







































All articles are permanently available online to the public without restrictions or subscription 

fees. All articles are free to be used, cited, and distributed, on condition that appropriate 

acknowledgment is included. Authors are the copyright holders of their original 

contributions and grant the Canadian Online Publication Group (COPG) a license to 

publish the article and identify itself as the original publisher. CPOJ articles are licensed 

under the Creative Commons Attribution 4.0 International License.   

 

CPOJ Website: https://jps.library.utoronto.ca/index.php/cpoj/index 

Editorial Office: cpoj@online-publication.com    

ISSN: 2561-987X 

CPOJ is a member of, and subscribes to the principles of, the Committee on Publication 

Ethics (COPE).   

 

 

VOLUME 3, ISSUE 2 

 2020 

 

RESEARCH ARTICLE 

Seth M, Hou W, Gyrates L.R, Galassi J.P, Limber E.M. Effect of transtibial prosthesis mass on gait asymmetries. Canadian Prosthetics & Orthotics Journal. 

2020;Volume 3, Issue 2, No.5. https://doi.org/10.33137/cpoj.v3i2.34609 

https://online-publication.com/wp/
http://creativecommons.org/licenses/by/4.0/
https://jps.library.utoronto.ca/index.php/cpoj/index
mailto:cpoj@online-publication.com
https://publicationethics.org/about/our-organisation
https://publicationethics.org/about/our-organisation
https://publicationethics.org/members/canadian-prosthetics-orthotics-journal
https://doi.org/10.33137/cpoj.v3i2.34609


 

1 

Seth M, Hou W, Goyarts L.R, Galassi J.P, Lamberg E.M. Effect of transtibial prosthesis mass on gait asymmetries. Canadian Prosthetics & Orthotics Journal. 
2020;Volume 3, Issue 2, No.5. https://doi.org/10.33137/cpoj.v3i2.34609.  

 

 

 
RESEARCH ARTICLE 

 

EFFECT OF TRANSTIBIAL PROSTHESIS MASS ON GAIT ASYMMETRIES     

 
Seth M1*, Hou W2, Goyarts L.R1 , Galassi J.P1, Lamberg E.M1    
 

1 School of Health Technology and Management, Stony Brook University, Stony Brook, NY, USA. 

2 School of Medicine, Stony Brook University, Stony Brook, NY, USA. 

 
 
 
 

 

 

 

  

 

 

 

 

 

 

 

 

 

 
 

INTRODUCTION   

Individuals living with a transtibial amputation (TTA) 

typically present with an asymmetrical gait pattern 

characterized by a prolonged stance phase (temporal 

asymmetry)1-5 and greater loading on the intact side  

as compared to the prosthetic side (limb loading 

asymmetry).5-8 A prolonged asymmetrical gait may 

predispose the individual to poor health outcomes, such as, 

knee or hip osteoarthritis of the intact side,8,9 back pain,10 

and an increased risk of falling.11 Further, walking with an 

asymmetrical gait pattern may attract unwanted attention 

towards the individual.12 While, inherent factors associated 

with a TTA, such as weak prosthetic side push-off force 13 

and issues pertaining to load bearing of the residual limb,14 

may contribute to gait asymmetry, certain prosthetic factors, 

such as mass, may also contribute to gait asymmetry. 

Currently, the impact of prosthesis mass on gait asymmetry 

is not well defined. Further exploration may be vital to 

identifying any potential negative consequences that 

 
OPEN  ACCESS Volume 3, Issue 2, Article No.5. 2020 

 

 

Journal Homepage: https://jps.library.utoronto.ca/index.php/cpoj/index 

 

ABSTRACT 

BACKGROUND: Individuals with transtibial amputation (TTA) typically walk with an asymmetrical gait 

pattern, which may predispose them to secondary complications and increase risk of fall. Gait asymmetry 

may be influenced by prosthesis mass.  

OBJECTIVE: To explore the effects of prosthesis mass on temporal and limb loading asymmetry in 

people with TTA following seven days of acclimation and community use. 

METHODS: Eight individuals with transtibial amputation participated. A counterbalanced repeated 

measures study, involving three sessions (each one week apart) was conducted, during which three load 

conditions were examined: no load, light load and heavy load. The light load and heavy load conditions 

were achieved by adding 30% and 50% of the mass difference between legs, at a proximal location on 

the prosthesis. Kinematic and ground reaction force data was captured while walking one week after the 

added mass. Symmetry indices between the prosthetic and intact side were computed for temporal 

(Stance and Swing time) and limb loading measures (vertical ground reaction force Peak and Impulse). 

FINDINGS: Following seven days of acclimation, no significant differences were observed between the 

three mass conditions (no load, light load and heavy load) for temporal (Stance time: p=0.61; Swing time: 

p=0.13) and limb loading asymmetry (vertical ground reaction force Peak: p=0.95;  vertical ground 

reaction force Impulse: p=0.55). 

CONCLUSION: Prosthesis mass increase at a proximal location did not increase temporal and limb 

loading asymmetry during walking in individuals with TTA. Hence, mass increase subsequent to 

replacing proximally located prosthesis components may not increase gait asymmetry, thereby allowing 

more flexibility to the clinician for component selection. 

