CN111449913A

CN111449913A - Lower limb rehabilitation training device and double-foot end actuator thereof

Info

Publication number: CN111449913A
Application number: CN202010376644.6A
Authority: CN
Inventors: 张国庆; 林媛媛; 于凤丽; 王培通; 王玉峰; 齐欣
Original assignee: Shandong Gebu Leshi Intelligent Technology Co ltd
Current assignee: Shandong Gebu Leshi Intelligent Technology Co ltd
Priority date: 2020-05-07
Filing date: 2020-05-07
Publication date: 2020-07-28

Abstract

The invention discloses lower limb rehabilitation training equipment and a double-foot end effector thereof; the double-foot end effector comprises two sets of actuating devices which have the same structure and are arranged in parallel; each set of executing device comprises a linear motion mechanism for realizing the forward and backward movement of the corresponding foot, a lifting mechanism which is connected with the linear motion mechanism and is used for realizing the height lifting of the foot, and an ankle joint rotating mechanism which is connected with the lifting mechanism and is used for realizing the rotation of an ankle joint. The lower limb rehabilitation training device comprises a supporting frame, a weight-losing supporting mechanism used for carrying out weight-losing control on a human body during training, a double-foot end effector used for carrying out gait training, and a pelvis pose adjusting mechanism used for carrying out cooperative adjustment on the position and the posture of the pelvis of the human body during gait training of the lower limbs of the human body so as to realize balance. The invention can realize the joint movement of the lower limbs and the cooperative movement of the pelvis; can effectively improve the walking ability and the balance ability of the patient.

Description

Lower limb rehabilitation training device and double-foot end actuator thereof

Technical Field

The invention relates to the field of rehabilitation equipment, in particular to a biped end effector and lower limb rehabilitation training equipment for gait balance training.

Background

At present, a plurality of lower limb rehabilitation training devices for gait training of patients with lower limb movement dysfunction caused by apoplexy sequelae, spinal cord injury, cerebral apoplexy, craniocerebral trauma, accidents, congenital leg disabilities and the like appear in the market.

But the prior lower limb rehabilitation training equipment has the following defects: on one hand, part of lower limb rehabilitation training equipment is complex in structure, large in size, high in price, inconvenient to use and maintain and not beneficial to use and popularization. On the other hand, most lower limb rehabilitation training devices only pay attention to the recovery of the movement of muscles and joints of the lower limbs, but pay little attention to balance training, the rehabilitation means is single, and the movement of the pelvis is limited.

The research finds that: the pelvis is not only the supporting base of the trunk, but also the driving structure of the lower limbs, and plays an important role in bearing the upper part and the lower part. From the biological and human structure perspectives of human body movement and steering, the pelvis is a pivot for connecting the trunk and the lower limbs and plays an important role in keeping the normal posture of the human body and completing the movement of the lower limbs. In normal walking, the rotation of the trunk is increased by the swinging of the upper limbs, the trunk rotates in the opposite direction to the pelvis, and the pelvis moves up and down, and left and right along the center of gravity. Most dyskinesias and abnormal movement patterns can be found in the absence of pelvic control. The pelvis movement involves a plurality of joints, and the human body can adjust the gravity balance and maintain the body stability through the corresponding movement form of the pelvis.

In view of this, there is a need to improve the prior art, and to develop and design a device for assisting a human body to perform joint movement training of lower limbs during rehabilitation training; and a lower limb rehabilitation training device which can perform joint movement of the lower limbs and also can perform pelvic cooperative movement training so as to realize the simultaneous recovery of walking ability and balance ability.

Disclosure of Invention

The invention aims to overcome the defects in the prior art, and provides a biped end effector which is used for lower limb rehabilitation training equipment, can assist a patient in gait training, namely lower limb joint movement training, and is simple in structure and convenient and fast to use.

As the same inventive concept, the second technical problem solved by the invention is to provide a lower limb rehabilitation training device which can perform lower limb joint movement training and pelvis cooperative movement training at the same time; can effectively improve the walking ability and the balance ability of the patient.

