Nabtesco Symphony NK-6 User manual

User’s Guide
6-Bar Hydraulic Knee Joint
NK-6 Symphony
6 -Bar Hydraulic Knee NK-6
Introduction
Thank you for using the NK-6 Symphony.
This product is a prosthetic knee joint
which ensures high stability of stance
and excellent ability to respond to the
walking speed through unique 6-bar
linkage system and hydraulic cylinder.
Before using the product, read this
User’s Guide, and understand the correct
procedures for using. Keep it handy for
future reference.
For Users

P.1
Important Information
■Intended purpose of NK-6 Symphony
NK-6 Symphony was designed and ismanufactured
for use as an artificial knee joint by above-knee,
knee disarticulation, and hip disarticulation. Do not
use NK-6 Symphony for any other purposes.
For hip prostheses, it is recommended to use a
torsion adapter to prevent application of large
torsion to NK-6 Symphony.
This device is intended for single patient multiple
use.
For the specifications for NK-6 Symphony, see 4.
Outline of the Product.
WARN NG
Do not use NK-6 Symphony outside of
the specification range. Do not modify
the main body or parts.
Doing so can cause injury or damage
NK-6 Symphony.
■Cautions for handling NK-6 Symphony safely
Nabtesco Corporation (hereinafter, referred to as
Nabtesco) cannot foresee all of potential residual
risks of NK-6 Symphony and risks resulting from
human errors and usageenvironment.
Although there are a lot of instructions and
prohibitions for handling NK-6 Symphony
(assembling, adjusting and maintaining the
prosthesis), all these matters cannot be described in
this document or on the warning labels on the body
of NK-6 Symphony.
Therefore, when handling NK-6 Symphony, it is
necessary not only to observe the precautions
stated in this document, but also to take safety
measures necessary for prosthesis knee joint.
Particularly important matters concerning the safe
handling of NK-6 Symphony are describedbelow.
If you have a serious incident related to NK-6
Symphony, please report it to the manufacturer
(contact information on the back cover) and the
competent authority in your country.
■Read this document thoroughly
Before handling NK-6 Symphony, thoroughly read
this document, and sufficiently understand the
contents. Strictly observe the safety precautions
stated in the document.

P.2
About This Document
■Target of this document
This document is intended for the prosthetic
user of NK-6 Symphony.
It covers the following references: NK-6, NK-
6SH, NK-6+L and KN-6SH+L.
■Copy right
Nabtesco owns the copyright for this
document. It is not permitted to duplicate any
part of drawings and technical documents
including this document by any means
(copying or recording on electronic media)
without our prior authorization.
When you have questions about the copyright
of this document for copy or reference, contact
Nabtesco.
■When this document is lost or damaged
If this document or any related document is lost
or damaged, immediately ask the Local sales
representative or Distributor (hereinafter,
referred to as the Distributor) to reissue it.
Handling NK-6 Symphony without this
document can cause accidents.
■Information
The information on this manual is subject to
change without prior notice for product
improvement.

P.3
6 - Bar Hydraulic Knee NK-6
Contents
1. Safety Precautions.............................................. P.4
1-1 Definition of Symbols..................................... P.4
1-2 Mandatory Precautions ................................. P.5
2. Basic Construction and Operational Principle..... P.9
2-1 Basic Construction ........................................ P.9
2-2 Operational Principle..................................... P.9
3. Before Use........................................................ P.10
3-1 How to Activate the “Stance-Flexion”
Function ...................................................... P.10
3-2 Procedures for Operating the Selective
Lock (Optional Function) ............................. P.11
3-3 Precautions for Operating the Selective
Lock ............................................................ P.12
3-4 Precautions When Sitting in and
Standing up from a Chair ............................ P.13
3-5 Precautions When Wiping Surface Dirt ....... P.13
4. Troubleshooting................................................ P.14
5. Outline of the Product....................................... P.15
6. Disposal............................................................ P.16
7. Symbols Used .................................................. P.17
7-1 UDI Label (Packing Box)............................. P.17
7-2 Body Mass Limit Label (Knee Joint Body)... P.17
7-3 Product Type Label (Knee Joint Body)........ P.17

P.4
1. Safety Precautions
1-1 Contraindications
- Person who cannot understand how to
use the knee and caution for use
- Person who has problem and pain on
the residual limb
- Person who weighs over 125kg (if
high-active user: over 100kg)
- Use for any sports which give high
impact on the knee
1-2 Definition of Symbols
WARN NG
Indicates a potentially
hazardous situation which,
if not avoided, could result
in death or serious injury.
CAUT ON
Indicates a potentially
hazardous situation which,
if not avoided, may result in
minor or moderate injury or
property damage.
Indicates a general caution
to be observed.
PROH B T ON
Indicates prohibition of a
specific action.
MANDATORY
ACT ON
Indicates obligation of a
specific action.