ARTICLE INFO 

Received: July 16, 2020 

Accepted: October 12, 2020 

Published: October 19, 2020 

CITATION 

Seth M, Hou W, Goyarts L.R, 

Galassi J.P, Lamberg E.M. 

Effect of transtibial prosthesis 

mass on gait asymmetries. 

Canadian Prosthetics & 

Orthotics Journal. 2020;Volume 

3, Issue 2, No.5. 

https://doi.org/10.33137/cpoj.v3i

2.34609 

KEYWORDS 

Prosthesis, Mass, Gait, Lower 

limb amputation, Kinematics,  

Kinetics, Ground reaction 

forces, Transtibial amputation, 

Gait asymmetry. 

 

* CORRESPONDING AUTHOR: 

Mayank Seth, PhD 
Delaware Limb Loss Studies Lab, University of Delaware, Newark, 
USA. 
E-mail: mseth@udel.edu 
ORCID: https://orcid.org/0000-0003-3526-7058 
 

https://doi.org/10.33137/cpoj.v3i2.34609
https://jps.library.utoronto.ca/index.php/cpoj/index
https://doi.org/10.33137/cpoj.v3i2.34609
https://doi.org/10.33137/cpoj.v3i2.34609
mailto:mseth@udel.edu
https://orcid.org/0000-0003-2933-4365
https://orcid.org/0000-0003-2933-4365


 

2 

Seth M, Hou W, Goyarts L.R, Galassi J.P, Lamberg E.M. Effect of transtibial prosthesis mass on gait asymmetries. Canadian Prosthetics & Orthotics Journal. 
2020;Volume 3, Issue 2, No.5. https://doi.org/10.33137/cpoj.v3i2.34609.  

ISSN: 2561-987X EFFECT OF TRANSTIBIAL PROSTHESIS MASS ON GAIT ASYMMETRIES     

Seth et al. 2020 

 
CPOJ 

 
prosthesis mass may have on gait asymmetry and by 

extension health outcomes, of adults with TTA. 

Previous efforts to determine the relationship between 

prosthesis mass and gait asymmetry have been completed, 

but only with limited application. In one mathematical study, 

it was theorized that temporal asymmetry seen in the gait of 

adults with lower limb amputation may be minimized by the 

achievement of inertial symmetry between the intact and 

prosthetic side.15 Other experimental and mathematical 

studies, however, found that matching prosthetic side mass 

completely (100%) with the intact side, through the addition 

of a distal load, produced an increase in temporal 

asymmetry.16-19 Thus, suggesting that a prosthesis should 

not be as heavy as the segment it replaces, particularly if 

mass is distributed more distally. However, the 

experimental evidence is limited regarding smaller 

prosthesis mass increments (<100%) and the application of 

mass at proximal locations. This would result in a prosthesis 

heavier than its original weight, but lighter in comparison to 

the intact side. Mass alterations at proximal locations are 

common clinically, subsequent to changing prosthesis 

components, i.e., socket, liner or socket/pylon interface 

adapters.  Hence, it is important to understand if these types 

of common increases in proximal prosthetic mass effect 

temporal asymmetry during walking.   

Further, the relationship between prosthesis mass and limb 

loading in people with TTA during walking has undergone 

limited exploration. Using a single subject design Hillary et 

al. examined the effects of increasing prosthesis mass by 

0.53kg and 1.46kg on limb loading in an adult with TTA.20 

The increase in prosthesis mass resulted in higher limb 

loading forces (1st vertical ground reaction force peak) on 

both the prosthetic and intact side.20 These increased 

impact forces are concerning as they may have 

consequences for bone and joint health.8,9 

Increasing prosthesis mass, through proximal load 

application, will make a prosthesis heavier, but may not 

always make the prosthetic side as heavy as the intact side 

(or 100% matching). Currently, it is unclear whether such 

mass increments to a prosthesis, i.e., less than 100% 

matching, will influence gait temporal and loading 

asymmetry of individuals with TTA. Further, the majority of 

current evidence on prosthesis mass is based on short 

acclimation periods prior to experimental data collection, 

which may yield differing results. The purpose of this study 

is to explore the effects of increasing prosthesis mass on 

temporal and limb loading asymmetry in people with TTA 

following seven days of acclimation and community use.  

METHODOLOGY 

A counterbalanced repeated measures study was 

conducted to examine the temporal and limb loading 

asymmetry in adults with TTA under three load conditions: 

original prosthesis mass with no load added (No load; NL), 

original prosthesis mass with 30% of the mass difference 

between prosthetic and intact side added (Light load; LL), 

and original prosthesis mass with 50% of the mass 

difference between prosthetic and intact side added (Heavy 

load; HL). The choice of the mass conditions was based on 

a pilot unpublished retrospective analysis of 12 medical 

charts of individuals with TTA. On an average, 30% (450g) 

and 50% (750g) of the mass difference between the 

prosthetic and intact side may represent the approximate 

mass change that may happen as a result of changing 

common prosthesis components.  

