembly 14 at a central position of the rotating disk 32, so that the linear actuator 142 can operate. The direction is the axis, and the preset angle and the positioning are synchronously rotated with the seat 31 (for example, the positioning is performed by using a plurality of clips); further, at least one positioning hole 321 may be disposed on both sides of the rotating disc 32. The positioning hole 321 may be a plurality of equidistantly disposed holes for adjusting the position of the member coupled to the side end of the rotating disk 32. The positioning hole 321 may also be an elongated hole to adjust the combination of the members without a segment. position.

The two insertion portions 33 are respectively disposed on two sides of the seat 31. In the embodiment, the two insertion portions 33 can be selected as L-shaped hollow tubes, and one end of the two insertion portions 33 can be respectively connected. The positioning holes 321 at appropriate positions on the rotating disk 32 can be respectively protruded from the two sides of the seat 31. The abutting member 34 is detachably inserted into one of the two insertion portions 33, and the end surface of the abutting member 34 opposite to the seat 31 can be provided with a cushion to abut against the subject. The ridge (top of the humerus).

As shown in FIG. 3, the second torsion strength measuring module 4 can include a second torsion force detector 41 and a chest back clamping assembly 42. The second torsion force detector 41 can be connected and positioned. At the free end of the support frame 13; the chest-back clamp assembly 42 is detachably coupled to the second torsion force detector 41 and is located on the seat 31, so that when the subject rides on the seat 31, the The chest-back clamping assembly 42 can be clamped to the chest and back sides of the subject to press the force of the subject against the chest-back clamping assembly 42 when the torso is rotated, and the second torsion force measurement is transmitted. 41.

In this embodiment, the chest-back clamping assembly 42 can be optionally provided with a connecting member 421, a chest member 422 and a backing member 423; the connecting member 421 can be a dome-shaped bracket, and the center of the connecting member 421 The position of the connecting member 421 can be respectively fixed to the second torsion force measuring device 41. The two ends of the connecting member 421 can be respectively provided with a set of joints 4211. The chest member 422 is disposed on one side of the connecting member 421. The chest member 422 can be a crotch-shaped bracket, and the closed end of the thoracic member 422 can be covered with a cushion for the chest of the subject to be abutted. The connector portion 4221 is coaxially opposite to the sleeve portion 4211 of the connector member 421; the abutting member 423 is disposed on the other side of the connector member 421, and the abutting member 423 can be The V-shaped bracket is bent at the end, and the backing member 423 can cover the cushion for the back of the subject to be abutted, and the curved end of the backing member 423 sequentially passes through the sleeve of the connecting member 421. The fitting portion 4211 and the sleeve portion 4221 of the chest member 422, and after adjusting the chest member 422 and the backing member 423 to a predetermined distance, the plurality of fasteners 424 (for example, fastening screws) ) Tightly against the chest of the abutment member 422 abuts back member 423 may just be able to maintain the test subject holding chest, back spacing and no longer slide.

Referring to FIG. 4, when the muscle strength of the trunk muscles of the "bending" motion is measured, the chest-back clamping unit 42 is not attached to the second torsion force detector 41. . The subject can ride on the seat 31 of the carrying module 3 and bind the pelvis by the strap, and then linearly actuate the linear actuator 142 of the second lifting assembly 14 or the first lifting assembly 11 Actuator 112, adjusting the height of the seat 31 or the first torsion strength measuring module 2, so that the first torsion force detector 23 is aligned with the third section of the lumbar vertebra of the subject; and, the subject is made When sitting and holding the chest with both hands, the pressure-reducing member 24 can abut against one side of the subject, and the abutting member 34 can abut against the ridge portion of the other side of the subject, The pelvis does not move when the tester bends. Thus, when the subject bends the torso to press against the pressure-reducing member 24, the force received by the pressure-reducing member 24 can be transmitted to the first torsion force detector 23 to be used by the first torsion force detector 23 The corresponding electrical signal is output and displayed on a display (not shown) after calculation, which is convenient for the operator to record.

Similarly, if the isometric muscle strength value of the lateral bending trunk muscle group is measured in the other direction, the latching member 143 can be disengaged from the positioning rack 121 to control the second lifting assembly 14 to slide relative to the translation. The rail 12 slides away from the first lifting assembly 11 to generate sufficient space for the operator to rotate and adjust the angle of the angle adjusting member 22, so that the pressure blocking member 24 is modified to protrude from the other side of the seat 31; Then, the second lifting assembly 14 is slid back to the preset position through the translation rail 12 in the direction of the first lifting assembly 11, and the clamping member 143 is again engaged with the positioning rack 121 to ensure the seat. The chair 31 does not slip during the measurement process. At this time, the pressure-barrier member 24 can abut against the height of the armpit on the side of the body of the subject, and the waist-receiving member 34 needs to be replaced in the insertion portion 33 on the side opposite to the pressure-barrier member 24 to resist Relying on the ridge of the subject, and measuring the length of the muscles of the trunk muscles on the side.

