Ver.2

Ankle Foot Orthosis
An ankle foot orthosis designed with smooth walking in mind.

GaitSolution Design

What Is GaitSolution Design (GSD)?
Features of GSD
Structure of GSD
Why Does GS Realize Smooth Walking?
Adjustment of GS Functions
Comparison with Other Orthoses
Results of Monitor Use Evaluation
Literature
GSD Specifications

1. What Is GaitSolution Design?
GaitSolution (GS) is an orthosis developed by "pursuingnatural walking." It is endowed with the functions required
for ankle foot orthoses, which have been derived from theresults of gait analysis of a total of more than 100 patientswith hemiplegia.
The GaitSolution Design (GSD) has realized ease in theability of the wearer to wear and remove the problem
restricting wearable shoes by enhancing the design inaddition to superior function as a walking aid equippedwith GS.

2. Features of GSD
The features of GSD are described below in comparison
with conventional orthoses. Shoehorn-type orthoses,
which are currently the most commonly used, produce abraking force during both ankle plantar flexion and dorsiflexion
from a certain angle. The strength of the braking force isadjusted by the material thickness or trimming, but fineadjustment is practically difficult since reversion does not work.
Most orthoses with an ankle joint have a structure which allows
free movement in the dorsiflexion direction by stopping ankle
plantar flexion. The angle to stop plantar flexion can be adjusted
by adjusting the joint part. On the other hand,
GSD has a structure which allows free movement in thedorsiflexion direction by producing a braking force at the timeof ankle plantar flexion from a certain angle. In addition,
the strength of the braking force and the angle at which thebraking force starts to be effective can be adjusted. It is thisfine adjustment for plantar flexion braking of GSD that canrealize the wearer's natural walking. (Fig. 1)

In this manual, stopping joint movement at a certain angle is expressed as
restriction and joint movement while putting on the brakes as "braking."

Comparison of Features of Various Orthoses
Plantar flexion braking
Dorsiflexion braking

Plantar flexion angle restriction
Free dorsiflexion

Plantar flexion braking
Free dorsiflexion

Shoehorn-type Orthosis

Orthosis with ankle joint

GaitSolution

Fig. 13. Structure of GSD
Titanium frame
The adoption of lightweight and durable titanium for theframe has realized lightness and strength. Since deformation
does not appear in the orthosis itself as in the case withconventional plastic orthoses, the force exerted by a hydraulicdamper can be transmitted directly to the lower limb.

Rear entry (Fig. 2)
The wearer can wear the orthosis without raising a foot bytilting the frame forward and inserting his or her foot from therear of the orthosis. Since it is engineered to prevent the framefrom tilting forward, it is easy to install belts with one hand.

Fig. 2

Small foot-ankle assembly
By keeping the shape of the foot-ankle assembly to a minimum,
the wearer can wear various shoes on top of the orthoses.
The need for selecting one-size larger shoes, as was the casewith conventional orthoses, has been eliminated.

Use of water dispersion pads (Fig. 3)
By using water dispersion pads which offer superior
breathability in the parts contacting the body,the wearer can obtain a comfortable wear feel.
The crural area belt can be cut according to the shapeof the lower limb and used as it is.

Fig. 3

Small hydraulic damper (Fig. 4)
A small hydraulic damper built into the ankle joint applies the brake to the movementof plantar flexion by producing a braking force in response to the ankle movement while
walking. The strength of the braking force can be adjusted by turning a screw on top of
the damper.When adjusting the strength, refer to the scales on top of the damper.
A scale of "1" indicates the weakest condition while "4" indicates the strongest condition.
Since the strength can continuously be adjusted,it can be adjusted to 1.8, 2.5 or other scale
adjustments. Select an appropriate strength while observing the gait of the wearer.
The brake applied to the plantar flexion promotes weight bearing on the plegic side with
impact absorption, which realizes smooth walking.

Adjustment of Hydraulic Damper

Fig.4

Ankle angle adjustment mechanism (Fig. 5)
The angle at which a braking force of the hydraulic damper starts to be effective can be
adjusted by replacing an ankle joint part. This angle corresponds to the initial ankle angle
using conventional orthoses. The angle is normally set at the neutral position (0 degrees).
In addition to this, a part with dorsiflexion of 5 degrees has been prepared.