Participants 

Participants were included if they were male or female, 

between the ages of 18 to 70 years, had a unilateral 

amputation ≥ one year prior to participation and were 

community ambulators. Further, to minimize potential 

effects due to recent changes in prosthesis or any 

components, only individuals using their current prosthesis 

for at least three months were included. Potential 

participants were excluded if they had a health condition 

(cardiac, pulmonary, or musculoskeletal) limiting their ability 

to walk or if their prosthetic side was heavier than their intact 

side. Based on previous literature on this topic,16,17,19 the 

study was planned to enroll a minimum of 6 individuals with 

TTA. Informed written consent was obtained before 

participation. The study was approved by Stony Brook 

University’s Institutional Review Board.   

Limb mass properties 

Body mass (kg), height (m), residual limb and prosthesis 

measurements were ascertained. Prosthetic side mass 

(PSM) was calculated as the sum of prosthesis mass (with 

liner and shoe on a scale) and residual limb mass. To 

calculate residual limb mass, the residual limb was 

mathematically modeled as the frustum of a right circular 

cone using circumferential and length measurements as 

inputs and assuming a uniform tissue density of 

1.1gm/cm3.21 In order to calculate intact side mass, body 

mass (BM) needed to be adjusted to account for the 

amputated limb segment17:  

Equation 1: 𝐴𝐵𝑀 =
𝐵𝑀− 𝑃𝑆𝑀

(1−𝑐)
 

Where, BM is measured body mass while wearing the 

prosthesis, PSM is prosthetic side mass, and c is the 

amount of mass accounted by an intact shank and foot 

(0.057 for men and 0.061 for women).17 Then, using ABM 

the intact side shank and foot mass was calculated from 

standard limb segment mass estimates (5.7% for men and 

6.1% for women).22 In order to determine the load amount 

for each participant, the difference between prosthetic side 

and intact side mass was calculated and 30% (LL condition) 

and 50% (HL condition) of that difference was identified.  

https://doi.org/10.33137/cpoj.v3i2.34609


 

3 

Seth M, Hou W, Goyarts L.R, Galassi J.P, Lamberg E.M. Effect of transtibial prosthesis mass on gait asymmetries. Canadian Prosthetics & Orthotics Journal. 
2020;Volume 3, Issue 2, No.5. https://doi.org/10.33137/cpoj.v3i2.34609.  

ISSN: 2561-987X EFFECT OF TRANSTIBIAL PROSTHESIS MASS ON GAIT ASYMMETRIES     

Seth et al. 2020 

 
CPOJ 

 
Research protocol 

Participants attended three testing sessions scheduled one 

week apart (Figure 1), during which the load conditions (NL, 

LL and HL) were examined. During session one, study 

purpose and procedures were explained and the mass 

difference between limbs was calculated. Participants were 

then prepared for baseline data collection with their original 

prosthesis mass (NL). Following NL data collection, 

prosthesis mass was altered by adding either 30% (LL) or 

50% (HL) of the mass difference between limbs.  Mass was 

added circumferentially to the prosthesis socket at a 

proximal location that was 20 to 30% of the non-prosthetic 

side length. Flexible car wheel balancing weights (BADA 

steel tape-a-weight, Hennessey Industries LLC, LaVergne, 

TN, USA) were affixed at the desired location with one sided 

tape that was further held in place by wrapping Coban 

(3M™, Saint Paul, MN, USA) to prevent any loosening or 

slippage. The load sequence was altered between 

participants such that half received HL then LL and half 

received LL then HL. Once the mass was altered 

participants went home to use their prosthesis for seven 

days during their daily activities.   

 

Figure 1: Timeline of research sessions for one participant. The 

order of HL or LL was counterbalanced so that half received HL at 

session 1 then LL at session 2 and half received LL at session 1 

then HL at session 2. NL= No load, LL= Light load, HL= Heavy load. 

 

Data collection 

For all sessions, participants were prepared with the 

application of passive reflective markers over standardized 

anatomical landmarks on their pelvis and lower limbs using 

the modified Hellen Hayes marker set-up.23 On the 

prosthesis, markers were placed at locations corresponding 

to the intact side. Participants walked at their comfortable 

walking speed over a 10m walkway, while kinematic data 

was captured using a ten camera Vicon Motion System® 

(Oxford Metrics, Oxford, UK), recording at 100 Hz. In 

addition, ground reaction force (GRF) was captured through 

AMTI® force-plates (Watertown, USA) recording at 1000Hz.  

Data analysis 

Customized scripts developed in Matlab® (Mathworks, Inc.), 

were used to analyze and process the temporal and GRF 

data. Gait events (heel strike and toe off) were identified 

from the raw marker data extracted from Nexus VICON 

using the methodology proposed by Zeni et al.24 Temporal 

measures of stance time (heel strike to toe off) and swing 

time (toe off to heel strike) were determined for each leg. 

GRF data was processed using a zero-lag low-pass 4th 

order Butterworth filter, with a cutoff frequency of 20Hz.  

The beginning and end of stance phase for the vertical 

component of GRF (vGRF) was established using a vGRF 

threshold of 20N.25 The vGRF was normalized to each 

participant’s body mass (with prosthesis) and subsequently 

the maximum value during the 1st half of the stance phase 

was identified (vGRF Peak) and the area under the curve 

throughout the entire stance phase was calculated (vGRF 

Impulse).  