The technical scheme adopted by the invention for solving the first technical problem is as follows: a double-foot end effector is used for lower limb rehabilitation training equipment; the double-foot end effector comprises two sets of executing devices which have the same structure and are arranged in parallel;

each set of actuating device all includes the linear motion mechanism that is used for realizing corresponding foot's antegrade withdrawal, with linear motion mechanism connects and is used for realizing the high lifting of foot's lifting mechanism and with lifting mechanism connects and is used for realizing ankle joint pivoted ankle joint slewing mechanism.

Further, the linear motion mechanism comprises a mounting plate and a mounting seat; a sliding rail is arranged between the mounting plate and the mounting seat, a sliding block is slidably mounted on the sliding rail, a screw rod shaft is rotatably mounted between the mounting plate and the mounting seat, and the screw rod shaft is in threaded connection with the sliding block;

the mounting base is provided with a first motor used for driving the screw shaft to rotate, and the first motor is provided with a first motor encoder.

Further, the lifting mechanism comprises a first driving unit connected with the sliding block and a force arm rod connected with a rotary power output end of the first driving unit, and a mounting groove used for mounting the ankle joint rotating mechanism is formed in the force arm rod.

Further, the ankle joint rotating mechanism comprises a second driving unit arranged in the mounting groove, and a rotary power output end of the second driving unit penetrates out of the arm lever to be connected with the pedal; and a foot sole pressure sensor is arranged on the pedal plate.

Further, the first driving unit comprises a second motor and a first right-angle speed reducer connected with the second motor, a second motor encoder is arranged on the second motor, and a rotary power output end of the first right-angle speed reducer is connected with the force arm rod;

the second driving unit comprises a third motor and a second right-angle speed reducer connected with the third motor, and a third motor encoder is arranged on the third motor; and the rotary power output end of the second right-angle speed reducer is connected with the pedal.

Furthermore, the double-foot end effector also comprises a cover shell with one open end, and the closed end of the cover shell is provided with two avoidance grooves; the linear motion mechanism is positioned in the housing, and a connecting plate connected with the linear motion mechanism extends out of the housing through the avoiding groove and is connected with the lifting mechanism positioned outside the housing.

The technical scheme adopted by the invention for solving the second technical problem is as follows: a lower limb rehabilitation training device is used for gait balance training; the device comprises a supporting frame, a weight-reducing supporting mechanism, a pelvis pose adjusting mechanism and a double-foot end effector for the lower limb rehabilitation training equipment;

the weight-reducing support mechanism is arranged at the top of the support frame and is used for carrying out weight-reducing control and gravity height control on a human body during training;

the double-foot end effector is arranged at the bottom of the supporting frame or on the ground in the supporting frame and is used for assisting the lower limbs of the human body to carry out gait training according to a preset motion trail;

the pelvis pose adjusting mechanism is arranged on the side part of the supporting frame and used for adjusting the position and the posture of the pelvis of the human body in a coordinated mode to achieve balance when gait training is carried out on the lower limbs of the human body.

Further, the weight-losing support mechanism comprises a first rope driver arranged at the top of the support frame, a first rope arranged on the first rope driver and a safety belt connected with the first rope and used for being worn under the armpit of the human body, wherein a first tension sensor is arranged on the first rope;

the first rope driver comprises a first driving motor and a first winch arranged at the output end of the first driving motor, and a fourth motor encoder is arranged on the first driving motor.

Further, the pelvis posture adjusting mechanism comprises a pelvis clamping structure worn on the pelvis of the human body and four adjusting units connected with the pelvis clamping structure and used for adjusting the pelvis of the human body in different directions.

Furthermore, each adjusting unit comprises a second rope driver arranged at the bottom of the supporting frame, a second rope arranged on the second rope driver, and a rope guide frame arranged on a vertical beam of the supporting frame and used for supporting and guiding the second rope; the second rope is connected with the pelvis clamping structure, and a second tension sensor is arranged on the second rope;

the second rope driver comprises a second driving motor and a second winch arranged at the output end of the second driving motor, and a fifth motor encoder is arranged on the second driving motor.

By adopting the technical scheme, the invention has the beneficial effects that:

the invention discloses a biped end effector; the double-foot end effector comprises two sets of actuating devices which have the same structure and are arranged in parallel; each set of executing device comprises a linear motion mechanism for realizing the forward and backward movement of the corresponding foot, a lifting mechanism which is connected with the linear motion mechanism and is used for realizing the height lifting of the foot, and an ankle joint rotating mechanism which is connected with the lifting mechanism and is used for realizing the rotation of the ankle joint. The three mechanisms perform corresponding actions according to a preset motion trail so as to assist the lower limbs of the human body to perform gait training, namely lower limb joint motion training; the structure is simple, and the use is convenient.