Adjustment of Initial Angle
The initial dorsiflexion angle can be changed to thefollowing 2 variations (0 and 5 degrees):

Adjustment cap: 0 degrees(When the thin type is used)

Adjustment cap: 5 degrees(When the thick type is used)

Fig.5

Three color variations
GSD has the three color variations: the Standard type of quiet color arrangement, the Urban
type of sophisticated color arrangement, and the Sport type of active color arrangement.
(*Refer to page 1 of this manual.)4. Why Does GS Realize Smooth Walking?
Since patients with hemiplegia have difficulty in ensuring the toe clearance
during the swing phase due to resistance in separating the toe from thefloor during the late stance phase while walking, conventional orthoses
are used to assist this point. On the other hand, GS is an orthosis
developed with the assistance of the stance phase as its primary purpose.
Improving the stance phase can improve the entire gait including the swing
phase.

Normal Gait Stance Phase:Three Rocker Functions

Fig.6

Height of Center of Gravity (m)In normal gait the body rotates around the weight-bearing foot during the
stance phase. At this time, the center of rotation shifts from the heel
during the initial stance phase through the ankle during the mid stance phaseto the forefoot during the late stance phase. Such rotations are called rocker
functions while walking since they resemble the movements of a rocking chair(J. Perry, 1992). (Fig. 6)

Vertical Movement of Center ofGravity during Normal Gait
Double Support Phase

Time (sec)Fig.7

Copied from magazine of Igaku-Shoin with permission

With these 3 rocker functions, the center of gravity while walking exhibits
movement resembling a sine curve on which it becomes high during thesingle support phase and low during the double support phase. The sine
-curve-like movement of the center of gravity realizes an efficient gait byuse of gravity. (Fig. 7)

Workings of Muscles in Heel Rocker

Eccentric contractionof knee extensors

Eccentric contractionof dorsiflexors

Fig.8

Fig. 8 shows the workings of muscles in the heel rocker. The floor reaction
force produced in the heel by heel contact works in the ankle plantar flexion
direction. At this time, ankle dorsiflexors such as the pre-tibial muscles work
to ensure tibial progression while applying the brake to plantar flexions by
eccentric contraction.Moreover, the knee extensors work to pull the thighfoward.
By such muscle activities, the body rotates upward and forward towards
foot flat.

Height of Center of Gravity (m)Vertical Movement of Center ofGravity during Gait of Patient with
Hemiplegia without Orthosis
Double support phase
Plegic side stance phase

Plegic side stance phase

Unplegic side stance phase

Time (sec)Fig.9

Copied from magagine of Igaku-Shoin with permission

Height of Center of Gravity (m)With regard to the gait of a patient with hemiplegia, the forward bodyrotation cannot be obtained due to the difficulty of heel contact andinsufficient activities of ankle dorsiflexors and knee extensors in plegic side. Fig. 9shows the vertical movement of the center of gravity in the gait of a patientwith hemiplegia without orthosis. It is found that the time is long and thecenter of gravity does not go upward during the double support phase for theplegic side. (Fig. 9)
The analysis of the gait of more than 100 patients with hemiplegia using orthoses has revealed
that the purpose of ankle foot orthoses is to assist the eccentric contraction of ankle
dorsiflexors in the heel rocker. By performing ankle plantar flexion braking and tibial
progression in the heel rocker using the orthoses, weight bearing on the plegic side
is facilitated to allow forward body rotation.
GS does not assist the ankle rocker to apply the brake to the ankle dorsiflexion during
the mid stance or later phase. From this, it is assumed that GS is suitable for patients
who are capable of heel contact and forward rotation of the center of gravity with theassistance of plantar flexion braking.

Vertical Movement of Center ofGravity during Gait of Patient with
Hemiplegia Using GS
Double support phase
Plegic side stance phase
Unplegic side stance phase

Time (sec)Fig.10

Copied from magagine of Igaku-Shoin with permission

Fig. 10 shows the vertical movement of the center of gravity in the gait of the same
patient as in Fig. 9 using GS. It is found that the center of gravity in the gait using GS
exhibits movement resembling a sine curve by going upwards even during the plegic sidestance phase, although a difference between the plegic side and unplegic side remains.