Symmetry indices (SI) for temporal and loading measures 

were calculated for each load condition26 where, I and P 

refer to intact and prosthetic side values. The SI ranges 

between 0 and 1, where 0 represents perfect symmetry. A 

positive SI indicates a higher value for the intact side: 

Equation 2: 𝑆𝐼 =  
(𝐼−𝑃)

(𝐼+𝑃)∗0.5
 

 

Statistics 

A single-factor repeated measures analysis of variance 

(ANOVA) was used to test for differences in SI for stance 

time, swing time, vGRF Peak and vGRF Impulse among the 

NL, LL, and HL conditions. An alpha level of 0.05 was used 

to evaluate significance.   

RESULTS 

Study Sample 

Eight male individuals with unilateral TTA who ambulate 

without assistive devices participated in this study (Table 1). 

Overall, 19 inquiries were received, and 14 individuals were 

screened over the phone. Of these 14, nine consented while 

five did not meet inclusion criteria or stated they did not want 

to add load to their device. Of the nine consented, one was 

subsequently excluded because the prosthetic side mass 

was higher than the intact side mass. Table 2 presents the 

mean of the calculated mass values.  

SESSION 1 

1) Informed consent 
2) Limb mass difference calculated 
3) Baseline data collection with NL 
4) Prosthesis mass altered to HL 

SESSION 2 

1) Data collection with HL 
2) Prosthesis mass altered to LL 

SESSION 3 

1) Data collection with LL 
2) Prosthesis mass returned to NL 

1-week acclimation 

1-week acclimation 

https://doi.org/10.33137/cpoj.v3i2.34609


 

4 

Seth M, Hou W, Goyarts L.R, Galassi J.P, Lamberg E.M. Effect of transtibial prosthesis mass on gait asymmetries. Canadian Prosthetics & Orthotics Journal. 
2020;Volume 3, Issue 2, No.5. https://doi.org/10.33137/cpoj.v3i2.34609.  

ISSN: 2561-987X EFFECT OF TRANSTIBIAL PROSTHESIS MASS ON GAIT ASYMMETRIES     

Seth et al. 2020 

 
CPOJ 

 
Table 1: Participant demographics and clinical characteristics. 

Participant 
Age  
(yrs) 

Body 
mass 
(kg)* 

Height  
(m) 

Time since 
amputation 

(yrs) 

Amputation 
etiology 

Side 

01 48 85.0 1.88 6 Infection Left 

02 29 101.0 1.72 4 Neurofibromatosis Left 

03 50 113.1 1.86 1 Trauma Left 

04 62 117.5 1.83 2 Vascular Right 

05 26 95.0 1.84 14 Cancer Left 

06 57 91.6 1.81 7 Trauma Left 

07 30 75.0 1.79 30 Congenital Right 

08 59 88.5 1.76 59 Congenital Right 

Mean 
(SD) 

45.1 
(14.7) 

95.8 
(14.2) 

1.81 
(0.05) 

15.4       
(20) 

- - 

 

* Body mass was measured with the prosthesis and shoe on the participant. 

 

Table 2: Estimated mass properties of the prosthetic and intact 

side. 

Measure Mean (SD) Range 

Adjusted body mass 96.9 (14.8) 75.4 – 119.5 

Non-prosthetic side mass 5.5 (0.8) 5.3 – 6.8 

Prosthetic side mass 4.5 (0.4) 3.9 – 5.2 

Mass difference between sides 1.0 (0.7) 0.4 – 2.3 

Load 
conditions 

Light Load (30% of 
difference) 

0.3 (0.2) 0.1 – 0.7 

Heavy Load (50% of 
difference) 

0.5 (0.3) 0.2 – 1.1 

 

All values in kg. Non-prosthetic side mass refers to estimated shank and foot 

mass of non-prosthetic side. Prosthetic side mass refers to the sum of 

estimated residual limb mass and prosthesis mass (with shoe, liner and 

suspension system). 

Main results  

The mean (SD) for stance time, swing time, vGRF Peak and 

vGRF Impulse on the prosthetic and intact side with the 

three load conditions (NL, LL and HL) and the SI are 

presented in Table 3. The mean (SD) stance time SI and 

swing time SI for the three load conditions is also presented 

in Figure 2. The mean vGRF profile of the participants for the 

prosthetic and intact side with the three load conditions (NL, 

LL and HL) is presented in Figure 3.   

Following seven days of acclimation, increasing the mass of 

the prosthesis by 30% and 50% did not significantly affect 

the SI values between the prosthetic and intact side for 

temporal (Stance time: p=0.61; swing time: p=0.13) and 

loading measures (vGRF Peak: p=0.95; vGRF Impulse: 

p=0.55). 

 
Figure 2: Mean stance time SI (A) and swing time SI (B) across the 

three load conditions. Error bars represent 1 SD. Negative SI 

values indicate that intact side values were higher. NL= No load, 
LL= Light load, HL= Heavy load.    

 

Table 3: Mean (SD) temporal and GRF measures for the three load conditions. NL= No load, LL= Light load, HL= Heavy load. 

