The spatiotemporal gait parameters among people with visual impairment: A literature review study

Abstract

Gait is an individual's walking pattern, and it is a significant part of daily living activities. Quantitative gait assessments, like spatiotemporal parameters (STPs), are related to the functional conditions to provide useful information. This study reviewed the comprehensive differences in spatiotemporal gait variability measures between visually impaired people and the sighted. The search strategy was performed in three databases (PubMed/MEDLINE, Web of Science, and Scopus) from the start date to October 2022, and the utilized keywords for this search are related to gait and blindness. This review considered only those studies that evaluated gait parameters in people with visual impairment and blind people without any limitations in age and gender. In this review, studies without a control group (sighted people) were excluded. The Newcastle–Ottawa Scale (NOS) was applied for critical appraisal. Six full manuscripts were included. The sample size ranged from 19 to 91. The mean modified NOS critical appraisal scores for cross-sectional studies were 6.0. In these studies, among nine STPs: stride length, walking speed, stance and swing phase, step width, cadence, step length, double support, and single support, at least five and at most seven factors were examined. The gait pattern of blind and low-vision people is characterized by a slower walking speed, shorter stride length, increased step width, decreased cadence, prolonged duration of double support, and reduced single support compared to the controls.

Introduction

Human walking is the most common type of locomotion, with interaction between different systems in the body.[1] Gait, the scientific term used to describe the pattern of human walking, is simple in execution, but complicated in terms of motor control and biomechanics.[2] A gait cycle is a period of repetitive events during locomotion, in which one foot contacts the ground to when that the same foot again contacts the floor and involves propulsion of the center of mass in the direction of movement. A single gait cycle is also known as a stride.[3]

Quantitative and qualitative assessments of gait are an effective tool to better understand the mechanisms of a gait disorder and guide choosing the practical intervention. Abnormal gait can cause falling and decreased mobility, with significant health consequences.[4]

The objective measures of gait's temporal and spatial parameters enable defining the level of impairment and characterizing functional gait performance, which can be used as a mobility biomarker. The most commonly used temporal gait parameters include stride time (s), swing phase (%), stance phase (%), double support (%), and cadence (step/min). In addition, spatial gait parameters include step length (m), velocity (m/s), stride length (m), and step width (m).[5,6]

Vision is a primary source of stimulus that enables direct interaction with the surroundings.

Exploring the environment and walking, especially in children, is associated with gaining important experiences and allows the individual to grow and adapt to the environment.[7] Worldwide, there are a minimum of 2.2 billion people with visual impairments.[8] Gait disorders are common in individuals with visual impairment or blindness, increasing the risk of accidental falling and physical disability.[5,9] The studies show that gait in visually impaired people is different from healthy sighted people.[6,10] Nakamura reported a gait analysis of visually impaired persons showing generally slower walking speed, shorter stride length, and longer stance time.[10] In 2010, Hallemans et al. carried out a gait analysis to examine the spatiotemporal factors of some visually impaired adults. In this study, the participants, some of whom were totally blind, were supposed to walk on even terrain. Compared to the control group (who had normal visual abilities), the findings indicated that the experimental group had a shorter stride length, and there was no difference between the two groups’ preferred walking speed.[11]

To the researchers’ knowledge, a literature review has been conducted to date on an individual's gait with visual impairment. Furthermore, this article did not specify which one of the gait factors was considered.[12] To find the study articles, researchers searched the EBSCOhost, academic Google, and PubMed databases. The study's objective was more comprehensive to review the differences in spatiotemporal gait variability measures between people with visual impairment and sighted people.

Methods

To provide a comprehensive overview of gait, this review considered those articles that utilized studies that evaluated gait parameters among people with visual impairment and blind people without any limitations on age and gender. Studies without a control group (sighted people) were excluded from the research. No language restrictions apply to searches. The articles that reach the selection stage are translated by Google Translate and reevaluated by official translators for the definitive selection. The search strategy followed the steps of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flow diagram. The databases searched were PubMed/MEDLINE, Web of Science, and Scopus. Two independent evaluators conducted a literature search from the start date to October 2022.