GS improves patient’s body movement during the latter half of stance phase. It’s not
only from the movement of center of gravity but also by improving alignment inplegic side at initial contact. The figures below show a mechanism to reduce hyper
extension on the knee joint .
a) Gait without Orthosis – Stick picture and ground reaction force vector

Plegic side Non-plegic
strikeside offAt highest Non-plegic
COGside strike

Plegicside offb) Gait Using GSD – Stick picture and ground reaction force vector

Plegic side Non-plegic
strikeside offAt highest Non-plegic
COGside strike

Plegicside off

Fig. 11

Posture and Ground Reaction Force at Plegic Side Strike

Fig. 12
Without orthosis

With GSD

Copied from Literature No.5 with permission

The subject is 75 years old male with left hemiplegia (Lower limb Brunnstrm StageV) with cerebral hemorrhage. He can walk independently inside and outside of his
house. It was 23 years after he had the cerebral hemorrhage. However, significant
knee hyper extension was observed from mid stance to late mid stance in his gait
cycle without orthosis. (Fig. 11a) He started to use GS for the first time when he wastaken the measurement. However, his gait speed was improved and knee hyper
extension at late mid stance was reduced. (Fig. 11b) Significant difference isobserved in lower leg angle and ankle moment at just after plegic initial contact
comparing with or without GS. (Fig. 12) In the gait without orthosis, whole plantar
feet contacts with the lower leg in vertical to the floor. Which means the groundreaction force vector runs anterior to the ankle joint and apply ankle plantar flexion
moment. In the gait with GS, the heel contacts with the lower limb backward tilted
position and the ground reaction force is applied on the heel. Which means slightdorsiflexion moment is applied on the ankle joint. Concerning about the cause of theknee hyper extension after mid stance, in the gait without orthosis, the lower leg ispulled backwards from the calf muscles activation. Also, activation of the hip
extension muscles causes backing away posture and end up doing the knee hyper
extension after mid stance. In the gait with GS, the feet can still contact at the heel
and which reduces early activation of plantar flexor. The knee hyper extension is
reduced from this mechanism.

5. Adjustment of GS Functions
Effects of Plantar Flexion Braking
by Orthoses in Heel Rocker

Appropriate plantar
flexion braking

Excessive

InsufficientFig. 13
Copied from book of IshiyakuPublishers, Inc with permission

GS realizes plantar flexion braking in the heel rocker with a braking force by hydraulic damper.
The strength of braking is very important and it is required to adjust it while observing the gait ofwearers. When plantar flexion braking is satisfactory, the trunk approaches an upright postureand the center of gravity is facilitated to moving upward and forward. When braking is excessive,
the knee is pushed forward with the movement of the knee-ankle assembly and the trunk forward
lean or backward rotation of the pelvis may be observed in compensation for the above. The
wearer may have distaste for being pushed from behind and walk pulling back the hips. Whilefeeling “being pushed from behind due to hard orthosis.” The same phenomenon occurs even inorthoses which stop the plantar flexion of an ankle joint. On the contrary, when plantar flexion
braking is insufficient, the knee stays back and becomes hyperextended. At this time,compensation may be seen such as the truck forward lean. The wearer gets a “sensation that theorthosis is too soft while the same feeling as if not wearing.” (Fig. 13)

Flow Chart for GS Adjustment of Plantar Flexion Braking
Initial stanceDo not change the amount ofplantar flexion braking.