 NL LL HL Sig. 
(p-value)  P NP SI% P NP SI% P NP SI% 

Stance time (secs) 
0.77 

(0.04) 
0.80  

(0.05) 
3.49%  
(3.79) 

0.79  
(0.04) 

0.80  
(0.05) 

2.15%  
(2.77) 

0.76 
 (0.05) 

0.78  
(0.05) 

2.69% 
(2.23) 

0.61 

Swing time (secs) 
0.40 

(0.03) 
0.39  

(0.02) 
-3.32%  
(5.23) 

0.41  
(0.01) 

0.39 
(0.02) 

-4.46% 
(5.16) 

0.40  
(0.02) 

0.39 
(0.02) 

-1.91%  
(5.86) 

0.13 

vGRF Peak (BM) 
1.03 

(0.07) 
1.14  

(0.12) 
9.70%  
(10.70) 

1.05  
(0.07) 

1.15  
(0.07) 

9.06%  
(6.20) 

1.06  
(0.08) 

1.16  
(0.09) 

9.51% 
(9.35) 

0.95 

vGRF Impulse (BM) 
0.56 

(0.04) 
0.60  

(0.04) 
7.99%  
(7.11) 

0.57  
(0.03) 

0.61  
(0.04) 

6.89% 
(6.32) 

0.56  
(0.04) 

0.60  
(0.03) 

6.73%  
(7.53) 

0.55 

P: mean (SD) raw score for the prosthetic side; NP: mean (SD) raw score for the non-prosthetic side; SI%: symmetry index % between the prosthetic and non-

prosthetic side; BM: normalized to body mass. The p-values between the three load conditions are for the SI% 

3.49%

2.15% 2.69%

0%

2%

4%

6%

8%

NL LL HL

Stance time SIA

-3.32%
-4.46%

-1.91%
-11%

-7%

-3%

NL LL HL

Swing time SI

B 

https://doi.org/10.33137/cpoj.v3i2.34609


 

5 

Seth M, Hou W, Goyarts L.R, Galassi J.P, Lamberg E.M. Effect of transtibial prosthesis mass on gait asymmetries. Canadian Prosthetics & Orthotics Journal. 
2020;Volume 3, Issue 2, No.5. https://doi.org/10.33137/cpoj.v3i2.34609.  

ISSN: 2561-987X EFFECT OF TRANSTIBIAL PROSTHESIS MASS ON GAIT ASYMMETRIES     

Seth et al. 2020 

 
CPOJ 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 3: Mean normalized vGRF activity of the prosthetic (A) and 
intact side (B) across the three load conditions (NL, LL and HL). 

The shaded region represents 1±SD of the group mean27 for that 

load condition. NL= No load, LL= Light load, HL= Heavy load. 

 

DISCUSSION  

This study explored the impact of increasing prosthesis 

mass on temporal and limb loading asymmetry in people 

with TTA following seven days of acclimation and 

community use. According to the findings, increasing 

prosthesis mass by either 30% or 50% of the mass 

difference between legs did not significantly alter temporal 

and limb loading asymmetry. These findings imply that a 

range of prosthesis mass may exist for this population. This 

ultimately may allow clinicians flexibility when choosing 

prosthesis components knowing that increasing mass within 

this range may not negatively impact gait asymmetries.  

Temporal asymmetry 

Literature on transtibial prosthesis mass has largely focused 

on examining temporal asymmetry during walking.15-19 

Perhaps the proposed association between limb inertia and 

swing time or the secondary complications as a result of an 

asymmetrical gait, necessitate the examination of temporal 

measures following mass alterations. In this study, stance 

and swing time asymmetries were not significantly affected 

as a result of the mass alteration. Previous studies 

examining stance and swing time asymmetries have found 

that matching prosthetic side mass to the intact side (100% 

load condition) increases asymmetry.16-19 The same 

however, is not true for partial matching (50% load 

condition). Similar to the findings of the current study, Smith 

and Martin report no effect of the 50% load condition on 

stance and swing time asymmetry.17 However, Mattes et al. 

observed a significant increase in temporal asymmetry with 

the 50% load condition.16 Hence, Mattes et al., observed a 

linear response to the mass increase; as prosthesis mass 

increased, stance time on the intact side and swing time on 

the prosthetic side increased, thereby increasing limb 

temporal asymmetry.16 Interestingly, Mattes et al., used a 

similar approach as the current study to estimate mass 

difference between limbs. However, they achieved the 50% 

condition by adding an average load of 0.85kgs,16  while this 

study used an average of 0.54kgs, which may partially 

explain the divergence in findings. Perhaps the key 

difference between the studies is the length of acclimation 

period used, ten minutes by Mattes et al.,16 versus one week 

in this study. The longer acclimation time provided in this 

study may have allowed participants to stabilize their gait, 

leading to the lack of statistically significant findings. 

Although, in previous research it has been observed that 

stance and swing time asymmetries (as a result of the 100% 

load condition) persisted even after eight days of 

acclimation19; this finding, doesn’t necessarily rule out the 

importance of acclimation. It is more likely that individuals 

with TTA are not well suited to carry a prosthesis that 

weighs as much as the amputated segment.  