The lower limb rehabilitation training device comprises a supporting frame, a weight-reducing supporting mechanism, the double-foot end effector and a pelvis pose adjusting mechanism. The weight-reducing support mechanism is arranged at the top of the support frame and used for carrying out weight-reducing control on a human body during training; the double-foot end effector is arranged at the bottom of the supporting frame or on the ground in the supporting frame and is used for actively or passively assisting the lower limbs of the human body to carry out gait training according to a preset motion track (a normal walking track of a person simulated through a test); and the pelvis posture adjusting mechanism is arranged on the side part of the supporting frame and is used for carrying out cooperative adjustment on the position and the posture of the pelvis of the human body (the pelvis moves cooperatively when the lower limbs move) so as to realize balance when gait training is carried out on the lower limbs of the human body. The lower limb joint movement is realized by controlling the relative position of the pelvis gravity center and the feet, and the rehabilitation requirements of patients with lower limb dyskinesia are met by weight-reducing walking training.

In conclusion, the lower limb rehabilitation training equipment can realize lower limb joint movement training and pelvis cooperative movement training; effectively improves the walking ability and the balance ability of the patient.

Drawings

FIG. 1 is a schematic structural diagram of an embodiment of a lower limb rehabilitation training device of the present invention;

FIG. 2 is a reference view of an embodiment of the present invention in use;

FIG. 3 is a schematic structural view of the weight-reduction support mechanism of FIG. 1;

FIG. 4 is a schematic representation of the operation of a bipedal end effector embodiment of the present invention;

FIG. 5 is a schematic structural view of a bipedal end effector embodiment of the present invention;

FIG. 6 is a state reference diagram of FIG. 5 in a certain use state;

FIG. 7 is a schematic view of the structure of FIG. 5 with the cover omitted;

FIG. 8 is a schematic diagram of the construction of the set of actuators of FIG. 7;

FIG. 9 is an exploded view of the structure of FIG. 8;

FIG. 10 is an exploded view of the first drive unit of FIG. 9;

FIG. 11 is a schematic view of the arm of FIG. 9 in another configuration;

fig. 12 is a schematic structural view of the pelvic posture adjustment mechanism in fig. 1;

in the figure, 1-support frame, 11-cross beam, 12-longitudinal beam, 13-vertical beam, 2-lightening support mechanism, 21-first drive motor, 22-first rope, 23-safety belt, 24-first tension sensor, 3-bipedal end effector, 31-actuator, 311-linear motion mechanism, 3111-mounting plate, 3112-slide rail, 3113-slider, 3114-lead screw shaft, 3115-first motor, 3116-mounting plate, 3117-L-shaped mounting plate, 312-lifting mechanism, 3120-first drive unit, 3121-second motor, 3122-first right angle reducer, 3123-arm lever, 3124-mounting groove, 313-ankle joint rotation mechanism, 3130-second drive unit, 3131-third motor, 3132-second right angle reducer, 3133-foot pedal, 32-avoidance groove, 321-avoidance groove, 4-pelvis posture adjustment mechanism, 41-pelvis clamping mechanism, 42-adjustment rope unit, 422-second tension adjustment rope unit, 421-second motor, 422-second tension adjustment rope guide frame, 424-guide frame, and 3122-first right angle reducer.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The double-foot end effector 3 of the invention belongs to a part of the structure of lower limb rehabilitation training equipment, and the details are directly explained by taking limb rehabilitation equipment as an example.

As shown in the figures 1 and 2, the lower limb rehabilitation training device mainly comprises a support frame 1 (formed by welding a plurality of cross beams 11, longitudinal beams 12 and vertical beams 13), a weight-reducing support mechanism 2, a double-foot end effector 3 and a pelvis pose adjusting mechanism 4.