- Long time from heel contact to foot flat
- No excessive knee bending

Initial stance- Short time from heel contact
to foot flat
- Toe contact- Pelvis located at the rear of
the foot-ankle assembly

Mid stance- Knee hyperextension- Trunk forward lean
- Small upward movementof the center of gravity

Late stance- Short stride on theunplegic side
- Difficult to remove thetoe from the floor

Increase plantar flexion braking.
Initial stance- Short time from heel contact to foot flat
- Knee flexion- External rotation occurring aroundthe heel

Mid stance- Knee flexion position- Trunk forward lean
- Small upward movement of the centerof gravity

Decrease plantar flexion braking.
Copied from book of IshiyakuPublishers,Inc with permission

Fig. 14

Adjust plantar flexion braking while observing the entire body, mainly on the knee and the trunk
movements, during the plegic saide stance phase. For adjustment, the opinions of tge wearer isalso important. Fig. 14 shows a flow chart for adjustment for your reference. It is recommended tocheck the braking every one or two weeks during period of initial use of GS since the appropriate
strength of braking varies during this time. Especially for the wearer in the recovery phase, adjust
plantar flexion braking frequently by paying attention to changes in his or her gait.
GS also allows adjustment of the initial ankle angle. Adjust the initial angle while observing theplegic side contact. Adjustment of the angle to dorsiflexion coincides with the increase of braking
and to planterflexion with the decrease of braking.

6. The effect from gait training with GS
In the plegic initial contact, the GS assists eccentric contraction of thedorsiflaxor to draw the lower leg anterior and raise the center of gravity
towards midstance. However, it’s important to train the gait to combine
this movement to the movement in hip, pelvis and trunk to gain efficient
gait pattern from mid stance to terminal stance.
We researched comparing the gait of 8 hemiplegic patient inmaintenance phase before and after training of GS. The subject ishemiplegic out-patients in rehabilitation. In this 3 weeks, patients use
GS daily and the PTs implement gait training with GS once to threetimes a week. In the gait training PTs ask patient to put the knee in
extended position as much as possible. The gaits with or without GS,
before and after the gait training are compared. Fig.15 shows a typicalresults of the ankle plantar flexion moment before the gait training withand without GS. It is beneficial to focus on late mid stance because thehemiplegic gait shows reduction of the planter flexion moment at thisstage. The maximum planter flexion moment on late mid stancewithout orthosis shows significant dispersion and the average is
18.1Nm. Just after donning GS also shows significant dispersion andthe average is 28.3Nm. However, as the patients get used to thetraining, the dispersion is reduced and the average become 44.8Nm.
As the GS cannot apply planter flexion moment on late mid stance, thisresult shows possibility of change in the muscle activation of thepatients after improvement at initial contact.
Fig.16 shows the results of several parameters (The Gait speed, themaximum planter flexion moment and the duration of pre swing) which
has significant difference. The duration of pre swing means from
non-plegic side initial contact at plegic late mid stance to plegic side off
the floor. The shorter duration of pre swing means earlier plegic side
off. Each of the parameters improved using GS and also they are
improved even when the patients walks without GS. This shows theeffect from GS is not an instantaneous effect but permanent effect fromgait training.

The typical examples of the ankle plantar flexion moment

Without orthosis,
before training

With GS,
before training

With GS,after training

Fig.15Comparison, before and after the training with GSD

GSD
Without
orthosis

Beforetraining

After
training

The maximum ankle planter
flexion moment (Nm/kg m)

Gait speed (m/s)

Gait speed

The maximum ankle
planter flexion moment

GSD
Without
orthosis

Beforetraining

After
training

The duration of pre swing (s)To make the figures simple, we showed theaverage ±SD here.
However the non-parametric is used to conduct
actual statistical tests.

The duration of
pre swing

GSD
Without
orthosis

Beforetraining

After
training

Fig.16

7. Frequently Asked Questions
Q：Is the GS only for the patients with high gait ability around
Br.Stage V?
A：The feature, braking planter flexion with GS is basis of bipedal gait. Every patients needs this planter flexion braking
feature itself. Especially, when somebody needs to walk
down the slope, he or she needs wider ankle plantar flexion
range. At that time, they will feel benefit from GS comparedwith other orthosis type. However, the structure of GS
doesn’t apply any braking force to dorsal flexion movement.
Which means to the users with weaker planter flexor andtend to experience knee buckling, GS can be unstable. At
that time, it’s better to use orthosis with steel uprights andadd dorsiflexion stopper in the medial side of the joint. Also,
GSD which makes much accounts of shoes donning, hassmaller foot component and the reduction force to Varus
deformity is weaker. You can use GS joint to build plastic
orthosis or steel uprights orthosis apart from GSD when theuser’s Varus deformity is strong.