Limb loading asymmetry 

Limb loading asymmetry (measured using vGRF Peak and 

vGRF Impulse SI), was not affected as a result of the mass 

increase, i.e., no differences were observed between the 

three load conditions (NL, LL and HL). The positive SI 

values (Table 3) indicate that participants in this study 

loaded their intact side more than the prosthetic side, 

consistent with previous findings in the literature.5-8 The 

addition of load, however, did not significantly change the 

proportion of loading experienced by the intact side.  

Prosthetic side 

% Gait cycle 

Intact side 

N
o

rm
a
li
z
e
d

 v
G

R
F
 

N
o

rm
a
li
z
e
d

 v
G

R
F
 

% Gait cycle 

https://doi.org/10.33137/cpoj.v3i2.34609


 

6 

Seth M, Hou W, Goyarts L.R, Galassi J.P, Lamberg E.M. Effect of transtibial prosthesis mass on gait asymmetries. Canadian Prosthetics & Orthotics Journal. 
2020;Volume 3, Issue 2, No.5. https://doi.org/10.33137/cpoj.v3i2.34609.  

ISSN: 2561-987X EFFECT OF TRANSTIBIAL PROSTHESIS MASS ON GAIT ASYMMETRIES     

Seth et al. 2020 

 
CPOJ 

 
In the single subject case study by Hillery et al., the authors 

observed an increase in loading (vGRF Peak) on the 

prosthetic and the intact side with an increase in prosthesis 

mass.20 Based on the SI equation,26 it appears that the 

study participant’s loading asymmetry increased from 5.4% 

at baseline to 12% with the intermediate load (0.5kgs) and 

21% with the heaviest load (1.5kgs).20 In contrast, vGRF 

Peak SI in the current study changed from an average of 

9.70% at baseline to 9.1% with LL (0.3kgs) and 9.5% with 

the heaviest load condition, HL (0.5kg). This difference in 

findings may be due to the heavier loads used by Hillery et 

al., or perhaps the longer acclimation period given in the 

current study allowed users to stabilize their gait before data 

was collected. However, given the single-subject study 

design by Hillery et al., their findings may not be generalized 

to a larger group.20    

In a more recent study of a group of active adults with TTA 

(n=10), Alcantara et al. examined the impact of increasing 

the mass of a running-specific prosthesis and biological foot 

on participants’ limb loading asymmetry during running.28 

Prosthesis and biological foot mass were increased by 

adding 100g or 300g at the toe region. The mass increase, 

however, did not result in any significant change to limb 

loading asymmetry (vGRF peak SI or average-stance vGRF 

SI) as compared to baseline, regardless of added load 

(100g or 300g) or whether mass was added to the 

prosthesis or both limbs.28 Obvious differences exist 

between Alcantara et al., and the current study, such as the 

location of mass addition or their use of a running task. 

However, collectively, these findings suggest that small 

increases in prosthesis mass may not contribute to the limb 

loading asymmetry and by extension lower health outcomes 

generally associated with asymmetrical limb loading, such 

as knee or hip osteoarthritis of the intact side.  

The need to change a prosthesis component or replace a 

prosthesis completely may arise due to various personal 

and/or clinical reasons. Such changes may increase or 

decrease the overall prosthesis mass. For example, the 

replacement of prefabricated transtibial gel liners, which 

range from 202g to 722g, may alter prosthesis mass.29 

Findings from this study suggest that the mass increments 

similar to those observed after replacing proximally located 

prosthesis components (such as, the socket, liners, or 

socket/pylon interface adapters), may not increase gait 

asymmetry. These findings are clinically relevant as they 

may serve as a guide for clinicians when routinely adjusting 

prosthesis mass. However, to further identify the impact of 

prosthesis mass on gait asymmetry, it is vital that future 

large-scale studies explore the impact of various 

commercially available prosthesis components and related 

functional and clinical outcomes. Moreover, future studies 

may consider controlling other factors that may influence 

gait characteristics of an individual, for example, residual 

limb length, quality and type of suspension between the 

prosthesis and residual limb, or exertion of the individual 

during a walking task. 

Study limitations 

The current study was limited both by a small sample size 

(n=8), and a male-only participant group. It is possible that 

the small sample size may not have had sufficient power to 

detect a significant change. Moreover, in order to make 

stronger conclusions on prosthesis mass, it remains 

necessary to evaluate both men and women with TTA. As 

part of the inclusion criteria, only individuals that were 

capable of independent ambulation were included within the 

study. Therefore, the current findings may not extend to 

individuals with TTA who exhibit lower levels of activity. 

Further, this study chose to limit mass increase to 50% of 

the mass difference between both limbs. To establish the 

upper limit of a TTP mass it may be necessary to evaluate 

heavier loads. Lastly, certain covariates, such as, residual 

limb length, quality and type of suspension between the 

prosthesis and residual limb or prosthesis componentry 

may have impacted both gait asymmetry and prosthesis 

mass of the study participants but were not controlled in this 

study.  