The search terms used were synonymous with gait and spatiotemporal parameters (STPs) obtained through the MeSH – PubMed database, key terms in pilot articles, and expert opinion. The utilized keywords for this search were related to gait, including gait, biped gait, gait analysis, gait training, pattern, walking, walking pattern, walking speed, gait variability, spatiotemporal, step length, stride length, step width, step time, stride time, stance time, swing time, single-support time, double-support time, walk, locomote, ambulatory, and mobility; cadence, speed, and words related to blindness inclusive: blind, blinding, blindness, visual disorder, vision disorders, blind person, blind people, visual deprivation, visual impairment, vision impairment, vision impaired, impaired vision, sight impairment, vision defect, vision loss, visual loss, visual handicap, amaurosis, no light perception, absence of vision, and congenital blindness. The selected keywords were separated using “OR,” “AND,” and “NOT.” An example of a search strategy used in databases is contained in Appendix 1.

The Newcastle–Ottawa Scale (NOS) was applied for critical appraisal. This scale uses the following domains to assess the quality of the study: selection, comparability, and ascertainment of outcome.[13] The studies were rated on a scale from 0 to 10, with higher ratings indicating better quality. Based on the NOS score standard, cross-sectional studies can be divided into low quality (scores of 0–4), medium quality (scores of 5–6), and high quality (scores ≥7).[14]

Results

The PRISMA flow diagram [Figure 1] shows the results for each selection stage. The literature search identified a total of 3131 articles on databases. After selection, six articles were included in the synthesis. Selected articles were reviewed and summarized in Table 1 based on: the name of Author (year of publication), Study type, Age range, Instrument, the number of participants and the spatiotemporal gait parameters. In these studies, walking speed, stride length (m), step length (m), stance and swing phase (%), step width (m), cadence (step/min), double support, and single support (%) were determined as the spatiotemporal gait parameters of visually impaired people. In all this research, a motion analysis system has been used to analyze the gait patterns of visually impaired and sighted people. However, the number of cameras and motion analysis systems was different.

Figure 1.

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses flow diagram of the study

Table 1.