Q：I want to use GSD indoor without shoes. What can I do for
this?
A：GSD is intended to use with shoes on. Therefore use of the
GSD indoor without shoes is not recommended. Basically,
it’s better to use GSD with shoes outdoor. When you want to
use GSD indoor, you could use Gait Fix (Room shoes
designed for GSD) or just use other orthosis type.

ゲイトフィックス

11

Q：Is the planter flexion force featured in GS same asconventional shoe-horn type orthosis?

With or without ankle joint, location of the flexion.
(Comparison between the GSD anda shoe-horn type orthosis)
GSD
The ankle joint is
at the ankle

The foot component
in the orthosis moves
towards plantar flexion
from ankle groundreaction force

A shoe-horn type orthosis
The ankle joint is
not at the ankle

The ankle groundreaction force doesn’t
create plantar flexion
on ankle joint

Fig.17

A：It is clear that a shoe-horn type orthosis can move towards
plantar flexion. However, when considering initial contact in
the gait cycle, the GS and a shoe-horn type orthosis has
different features. (Fig.17) The ground reaction force on theheel appears at initial contact. When we consider the ankle
joint in an orthosis as a fulcrum on a lever, the structure likeDS has ankle joints and the reaction force runs posterior to
the joint. Which moves the foot component in the orthosis
towards plantar flexion. This is same in the normal footmovement in a gait cycle. On the other hand, a shoe-horn
type orthosis doesn’t have joint but still it moves throughdeformation of posterior ankle part. In this case, the groundreaction force runs around this center of movement, afulcrum on a lever. The force applied on the fulcrum cannot
create this rotational movement. When you wear ashoe-horn type orthosis and intend to planter flex the ankle
at heel contact, you need to push your foot onto your orthosis. This motion activates planter flexors. However, as
shown in Fig.12, the activation of planter flexors on earlystance phase leads to unnatural gait pattern. Therefore ashoe-horn type orthosis without ankle joint has disadvantage
compared to GS witch aims to creates ankle rocker movement.

12Color Variations

Standard

Urban

Quiet color arrangement which matchessurroundings by a warm castSport

Sophisticated monotone color arrangement
which gives an urban impression

Sporty color arrangement with orange as
the key color which cannot be ignored*These specifications and equipment are subject to changes without prior notice.
The body color may appear differently from the actual color in relation to exposure or printing ink.

Specifications

Functions- Braking range: From the neutral position, setting 15 degreesof plantar flexion is possible. No braking for movement of
dorsiflexion.
- Braking force adjustment range: Non-step adjustment from 2
Nm to 20 Nm.
- Initial angle range: Changeable for 2 positions of 0 or 5 degrees
of dorsiflexion by exchanging parts- Weight: 370 g

Dimensions- Circumference of crural area: 260 mm - 400 mm *1- Foot length: 230 mm - 260 mm *2*1: For the crural area belt and the foot belt, special belts cuttable to any
appropriate length are used.
*2: If there is excessive deformity or the length is out of the range above,
use the GaitSolution of the plastic or metal strut type manufactured by order.

Indications- Hemiplegia, peroneal paralysis, etc.
- Weight limit: 70 kg

Incompatible conditions- When a correction force by an orthosis is required for significant
spasticity or deformity- Significant sensory disturbance- Extreme back knee
* A therapist or prosthetist & orthotist (P&O) should select an orthosis
under the guidance of a doctor after confirming the technical data.
Manufacturer

Pacific Supply Co.,Ltd

Headquarters:
1-12-1, Goryo, Daito-Shi, Osaka,574-0064,JAPAN
Phone : +81-72-875-8013
Fax : +81-72-875-8017
E-mail: oversea@p-supply.co.jp

Joint Development
Planning & Development: KAWAMURA GISHI CO., LTD.
Theory of Human Gait: Prof. Sumiko Yamamoto, International University of Health and Welfare/Graduate School
Design: GK Dynamics Inc.
This research was conducted by a grant from the New Energy and Industrial Technology Development Organization.

2019.08