Referring to FIG. 5, when the muscle strength of the trunk muscles of the "front bend" is measured, the chest-back clamp unit 42 is not attached to the second twist force detector 41. The positioning relationship between the rotating disk 32 and the linear actuator 142 of the second lifting assembly 14 can be released, and the seat 31 and the rotating disk 32 can be synchronized with the operating direction of the linear actuator 142. After the rotation is about 90 (or 270) degrees, the fixed position is stabilized, so that the pressure-reducing member 24 can be laterally protruded into the seat 31, so that the subject rides on the seat 31 and is tied by the strap. In the pelvic position, the upper limb of the subject may be located between the pressure-reducing member 24 and the seat back of the seat 31, and the sternum handle of the subject abuts against the pressure-receiving member 24 to apply a force to bend forward. And pressing the resistor 24; the force received by the resistor 24 can be transmitted to the first torsion detector 23 to output a corresponding electrical signal from the first torsion detector 23, and It is displayed on a display (not shown) after calculation, which is convenient for the operator to record.

Referring to FIG. 6, when the muscle strength of the trunk muscles of the "rearward" motion is measured, the chest-back clamping unit 42 is not attached to the second torsion force detector 41. And the pressure-reducing member 24 can also be laterally protruded into the seat 31, and the angle of the pressure-reducing member 24 to the seat back of the seat 31 can be adjusted by adjusting the angle of the angle adjusting member 22. The measurement front bending action is short, so that when the subject rides on the seat 31 and is tied by the strap to fix the pelvic position, the upper limb of the subject can be located on the front side of the pressure-reducing member 24, and is tested The shoulder blade of the scapula is abutted against the pressure-reducing member 24, so as to be pressed back to press against the pressure-receiving member 24; thus, the force received by the pressure-resistant member 24 can be transmitted to the first torsion force detector 23 The first twisting force detector 23 outputs the corresponding electrical signal, and is calculated and displayed on a display screen (not shown) for the operator to record.

Referring to Figures 7 and 8, when the muscle strength of the trunk muscles of the "rotation" motion is measured, the pressure-reducing member 24 can be detached from the socket 232, and the The chest-back clamping assembly 42 is operatively coupled to the second torsion force detector 41. The seat 31 is further slid on the translational slide rail 12 until the top of the subject seated on the seat 31 is located at the second torsion force detector 41 so as to be perpendicular from the second torsion force detector 41. The extended axis can extend through the lumbar vertebrae of the subject. And adjusting the distance between the chest member 422 and the backing member 423, so that the chest member 422 and the back member 423 can be respectively clamped on the upper part of the sternum of the subject and the scapula spine. In this way, when the subject who is fixed to the pelvic position by the band binding is rotated to the left or the right side, the force acting on the chest member 422 and the backing member 423 can be transmitted to the through the connecting member 421. The second twisting force detector 41 outputs the corresponding electrical signal by the second twisting force detector 41, and is calculated and displayed on a display screen (not shown) for the operator to record.

Among them, the subject should maintain his hands in an overlapping process around the torso (holding the chest or holding the abdomen) during the measurement process of the above-mentioned various actions to avoid the support of the hand to provide the body to the torso. The necessary power leads to the impact of the measurement results.

In summary, the isometric muscle strength measuring device of the trunk muscle group of the present invention can measure the trunk muscle group for forward bending, backward tilting, rotation and side bending, etc. by using measuring components with different functions. The isometric muscle strength during the operation provides a perfect and accurate muscle strength measurement function for the trunk muscle group.

While the invention has been described in connection with the preferred embodiments described above, it is not intended to limit the scope of the invention. The technical scope of the invention is protected, and therefore the scope of the invention is defined by the scope of the appended claims.

1. . . Pedestal

11. . . First lifting assembly

111. . . Shell

112. . . Linear actuator

12. . . Translational slide

121. . . Positioning rack

13. . . Support frame

14. . . Second lifting assembly

141. . . Shell

142. . . Linear actuator

143. . . Card assembly

2. . . First twist strength test module

twenty one. . . Connecting seat

twenty two. . . Angle adjustment

221. . . Positioning convex

222. . . Curved slot

twenty three. . . First twist strength detector

231. . . Card hole

232. . . Socket

twenty four. . . Barrier

25. . . Lock firmware

3. . . Carrier module

31. . . Seat

32. . . Rotating disk

321. . . Positioning hole

33. . . Insertion department

34. . . Waist piece

4. . . Second twist strength test module

41. . . Second twist strength detector

42. . . Chest and back clamping assembly

421. . . Connector

4211. . . Fitting

422. . . Chest piece

4221. . . Socket

423. . . Back to back

424. . . Reach firmware

Figure 1 is an exploded perspective view of a preferred embodiment of the present invention.

Figure 2 is a partially enlarged exploded perspective view of a preferred embodiment of the present invention.