P.5
MANDATORY
ACT ON
Hand the separate
User’s Guide to the
user and explain the
instructions for use.
Improper use can cause a fall or
injury.
MANDATORY
ACT ON
This product shall be
used as a prosthetic
knee joint. Never use it
for other purposes.
MANDATORY
ACT ON
We do not warrant the product
against damage caused by use
for any unintended purpose.
WARN NG
Upon detecting any
abnormal noise, play, or
drop in hydraulic
resistance, discontinue
use and contact your
local sales
representative/dealer.
Continued use despite a detected
abnormality may cause damage
of parts, leading to a fall.
1-3 Mandatory Precautions
DO NOT undertake any maintenance
actions on the device. Maintenance must
be carried out by a professional at least
every 2 years.

P.6
PROH B T ON
NK-
6 Symphony was tested for 3
million walking cycles with load of
125kg which corresponds to the
average working distance within
about 3 years. We will not assume
liability for ageing or damage of the
product. If used to a person who
weighs over 125 kg, d
amage of
parts may occur, leading to a fail.
This, however, does not preclude
loading and unloading of baggage,
etc. occurring in daily life.
*)Body mass limit not be exceeded!
For specific conditions and limitations of use see
manufacture’s written instructions on intended use!
DO NOT use for a
person who weighs
over 125 kg.
PROH B T ON
PROH B T ON
Specific condition: For persons on a
high activity level and persons
wearing a hip prosthesis, the weight
limit shall be 100 kg.
DO NOT place the hand
behind the knee when
flexing the knee.
DO NOT touch the knee
when extending it.
PROH B T ON
Risk of fire or explosion.
Your hand can be caught, thereby
causing injury.
Never attempt to
disassemble or modify
the knee joint.
Never attempt to
heat or put in a fire
Parts may be damaged, thereby
causing a fall.
ISO 10328-P6-125kg *
)

P.7
CAUT ON
Instructions for storage
PROH B T ON
DO NOT put anything on
the product. DO NOT
step on it.
DO NOT put the product in
a high place. DO NOT
place it against something
in an unstable state.
PROH B T ON
The product may drop or fall
down, thereby causing damage
to parts.
PROH B T ON
Parts may be damaged.
DO NOT store the
product where the
temperature may exceed
the range of -20 to 50°C.
Parts may be deteriorated or
deformed, thereby causing
failure.
PROH B T ON
DO NOT leave the product
in a place where it may be
exposed to water or
moisture.
Parts may rust, thereby causing
failure.

P.8
Do not use the product
where the outdoor
temperature is lower than
–
20°C.
PROH B T ON
The lubricant and rubber parts
may harden, thereby causing
failure.
The plastic parts may be
deformed, thereby causing
failure.
Do not use the product
near open flame or where
the temperature exceeds
50°C.
PROH B T ON
Parts may be damaged, thereby
causing a fall.
DO NOT jump down from a
high place nor play active
sports to intentionally give
strong impact to the product.
Instructions for use
PROH B T ON
Could result in rusting,
discoloration, desiccation of the
grease, could result in a
malfunction and abnormal noises.
DO NOT contact liquids
such as water, salt water,
chlorinated water, soapy
water, gel soap, body fluids
and exudates.
DO NOT use any detergent
or solvent (thinner) for
cleaning it.
PROH B T ON

P.9
2. Basic Construction and Operational Principle
2-1 Basic Construction
The NK-6 Symphony consists of a 6-bar
linkage which controls the stance phase and
a hydraulic cylinder which controls the swing
phase. The selective lock with which the
user can lock the knee by himself/herself
can be chosen at the user’s option. (Model:
NK-6+L, NK-6SH+L)
2-2 Operational Principle
The geometric self-locking system reliably
functions while the prosthesis is in contact
with the floor, thus preventing abrupt
buckling. When the prosthesis leaves the
floor, the hydraulic cylinder functions,
providing cadence responsive swing control.
Fig. 2 Walking on a Level Floor
Hydraulic
cylinder
Stance
-
Flexion
Hydraulic
cylinder
Selective lock
(optional)
Stance-flexion rubber
6-bar linkage
(p
-
MRS
system)
Fig. 1 Main Components
Stance-flexion stiffness
adjusting screw Extension assist
spring adjusting
screw