CONCLUSION 

Temporal and loading asymmetries during walking in 

people with TTA may lead to secondary complications of the 

intact side and increase risk of falls. Currently, it is unclear 

if prosthesis mass alterations that may occur during routine 

clinical visits will impact these gait asymmetries. This 

exploratory study observed that following seven days of use 

increases in proximally distributed prosthesis mass (up to 

50% of the mass difference between legs), did not further 

increase temporal and limb loading asymmetry of 

individuals with TTA, thereby allowing more flexibility to the 

clinician for component selection. Confirmation of findings 

with large-scale studies may help identify the impact of 

prosthesis mass on gait asymmetry. 

ACKNOWLEDGEMENTS 

We would like to acknowledge study participants for their 

contribution towards this research study. 

DECLARATION OF CONFLICTING 

INTERESTS 

The authors have no conflicts of interests to declare.  

AUTHOR CONTRIBUTION 

Mayank Seth: Study conceptualization, analysis, data collection, 

data interpretation and writing - original draft 

Wei Hou: Assisted in study design, led statistical analysis, writing - 

review & editing 

https://doi.org/10.33137/cpoj.v3i2.34609


 

7 

Seth M, Hou W, Goyarts L.R, Galassi J.P, Lamberg E.M. Effect of transtibial prosthesis mass on gait asymmetries. Canadian Prosthetics & Orthotics Journal. 
2020;Volume 3, Issue 2, No.5. https://doi.org/10.33137/cpoj.v3i2.34609.  

ISSN: 2561-987X EFFECT OF TRANSTIBIAL PROSTHESIS MASS ON GAIT ASYMMETRIES     

Seth et al. 2020 

 
CPOJ 

 
Laura R Goyarts: Assisted in data collection, writing - review & 

editing 

James P Galassi: Assisted in data collection, writing - review & 

editing 

Eric M Lamberg: Study conceptualization, project administration, 

supervision, data interpretation, writing – review & editing 

SOURCES OF SUPPORT 

This research did not receive any specific grant from funding 

agencies in the public, commercial or not-for-profit sectors. 

ETHICAL APPROVAL 

The study was approved by Stony Brook University’s Institutional 

Review Board.   

REFERENCES 

1.Dingwell JB, Davis BL, Frazier DM. Use of an instrumented 

treadmill for real-time gait symmetry evaluation and feedback in 

normal and trans-tibial amputee subjects. Prosthet Orthot Int. 

1996;20(2):101-10. DOI: 10.3109/03093649609164426 

2.Nolan L, Lees A. The functional demands on the intact limb during 

walking for active transfemoral and transtibial amputees. Prosthet 

Orthot Int. 2000;24(2):117-25. DOI: 10.1080/03093640008726534 

3.Nolan L, Wit A, Dudzinski K, Lees A, Lake M, Wychowanski M. 

Adjustments in gait symmetry with walking speed in trans-femoral 

and trans-tibial amputees. Gait Posture. 2003;17(2):142-51. DOI: 

10.1016/s0966-6362(02)00066-8 

4.Sanderson DJ, Martin PE. Lower extremity kinematic and kinetic 

adaptations in unilateral below-knee amputees during walking. Gait 

Posture. 1997;6(2):126-36. DOI:10.1016/S0966-6362(97)01112-0 

5.Cutti AG, Verni G, Migliore GL, Amoresano A, Raggi M. 

Reference values for gait temporal and loading symmetry of lower-

limb amputees can help in refocusing rehabilitation targets. J 

Neuroeng Rehabil. 2018;15(1):61. DOI: 10.1186/s12984-018-

0403-x 

6.Engsberg J, Lee A, Tedford K, Harder J. Normative ground 

reaction force data for able-bodied and trans-tibial amputee 

children during running. Prosthet Orthot Int. 1993;17(2):83-9. DOI: 

10.3109/03093649309164361 

7.Powers CM, Torburn L, Perry J, Ayyappa E. Influence of 

prosthetic foot design on sound limb loading in adults with unilateral 

below-knee amputations. Arch Phys Med Rehabil. 1994;75(7):825-

9. DOI: 10.1016/0003-9993(94)90146-5 

8.Gailey R, Allen K, Castles J, Kucharik J, Roeder M. Review of 

secondary physical conditions associated with lower-limb 

amputation and long-term prosthesis use. J. Rehabil. Res. Dev. 

2008;45(1). DOI: 10.1682/JRRD.2006.11.0147 

9.Kulkarni J, Adams J, Thomas E, Silman A. Association between 

amputation, arthritis and osteopenia in British male war veterans 

with major lower limb amputations. Clin Rehabil. 1998;12(4):348-

53. DOI: 10.1191/026921598672393611 

10.Esposito ER, Wilken JM. The relationship between pelvis–trunk 

coordination and low back pain in individuals with transfemoral 

amputations. Gait posture. 2014;40(4):640-6. DOI: 10.1016/ 

j.gaitpost.2014.07.019 

11.Vanicek N, Strike S, McNaughton L, Polman R. Gait patterns in 

transtibial amputee fallers vs. non-fallers: Biomechanical 

differences during level walking. Gait Posture. 2009;29(3):415-20. 
DOI: 10.1016/j.gaitpost.2008.10.062 

12.Handžić I, Reed KB. Perception of gait patterns that deviate from 

normal and symmetric biped locomotion. Front. Psychol. 