Figure 3: Side view of a combination of preferred embodiments of the invention.

Figure 4 is a schematic side elevational view of a side bend implementation of a preferred embodiment of the invention.

Figure 5: A schematic side view of a prior embodiment of the preferred embodiment of the invention.

Figure 6 is a schematic side elevational view of a preferred embodiment of the invention.

Figure 7 is a schematic side view of a rotary embodiment of a preferred embodiment of the invention.

Figure 8 is a schematic plan view showing the rotation of a preferred embodiment of the present invention.

1. . . Pedestal

11. . . First lifting assembly

111. . . Shell

112. . . Linear actuator

12. . . Translational slide

121. . . Positioning rack

13. . . Support frame

14. . . Second lifting assembly

141. . . Shell

142. . . Linear actuator

143. . . Card assembly

2. . . First twist strength test module

twenty one. . . Connecting seat

twenty two. . . Angle adjustment

222. . . Curved slot

twenty three. . . First twist strength detector

232. . . Socket

twenty four. . . Barrier

25. . . Lock firmware

3. . . Carrier module

31. . . Seat

32. . . Rotating disk

321. . . Positioning hole

33. . . Insertion department

34. . . Waist piece

4. . . Second twist strength test module

41. . . Second twist strength detector

42. . . Chest and back clamping assembly

421. . . Connector

4211. . . Fitting

422. . . Chest piece

4221. . . Socket

423. . . Back to back

424. . . Reach firmware

Claims (9)

The isometric muscle strength measuring device of the trunk muscle group comprises: a base; a first twisting force measuring module is disposed on the base, and the first twisting force measuring module is provided with a first twisting force measuring device And a resistor block, the resistor member is detachably connected to the first torsion force detector; a carrier module is disposed on the base, the carrier module is provided with a rotatable seat and a waist The second twisting force measuring module is disposed on the side of the seat, and the second twisting force measuring module is provided with a second twisting force test. And a chest back clamping assembly, the chest back clamping assembly is detachably coupled to the second torsion force detector and located in the seat; wherein the base has a first lifting assembly, a translation slide rail and a support frame, the first twist strength measuring module and the support frame are connected to one end of the first lifting component, and the second twisting force measuring module is connected to the free end of the support frame, the translational slide rail is set The carrier module is slidably disposed on the translation rail on one side of the first lifting assembly. The isometric muscle strength measuring device of the trunk muscle group according to the first aspect of the patent application, wherein the base is further provided with a second lifting component, and the second lifting component is slidably disposed on the translational sliding rail. The seat is rotatably disposed at a top end of the second lifting assembly. The isometric muscle strength measuring device of the trunk muscle group according to the first aspect of the patent application scope, wherein the first twisting force measuring module further has a connecting seat and An angle adjusting member fixed to one end of the first lifting assembly, the angle adjusting member is provided with a positioning convex portion and rotatably positioned on the surface of the connecting seat facing the translation sliding rail, the first twisting force One end of the detector is positioned at the positioning protrusion. The isometric muscle strength measuring device of the trunk muscle group according to the third aspect of the patent application, wherein the angle adjusting member is provided with at least one arcuate slot, and the at least one arcuate slot ring is disposed at the positioning convex portion. In the outer periphery, the angle adjusting member is abutted against the surface of the connecting seat facing the translational slide by a plurality of fasteners. The isometric muscle strength measuring device of the trunk muscle group according to the third aspect of the patent application, wherein the positioning convex portion is disposed at an axial position of the angle adjusting member and is in a non-circular shape, the first twisting force The detector is provided with one of the latching holes matching the positioning convex portion. The isometric muscle strength measuring device of the trunk muscle group according to the third aspect of the patent application, wherein the other end of the first twisting force detector is provided with a set of connectors for inserting and positioning the pressure blocking member. The isometric muscle strength measuring device of the trunk muscle group according to the second aspect of the patent application, wherein the carrying module is further provided with a rotating disk and two insertion portions, and the rotating disk is fixed at the bottom of the seat. The top end of the second lifting assembly is rotatably connected to the rotating disc at one end, and the other end is respectively protruded from the two sides of the seat for positioning the waisting member. One of the two plug-in parts. The isometric muscle strength measuring device of the trunk muscle group according to claim 1 or 2, wherein the second twisting force detector is connected at a free end of the support frame, and the chest back clamping component is provided Have a connector, a chest And a connecting member is sleeved and fixed to the second twisting force measuring device, and the connecting member and the end portion of the pressing member are respectively provided with a coaxially opposite sleeve portion and a socket portion, the back portion The end wear setting of the piece is located in the fitting portion and the socket portion. The isometric muscle strength measuring device of the trunk muscle group according to the second aspect of the patent application, wherein the translational slide rail is provided with a positioning rack parallel to the side end of the sliding direction, and the second lifting component is provided with Positioning the rack relative to the latch member, the latch member being pivotable to control disengagement or engagement with the positioning rack.