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1, ISSUE 2, 2018; ABSTRACT, ORAL PRESENTATION AT THE AOPA’S 101ST NATIONAL ASSEMBLY, SEPT. 26-29, VANCOUVER, CANADA, 2018. 
https://doi.org/10.33137/cpoj.v1i2.32030                                                                      

 

1 

 
OPEN  ACCESS 

 

AOPA’S 101 ST NATIONAL ASSEMBLY ABSTRACTS, SEPTEMBER 26-29, VANCOUVER, CANADA, 2018 
 

ABSTRACT (ORAL PRESENTATION) 

SATISFACTION AND EXPERIENCE WITH THE UNITY SUSPENSION SYSTEM 

Hossein Gholizadeh *1,2, Edward D Lemaire1,3, David Nielen2, Patrick Lebel2  

1Ottawa Hospital Research Institute, Centre for Rehabilitation Research and Development, Ottawa, Canada. 
2Prosthetics & Orthotics, Ottawa Hospital Rehabilitation Centre, Ottawa, Canada. 
3Faculty of Medicine, University of Ottawa, Canada. 

* Email: gholizadeh87@yahoo.com 

 

 

BACKGROUND 

While elevated vacuum suspension systems have some 

benefits over the other suspension approaches 1–5, 

elevated vacuum may not be appropriate for all 

amputees. The Unity sleeveless vacuum suspension 

system was developed to overcome issues related to knee 

range of motion and amputees comfort 6. This study 

compared the Unity suspension system with suction and 

pin/lock systems based on user satisfaction and 

experience with these systems.  

METHODS 

Twelve people with unilateral transtibial amputation 

were fitted with the Ossur Unity elevated vacuum 

suspension system, with 57.2 (SD=15.3) years mean age, 

178.3 (SD=6.4) cm height, and 90.6 (SD=16.4) kg 

weight. Participants completed the Prosthesis Evaluation 

Questionnaire (PEQ) for their current prosthesis and 

again, following a minimum 4 week accommodation 

period, for the Unity suspension system. 

RESULTS 

On average, participants required seven sessions (SD=2) 

for casting, gait training, socket adjustment, and 

troubleshooting before successful fitting. All participants 

mentioned no movement inside the socket and improved 

proprioception (i.e., feel where the prosthetic leg is in 

space) compared to their previous suspension system. 

After completed the study protocol, 75% of participants 

(nine people) preferred to continue with the elevated 

vacuum suspension system since they felt more 

comfortable walking. Two people preferred their original 

pin/lock suspension system because they felt more 

freedom and comfort during kneeling and their job 

required kneeling most of the time. One participant 

preferred to continue with his original suction system 

(Seal-in X5 and one way valve) because he felt more 

pressure around the seal area with Seal-In V and elevated 

vacuum. 

All Prosthesis Evaluation Questionnaire scores improved 

with Unity suspension system (Table 1).  

CONCLUSION 

Amputee satisfaction can be improved with the Unity 

system compared to pin/lock and suction sockets. 

However, Unity may not be appropriate for some 

amputees since there is less freedom and comfort during 

kneeling compared to pin/lock systems. In this study, a 

high functioning group with transtibial amputation (K3, 

K4) was recruited. The Unity system’s effect on comfort 

for people with lower activity levels is still unclear.  

DISCLOSURE 

There is no conflict of interest in this study.  

ACKNOWLEDGMENT 

The authors would like to thank Knut Lechler, Nancy 

Dudek, Emily Sinitski and Kristleifur Kristjansson for 

providing clinical and technical advice and support. This 

study was financially supported by Mitacs and Ossur. All 

prosthetics components were provided by Ossur.  

REFERENCES 

1. Board WJ, Street GM, Caspers C. A comparison of trans-

tibial amputee suction and vacuum socket conditions. Prosthet 

Orthot Int. 2001;25(3):202–9.  

https://doi.org/10.1080/03093640108726603 

Table 1: Prosthesis Evaluation 

Questionnaire scales 

 

 

 

 

 

Validated Scale 
Subjects                

(old prosthesis) 

Subject                     

(UNITY) 

How many % 

improved 

Ambulation (AM) 64.9 81.2 25 

Appearance (AP) 69.2 81.7 18 

Frustration (FR) 57.2 75.0 31 

Perceived Response (PR) 75.5 87.5 16 

Residual Limb Health (RL) 54.9 75.6 38 

Social Burden (SB) 72.5 81.9 13 

Sounds (SO) 61.3 69.9 14 

Utility (UT) 53.4 75.7 42 

Well Being (WB) 60.0 77.8 30 

DOI: https://doi.org/10.33137/cpoj.v1i2.32030 

https://doi.org/10.33137/cpoj.v1i2.32030
mailto:gholizadeh87@yahoo.com
https://doi.org/10.1080/03093640108726603
https://doi.org/10.33137/cpoj.v1i2.32030


 

 

Gholizadeh H, Lemaire E.D, Nielen D, Lebel P. SATISFACTION AND EXPERIENCE WITH THE UNITY SUSPENSION SYSTEM. CANADIAN PROSTHETICS & ORTHOTICS JOURNAL, VOLUME 
1, ISSUE 2, 2018; ABSTRACT, ORAL PRESENTATION AT THE AOPA’S 101ST NATIONAL ASSEMBLY, SEPT. 26-29, VANCOUVER, CANADA, 2018. 
https://doi.org/10.33137/cpoj.v1i2.32030                                                                      

 

2 

 
OPEN  ACCESS 

 

AOPA’S 101 ST NATIONAL ASSEMBLY ABSTRACTS, SEPTEMBER 26-29, VANCOUVER, CANADA, 2018 
 

ABSTRACT (ORAL PRESENTATION) 

2. Gholizadeh H, Lemaire ED, Eshraghi A. The evidence-base 

for elevated vacuum in lower limb prosthetics: Literature 

review and professional feedback. Clin Biomech. 

2016;37:108–16. 

https://doi.org/10.1016/j.clinbiomech.2016.06.005 

3. Arndt B, Caldwell R, Fatone S. Use of a partial foot 

prosthesis with vacuum-assisted suspension: A case study. 

JPO J Prosthet Orthot. 2011;23(2):82–8. doi: 

10.1097/JPO.0b013e318217e5f7 

4. Samitier et al. The benefits of using a vacuum-assisted 

socket system to improve balance and gait in elderly transtibial 

amputees. Prosthet Orthot Int. 2014;40(1):83–8. 

https://doi.org/10.1177/0309364614546927 

5. Sanders et al. Effects of elevated vacuum on in-socket 

residual limb fluid volume: Case study results using 

bioimpedance analysis. J Rehabil Res Dev. 2011;48(10):1231. 
DOI:10.1682/JRRD.2010.11.0219  

6. Seal-In V Catalog page [Internet]. Iceross seal-inV trans-

tibial liner with wave. [online] Available at 

https://assets.ossur.com/library/31253/Iceross Seal-In V 

Catalog page.pdf. 

 

 

 

https://doi.org/10.33137/cpoj.v1i2.32030
https://doi.org/10.1016/j.clinbiomech.2016.06.005
doi:%2010.1097/JPO.0b013e318217e5f7
doi:%2010.1097/JPO.0b013e318217e5f7
https://doi.org/10.1177/0309364614546927
doi:10.1682/JRRD.2010.11.0219
https://assets.ossur.com/library/31253/Iceross%20Seal-In%20V%20Catalog%20page.pdf
https://assets.ossur.com/library/31253/Iceross%20Seal-In%20V%20Catalog%20page.pdf