The weight-reducing support mechanism 2 is arranged at the top of the support frame 1 and is used for carrying out weight-reducing control and gravity height control on a human body during gait balance training; the double-foot end effector 3 is arranged at the bottom of the support frame 1 or on the ground in the support frame 1 and is used for actively or passively assisting the lower limbs of the human body to carry out gait training according to a preset movement track (simulated movement track of normal walking of the human body through a test, see fig. 4); the pelvis pose adjusting mechanism 4 is arranged at the side part of the supporting frame 1 and is used for carrying out cooperative adjustment on the position and the posture of the pelvis of the human body when gait training is carried out on the lower limbs of the human body so as to lead the pelvis of the human body to carry out cooperative motion along with the motion of the lower limbs; to achieve balance.

Besides the above mechanical structure, a controller (usually including a driving module, a storage calculating module and a control module) is required to be matched during specific use, the controller is used for controlling the weight-reduction supporting mechanism 2, the two-foot end effector 3 and the pelvis pose adjusting mechanism 4 to perform corresponding actions, the core of the controller (not shown in the figure) is a programmable P L C or a single chip microcomputer, and the mode of the controller for controlling the mechanisms to perform corresponding actions is conventional for those skilled in the art and is not described herein.

The mechanical structure is explained in detail below:

as shown in fig. 3, in the present embodiment, the weight-loss support mechanism 2 includes a first rope driver disposed on the top of the support frame 1, a first rope 22 disposed on the first rope driver, and a safety belt 23 connected to the first rope 22 and worn under the armpit of the human body, wherein a first tension sensor 24 (preferably, an S-shaped tension sensor) is disposed on the first rope 22; the first rope driver comprises a first driving motor 21 (an alternating current servo motor) and a first winch (not shown in the figure) arranged at the output end of the first driving motor 21 and used for winding and unwinding a rope, a fourth motor encoder (not shown in the figure, the fourth motor encoder and the motor encoder mentioned below are mainly used for feeding back a measured magnetic pole position, a measured rotation angle and a measured rotation speed to the controller, and the working principle and the specific installation thereof are technical means well known in the art and are not described herein; the first driving motor 21, the fourth motor encoder and the first tension sensor 24 are all electrically connected with the controller. The controller determines the driving torque or speed based on the difference between the data transmitted by the first tension sensor 24 and the set weight loss value, thereby controlling the first driving motor 21, ensuring weight loss control.

As shown together in fig. 4 to 11, in the present embodiment, the dual-foot end effector 3 (similar to a treadmill in operation principle) includes two sets of actuators 31 having the same structure and arranged in parallel and a housing 32 with one end open; each set of executing device 31 comprises a linear motion mechanism 311 for realizing the forward and backward movement of the corresponding foot, a lifting mechanism 312 connected with the linear motion mechanism 311 and used for realizing the height lifting of the foot, and an ankle joint rotating mechanism 313 connected with the lifting mechanism 312 and used for realizing the rotation of an ankle joint.

The closed end of the cover 32 is provided with two avoiding grooves 321, the linear motion mechanism 311 is positioned in the cover 32, and a connecting plate (i.e. L-shaped mounting plate 3117) connected with the linear motion mechanism 311 extends out of the cover 32 through the corresponding avoiding groove 321 to be connected with a lifting mechanism 312 positioned outside the cover 32.

In this embodiment, the linear motion mechanism 311 is specifically implemented by that the linear motion mechanism 311 includes an installation plate 3111 and an installation seat 3116, a slide rail 3112 is arranged between the installation plate 3111 and the installation seat 3116, a slide block 3113 is slidably installed on the slide rail 3112, a screw shaft 3114 is rotatably installed between the installation plate 3111 and the installation seat 3116, the screw shaft 3114 is in threaded connection with the slide block 3113, a first motor 3115 is arranged on the installation seat 3116 for driving the screw shaft 3114 to rotate, the rotation of the screw shaft 3114 is converted into reciprocating linear motion of the slide block 3113 on the slide rail 3112 to complete the forward and backward movement of the foot, a transverse extension of the installation plate 3117 shaped like L is fixedly connected with the slide block 3113, a vertical extension extends out of the housing 31132 through a recess 321 to be connected with a lifting mechanism 312 located outside the housing 32, the first motor 3115 is provided with a first motor encoder, and the first motor 3115 and the first motor encoder are electrically connected with a controller.