P.10
~10°
Fig. 3 Differences in self-lock function
depending on loading method
3. Before Use
3-1 How to Activate the
“Stance-Flexion” Function
Fig. 3 shows how to load the prosthesis
equipped with this knee joint. When the
weight is placed on the heel as shown in
the left figure while the knee is completely
extended, the knee is automatically locked
(self-locked) and slightly flexed (stance-
flexion). The maximum flexion angle is 10°
depending on the loading method and the
setting of the adjustment. If the weight is
placed on the toe as shown in the right
figure, the lock is released.
CAUT ON
Until getting used to use the product,
place your weight on the prosthesis
while holding on the parallel bars, and
confirm the self-locking function.
Thoroughly understand the mechanism
and the function prior to use.
CAUT ON
In a standing posture, put the prosthesis
slightly forward, and weight on the heel
while fully extending the knee. If the
weight is placed when the knee is not
fully extended or prior to toe-off, knee
buckling may occur, and the user may fall
down. Particularly users who have a
habit of standing with their prostheses
slightly backward shall keep this in mind.

P.11
(NK-6+L, NK-6SH+L)
3-2 Procedures for Operating the
Selective Lock (Optional Function)
The selective lock is to be operated by the
user. The user shall thoroughly understand
the operating procedures.
The selective lock mechanism has a switch
above the knee joint to switch the lock
mode on or off. However, the lock switch
cannot be operated while the knee is
flexed. The joint can be locked when the
knee is fully extended.
[Locking procedure]
As shown in Fig. 4, slide the lock switch in
front of the knee plate in the arrow
direction.
[Unlocking procedure]
As shown in Fig. 5, slide the lock switch in
front of the knee plate in the arrow
direction.
Knee plate
Lock switch
Fig. 4 Locking Procedure
Fig. 5 Unlocking Procedure

P.12
(NK-6+L, NK-6SH+L)
3-3 Precautions for Operating the
Selective Lock
[Precautions for locking operation]
Before starting to walk, make sure that
the selective lock is securely activated.
To operate the selective lock, slide the
switch surely to the position shown in
Fig.
4. (A click will sound.) Although the
lock can be activated before the position
shown in Fig. 4, the lock parts may be
damaged if the product is used in such a
state.
[Precautions for unlocking operation]
After releasing the selective lock, make
sure that the knee can be normally flexed
before starting to walk.
To release the selective lock, slide the
switch surely to the position shown in
Fig.
5. (A click will sound.) The lock
cannot be released if the switch is
stopped before the position shown in Fig.
5. Slide it correctly.
[Cosmetic foam cover]
Note that the cosmetic foam cover may be
broken depending on the way of operating
the selective lock if the lock is used with
the cover fitted.
CAUT ON
CAUT ON
CAUT ON
CAUT ON

P.13
3-4 Precautions When Sitting in and
Standing up from a Chair
▪ When sitting in a chair, never place the
hand behind the knee. The hand can be
caught in the swaying part of the
hydraulic cylinder, causing serious injury.
▪ When standing up from a chair, never
place the hand on the knee. Fingers can
be caught between the knee plate and
the front link, causing serious injury. For
ease of standing up from a chair, placing
hands on the armrests or on the seating
face* is recommended.
* In addition to the above, placing a hand
on the socket or placing both hands on
the sound leg also facilitate standing up
from a chair. Provide instructions on the
safe method according to the user's
circumstances.
3-5 Precautions When Wiping Surface
Dirt
If necessary, wipe the surface with a soft
cloth moistened with fresh water.
Make sure that no moisture or lint from
the cloth remains after wiping. Rust and
lint caught in the knee may cause
abnormalities in the rotating
part and
affect the bending and stretching of the
knee.
Fig. 6 Recommended Posture When
Standing up from a Chair
WARN NG
CAUT ON

P.14
4. Troubleshooting
Status Items to be
checked Countermeasures
The self-lock
cannot be
activated.
Check if body
weight is
applied properly.
Practice how to fully
apply body weight to
the heel.
Check for
proper
alignment.
Adjust the alignment
so that body weight
can be fully applied to
the heel (See 3-2-1).
Check if the
foot is
appropriate.
Select a foot with
which body weight
can be fully applied to
the heel.
The above
measures
cannot resolve
the problem.
Contact your
prosthetist.
The joint does
not fully extend
before the heel
contacts to the
ground.
Check if the
adjusting valve
(E) on the
extension side
of the hydraulic
cylinder is not
tightened
excessively.
Contact your
prosthetist.
The self-lock is
not released
unintentionally,
thereby causing
sticking.
Check if
smooth heel-to-
toe weight shift
is achieved
while walking.
Practice how to walk
to place sufficient
load on the toe when
pushing off the
prosthesis.
The above
measures
cannot resolve
the problem.
Contact your
prosthetist.
The selective
lock cannot be
activated.
Check if the
knee joint is
fully extended.
When operating the
switch, fully extend
the knee.
Check if the
cosmetic foam
cover is not
involved.
Take care that the
cosmetic foam cover
is not caught.
The above
measures
cannot resolve
the problem.
Contact your
prosthetist.
Abnormal noise
or rattling
occurred.
Check if a
foreign object is
caught in the
moving part.
Remove it if possible.
The above
measures
cannot resolve
the problem.
Contact your
prosthetist.