2015;6:199. DOI: 10.3389/fpsyg.2015.00199 

13.Adamczyk PG, Kuo AD. Mechanisms of Gait Asymmetry Due to 

Push-Off Deficiency in Unilateral Amputees. IEEE Trans Neural 

Syst Rehabil Eng. 2015;23(5):776-85. DOI: 10.1109/TNSRE. 

2014.2356722 

14.Silver-Thorn B, Steege JW, Childress DS. A review of prosthetic 

interface stress investigations. J. Rehabil. Res. Dev. 1996. 

15.Mena D, Mansour J, Simon S. Analysis and synthesis of human 

swing leg motion during gait and its clinical applications. J Biomech. 

1981;14(12):823-32DOI:10.1016/0021-9290(81)90010-5 

16.Mattes SJ, Martin PE, Royer TD. Walking symmetry and energy 

cost in persons with unilateral transtibial amputations: matching 

prosthetic and intact limb inertial properties. Arch Phys Med 

Rehabil. 2000;81(5):561-8. DOI: 10.1016/S0003-9993(00)90035-2 

17.Smith JD, Martin PE. Effects of prosthetic mass distribution on 

metabolic costs and walking symmetry. J Appl Biomech. 

2013;29(3):317-28. DOI: 10.1123/jab.29.3.317 

18.Selles RW, Korteland S, Van Soest A, Bussmann JB, Stam HJ. 

Lower-leg inertial properties in transtibial amputees and control 

subjects and their influence on the swing phase during gait. Arch 

Phys Med Rehabil. 2003;84(4):569-77. DOI: 10.1053/apmr. 

2003.50037 

19.Smith JD, Martin PE. Short and longer term changes in amputee 

walking patterns due to increased prosthesis inertia. J Prosthet 

Orthot. 2011;23(3):114-23. DOI: 10.1097/JPO.0b013e3182248d90 

20.Hillery S, Wallace E, McIlhagger R, Watson P. The effect of 

changing the inertia of a trans-tibial dynamic elastic response 

prosthesis on the kinematics and ground reaction force patterns. 

Prosthet Orthot Int. 1997;21(2):114-23. DOI: 10.3109/ 

03093649709164539 

21.Hanavan EL. A Mathematical Model of the Human Body. AMRL-

TR-64-102, AD-608-463. Ohio: Aerospace Medical Research 

Laboratory, Wright-Patterson Air Force Base. 1964. 

22.De Leva P. Adjustments to Zatsiorsky-Seluyanov's segment 

inertia parameters. J Biomech. 1996;29(9):1223-30. DOI:10.1016/ 

0021-9290(95)00178-6 

23.Kadaba MP, Ramakrishnan HK, Wootten ME. Measurement of 

lower extremity kinematics during level walking. J Orthop Res. 

1990;8(3):383-92. DOI: 10.1002/jor.1100080310 

24.Zeni Jr J, Richards J, Higginson J. Two simple methods for 

determining gait events during treadmill and overground walking 

using kinematic data. Gait posture. 2008;27(4):710-4. DOI: 

10.1016/j.gaitpost.2007.07.007 

25.Rueda FM, Diego IMA, Sánchez AM, Tejada MC, Montero FMR, 

Page JCM. Knee and hip internal moments and upper-body 

kinematics in the frontal plane in unilateral transtibial amputees. 

Gait Posture. 2013;37(3):436-9. DOI: 10.1016/j.gaitpost.2012. 

08.019 

https://doi.org/10.33137/cpoj.v3i2.34609


 

8 

Seth M, Hou W, Goyarts L.R, Galassi J.P, Lamberg E.M. Effect of transtibial prosthesis mass on gait asymmetries. Canadian Prosthetics & Orthotics Journal. 
2020;Volume 3, Issue 2, No.5. https://doi.org/10.33137/cpoj.v3i2.34609.  

ISSN: 2561-987X EFFECT OF TRANSTIBIAL PROSTHESIS MASS ON GAIT ASYMMETRIES     

Seth et al. 2020 

 
CPOJ 

 
26.Robinson RO, Herzog W, Nigg BM. Use of force platform 

variables to quantify the effects of chiropractic manipulation on gait 

symmetry. J Manipulative Physiol Ther. 1987;10(4):172-6. 

27.Musall S. stdshade MATLAB Central File Exchange 2010 

Available from: https://www.mathworks.com/matlabcentral/ 

fileexchange/29534-stdshade. 

28.Alcantara RS, Beck ON, Grabowski AM. Added lower limb mass 

does not affect biomechanical asymmetry but increases metabolic 

power in runners with a unilateral transtibial amputation. Eur J Appl 

Physiol. 2020;120(6):1449-56. DOI: 10.1007/s00421-020-04367-9 

29. Selinger D. Weight of Prefabricated Transtibial Gel Prosthetic 

Liners A Standardized Sample. Resident Research Project. 

California State University, Dominguez Hills. 2004. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

https://doi.org/10.33137/cpoj.v3i2.34609