The lifting mechanism 312 comprises a first driving unit 3120 connected with the slider 3113 by means of an L-shaped mounting plate 3117, a rotary power output end of the first driving unit 3120 penetrates through a vertical extending portion of the L-shaped mounting plate 3117 and is connected with a force arm 3123 through a key connection structure, the force arm 3123 completes a lifting action of a foot in a vertical plane when rotating along with the rotary power output end, and a mounting groove 3125 is arranged on the force arm 3123.

The first driving unit 3120 includes a second motor 3121 and a first right angle reducer 3122 connected to the second motor 3121, a rotational power output end of the first right angle reducer 3122 is connected to the arm lever 3123; the second motor 3121 is provided with a second motor encoder, and the second motor 3121 and the second motor encoder are all connected with the controller electricity.

The ankle joint rotation mechanism 313 includes a second driving unit 3130 disposed in the mounting groove 3125 of the arm-of-force lever 3123 and a foot plate 3133 connected to a rotational power output end (which penetrates out of the arm-of-force lever 3123) of the second driving unit 3130 through a key connection structure, and the foot plate 3133 completes rotation of the ankle joint while rotating with the rotational power output end.

Wherein the second driving unit 3130 includes a third motor 3131 and a second right-angle reducer 3132 connected to the third motor 3131, a rotational power output end of the second right-angle reducer 3132 being connected to the foot pedal 3133; the third motor 3131 is provided with a third motor encoder, and both the third motor 3131 and the third motor encoder are electrically connected to the controller.

The controller can acquire the position of each motion joint based on the displacement signals transmitted by the first motor encoder, the second motor encoder and the third motor encoder, so that the motion state of the lower limb of the patient can be judged; and the first motor 3115, the second motor 3121 and the third motor 3131 are controlled according to a preset movement trajectory, so that the lower limb joint moves according to the preset movement trajectory.

The invention also has the function of human-computer interaction; a foot plate 3133 is provided with a sole pressure sensor electrically connected with the controller for man-machine interaction; the sole pressure sensor is mainly used for monitoring sole pressure signals, and the controller carries out movement intention recognition and movement control on the basis of the sole pressure signals, so that active gait auxiliary training of human body lower limb movement is realized. In addition, the biped end effector 3 including the plantar pressure sensor can form a dynamic balance evaluation system to realize balance training and balance evaluation. The positions of the gravity center and the pressure center of the patient can be obtained by utilizing the plantar pressure sensor, and the balance ability of the patient can be scored through the gravity center track, the rectangular area, the front-back offset, the left-right offset and the like, which are not elaborated herein.

As shown in fig. 12, in the present embodiment, the pelvis posture adjustment mechanism 4 includes a pelvis clamping structure 41 for being worn on the pelvis of the human body and four adjustment units 42 connected to the pelvis clamping structure 41 for performing different orientation adjustments of the pelvis of the human body. Wherein the pelvic clamp structure 41 is a ring-shaped structure (similar to a clip).

Each adjusting unit 42 comprises a second rope driver arranged at the bottom of the supporting frame 1, a second rope 422 arranged on the second rope driver, and a rope guide 423 arranged on the vertical beam 13 of the supporting frame 1 and used for supporting and guiding the second rope 422; a second rope 422 is connected with the pelvis clamping structure 41 to create a force field in the horizontal plane of the center of the pelvis, and a second tension sensor 424 (preferably an S-shaped tension sensor) is arranged on the second rope 422; the second rope driver comprises a second driving motor 421 (alternating current servo motor) and a second winch arranged at the output end of the second driving motor 421, and the second driving motor 421 is also provided with a fifth motor encoder; the second driving motor 421, the fifth motor encoder and the second tension sensor 424 are all electrically connected with the controller.

The controller can obtain the current movement track, stress condition, gravity center offset condition and the like of the pelvis of the human body based on the displacement signals transmitted by the four fifth motor encoders in the pelvis pose adjusting mechanism 4 and the tension signals transmitted by the four second tension sensors 424 (the pressure signals of the sole pressure sensors can also be considered), controls the second driving motors 421 in the four adjusting units 42 to correspondingly act according to the target pelvis track and the gravity center track, drives the pelvis of the human body to horizontally rotate, laterally rotate and rotate forwards and backwards, and realizes the cooperative adjustment of the position and the posture of the pelvis of the human body during gait training.