P.15
5. Outline of the Product
●Specifications
Model No. NK-6 NK-6+L NK-6SH NK-6SH+L
Proximal
Connection Male Pyramid Adapter Screw Head
Selective Lock –
O
–
O
Total Length 197mm 191mm
A ref.
measurement 14mm 14.5mm
B ref.
measurement 156mm 156mm
Weight 920 g 970 g 960 g 1010 g
Max. Knee
Flexion Angle
170°
Material Titanium & Aluminum
Max. Body
Weight
125kg (100kg For Hip Prosthesis & High Active User)
Compliance with ISO 10328 P6 (A-125kg)
Mobility Grade Active ~ High Active (K-Level 3+4, Mobility Class 3+4)
* These specifications are subject to changes without prior notice.
●Lifetime: 6 years
● Features
Smooth walking
The product is named “Symphony” because the
knee smoothly harmonizes between the stance
phase and swing phase control. The p-MRS
system controls shifting from the stance phase to
the swing phase seamlessly.
High stability of stance and Stance-Flexion function
The 6-bar linkage using the p-MRS system
identifies floor reaction force positions and
controls the knee stability. The Stance-Flexion
feature will reduce an impact at the heel strike and
also reduce bobbing of center-of-mass.
Locking of knee by selective lock (optional)
The user can lock the knee by himself/herself.
Whenever the user needs stability, for example,
while working at standing posture, walking on
snowy road, in strong winds or on irregular
ground, he/she can lock his/her knee to
completely prevent knee buckling.
Fig. 7 Installation Height
B
A

P.16
6. Disposal
The table below shows the materials of the
NK-6 Symphony knee unit in each component.
When disposing of the knee joint, comply with
the rules stipulated in the local community.
If you return it to Nabtesco after
giving such a notification, we will
dispose of it for you.
Part name
Classification
of material Remarks
1 Alignment block Metal
Pyramid type:
titanium alloy
Screw head type:
iron alloy
2 Lever Metal Aluminum alloy
3 Knee plate Metal Aluminum alloy
4 Knee cover Plastic Refer to each material
symbol on each.
5 Rear link Metal Aluminum alloy
6 Front link Metal Titanium alloy
7 Hydraulic cylinder Metal
Body: aluminum alloy
Piston: iron alloy
O-ring: rubber
8 Front link cover
Base bracket cover Plastic Refer to each material symbol on each.
9 Base link
Supplementary link Metal Titanium alloy
10 Spring Metal Iron alloy
11 Stance-flexion rubber Rubber
12 Alignment block Metal Titanium alloy
EU

P.17
7. Symbols Used
7-1 UDI Label (Packing Box)
Legal manufacturer Made date
Medical device
Item number
Serial number
Global Trade
Item Number
Authorized representative for EU countries
The maximum and minimum temperatures for
storing, transporting, and using the product.
Declaration of conformity according to the
European Regulation 2017/745
Single patient multiple use
7-2 Body Mass Limit Label (Knee Joint Body)
■ K Level (MOB)
K1 Level (MOB1): User can move to a bed or
chair, and can walk on a flat surface indoors at a
constant speed.
K2 Level (MOB2): User can handle small
environmental barriers such as curbs, steps, or
irregular ground both indoors and around the home.
K3 Level (MOB3): User can handle most
environmental barriers and can walk at different
speeds. In addition to simple walking, he/she can
do light work and exercise as well.
K4 Level (MOB4): User has physical abilities
higher than basic walking; children, athletes, etc.
7-3 Product Type Label (Knee Joint Body)
A Product type
B Serial number
Declaration of conformity according to the
European Regulation 2017/745
MAX. WEIGHT
~K3 (M0B3): 125kg
K4
(M0B4):100kg
Body mass limit not
to be exceeded.
D
SN
EC
REP
-
20°C
-
4°F
+50°C
122°F
REF
A
B
N0.
Nabtesco
MADE IN JAPAN

Document Number: 81-SS00085E (ver.2)
Data of issue: July 1, 2021
Nabtesco Corporation
Manufacturer
Nabtesco Corporation
Accessibility Innovations Company
Assistive Products Department
35, Uozakihama-machi Higashinada-ku
Kobe, Japan 658-0024
TEL: [phone]
FAX: [phone]
https://welfare.nabtesco.com
Authorized representative for EU countries
PROTEOR SAS
6 rue de la Redoute
21850 Saint-Apollinaire
France
TEL: [phone]
FAX: [phone]
[email protected]
Contact