The following provides a brief explanation of passive and active gait-assisted training to facilitate a thorough understanding of the present embodiment.

Passive gait-assisted training: the double-foot end effector 3 controls the positions of the double feet, the pelvis pose adjusting mechanism 4 controls the pelvis pose, and the two parts are matched to control the movement of the knee, the ankle, the hip joint and the pelvis, so that the weight-reducing walking training is realized.

Active gait assisted training: the device carries out movement intention identification and movement control through a sole pressure sensor, controls the positions of feet and the position and the posture of a pelvis according to the movement intention of a patient, controls the movements of a knee, an ankle, a hip joint and the pelvis in a matching way, stimulates muscle contraction by joint movement, keeps muscle strength, stimulates nerves, leads the brain to participate in movement, carries out trial and error and movement relearning, rebuilds a neural circuit and achieves the aim of rehabilitation.

When the patient is in gait balance training; the double-foot end effector 3, the weight-reducing support mechanism 2 and the pelvis pose adjusting mechanism 4 are mutually matched; when the lower limb joint movement training is carried out, the weight reduction control and the pelvis cooperative movement training are carried out, so that the walking ability and the balance ability of the patient are effectively improved.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, many variations and modifications can be made without departing from the design principle of the present invention, and these should also be considered as falling within the protection scope of the present invention.

Claims

1. A double-foot end effector is used for lower limb rehabilitation training equipment; the double-foot end effector is characterized by comprising two sets of executing devices which have the same structure and are arranged in parallel;

2. The bipedal end effector as claimed in claim 1, wherein said linear motion mechanism includes a mounting plate and a mounting base; a sliding rail is arranged between the mounting plate and the mounting seat, a sliding block is slidably mounted on the sliding rail, a screw rod shaft is rotatably mounted between the mounting plate and the mounting seat, and the screw rod shaft is in threaded connection with the sliding block;

3. The bipedal end effector of claim 2, wherein the lifting mechanism includes a first drive unit coupled to the slider and a lever coupled to a rotary power output of the first drive unit, the lever having a mounting slot for mounting the ankle joint rotation mechanism.

4. The dual foot end effector as claimed in claim 3, wherein the ankle joint rotation mechanism includes a second drive unit disposed in the mounting slot, a rotational power output end of the second drive unit passing through the arm lever to connect with a foot pedal; and a foot sole pressure sensor is arranged on the pedal plate.

5. The biped end effector as claimed in claim 4, wherein the first driving unit comprises a second motor and a first right angle reducer connected with the second motor, the second motor is provided with a second motor encoder, and a rotary power output end of the first right angle reducer is connected with the arm lever;

6. The biped end effector of claim 1 further comprising a casing open at one end, the casing having two avoidance slots at a closed end; the linear motion mechanism is positioned in the housing, and a connecting plate connected with the linear motion mechanism extends out of the housing through the avoiding groove and is connected with the lifting mechanism positioned outside the housing.

7. A lower limb rehabilitation training device is used for gait balance training; the lower limb rehabilitation training device is characterized by comprising a supporting frame, a weight-reducing supporting mechanism, a pelvis pose adjusting mechanism and the double-foot end effector of the lower limb rehabilitation training device, wherein the double-foot end effector is as claimed in any one of claims 1 to 6;

8. The lower limb rehabilitation training device of claim 7, wherein the weight-loss support mechanism comprises a first rope driver arranged at the top of the support frame, a first rope arranged on the first rope driver, and a safety belt connected with the first rope and used for being worn under the armpit of the human body, wherein a first tension sensor is arranged on the first rope;

9. The lower limb rehabilitation training device of claim 7, wherein the pelvic pose adjustment mechanism comprises a pelvic clamp structure for wearing on the human pelvis and four adjustment units coupled to the pelvic clamp structure for making different orientation adjustments to the human pelvis.

10. The lower limb rehabilitation training device of claim 9, wherein each of the adjustment units comprises a second rope driver disposed at the bottom of the support frame, a second rope disposed on the second rope driver, and a rope guide frame disposed on a vertical beam of the support frame for supporting and guiding the second rope; the second rope is connected with the pelvis clamping structure, and a second tension sensor is arranged on the second rope;