Characteristics of the studies included in the review

Author (year)	Study type	Age range (year)	Instrument	Sample size	Spatial-temporal gait parameter (mean±SD)
					Speed (m/s)	Stride length (m)
Nakamura (1997)[10]	Comparative	36–50 male	Motion analysis system	Late blind (15)	1.11±0.13b,h	1.06±0.11b,h
				Congenitally (15)	0.86±0.09b,h	0.96±0.08b,h
				Normal vision (15)	1.50±0.08b	1.23±0.04b
Hallemans et al. (2010)[11]	A cross-sectional study	14–39.5 Male and female	Vicon Mcam 60	Visual impairment (10)	1.09±0.25	1.14±0.21b
				Normal vision (20)
				Eye open	1.27±0.13a	1.36±0.08a,b
				Eye close	0.84±0.28a	1.02±0.25a
Gazzellini et al. (2016)[15]	A cross-sectional study	3.5–13.2 Male	Vicon MX	Congenital (12)	0.82±0.27b	-
				Normal vision (11)	1.14±0.24b	-
Caroline Cunha do Espírito Santo et al. (2018)[16]	Comparative and cross-sectional research	22–34 Male and female	Video camera of 60 Hz	Total blindness (8)	0.65±0.18b	0.83±0.16b
				Normal vision (11)	1.32±0.19b	1.32±0.12b
Hallemans et al. (2011)[5]	A cross-sectional cohort study	1–46 Male and female	Vicon, Oxford	Visual impairment (31)
				Blind (9)	0.262±0.118d	1.014±0.331d
				Low vision (22)	0.422±0.119d	1.425±0.258d,e
				Normal vision (60)	0.456±0.067d	1.572±0.159d,e
Majlesi et al. (2020)[6]	A cross-sectional study	19–30 Male	Vicon, Oxford	Congenital (10)	0.97±0.06b	1.07±0.06b,y
				Normal vision (10)
				Eye open	1.24±0.06b	1.36±0.06b
				Eye close	1.13±0.07	1.36±0.07y
Author (year)	Spatial-temporal gait parameter (mean±SD)
	Step length (m)	Stance (%)	Swing (%)	Step width (m)	Cadence (step/min)	Double support (%)	Single support (%)
Nakamura (1997[10]		60.58±1.92b,h	39.42±1.92	-	-	-	-
	-	62.04±2.77b,h	37.96±2.77	-	-	-	-
	-	59.60±2.02b	40.40±2.02	-	-	-	-
Hallemans et al. (2010)[11]	-	61.81±3.03	-		113.81±11.53y	-	-
	-	61.26±1.56	-	-	110.55±7.09a	-	-
	-	63.03±7.57	-	-	96.88±13.7a,y	-	-
Gazzellini et al. (2016)[15]	0.39±0.13b	-	-	0.18±0.05b	-	23.2±5.8b	38.9±4.3b
	0.56±0.11b	-	-	0.12±0.04b	-	17.7±3.5b	42.2±6b
Caroline Cunha et al. (2018)[16]	-	34.3±2.25b	65.7±1.08b	-	135±0.27b	14±1.08b	-
	-	39.0±1.36b	61.0±1.87b	-	169.2±0.18b	10±1.87b	-
Hallemans et al. (2011)[5]	-	56.89±14.55d	-	0.258±0.151	-	28.99±18.75g	-
	-	62.84±4.01d	-	0.217±0.084	-	24.80±8.03g	-
	-	59.61±2.18d	-	0.182±0.057	-	18.82±3.94g	-
Majlesi et al. (2020)[6]	0.54±0.03b,y	61.6%±2.67	38.4±1.78	-	-	38.57±2.85	61.42±2.85
	0.68±0.03b	63.06±2.70	36.93±1.80a	-	-	41.42±2.85	58.57±2.85a
	0.69±0.04y	60.97±2.43	39.03±1.62a	-	-	36±2.66	64±2.66a

^aSignificant difference between eyes open and eyes closed in the control group, ^bSignificant difference between eyes open in the control group and experimental group, ^ySignificant difference between close–open in the control group and experimental group, ^dSignificant difference between blind individuals compared to both controls and the low-vision group, ^eSignificant difference between controls and the low-vision group, ^gSignificant difference between control group compared to both blind and the low-vision groups, ^hSignificant difference between late and congenitally blind. Statistically significant at P <0.05. SD: Standard deviation

Critical appraisal (quality assessment)

The mean modified NOS critical appraisal scores for cross-sectional studies were 6.0 (maximum of 10). Of the six studies, five studies were assessed to be of moderate quality (scores of 5–6). One study was considered to be of high quality [Table 2].

Table 2.

Critical appraisal of the studies by the Newcastle–Ottawa Scale

Study	Selection
	Representativeness of the sample	Sample size	Comparability of nonrespondents	Ascertainment of the exposure
Nakamura (1997)[10]	-	-	-	-
Hallemans et al. (2010)[11]	-	-	-	*
Gazzellini et al. (2016)[15]	-	-	*	*
Caroline Cunha et al. (2018)[16]	-	-	-	*
Hallemans et al. (2011)[5]	-	-	-	*
Majlesi et al. (2020)[6]	-	-	-	*
Study	Comparability	Outcome		Quality score
	Statistical analysis design features	Assessment of outcome	Statistical test
Nakamura (1997)[10]	**	**	*	Satisfactory (5)
Hallemans et al. (2010)[11]	**	**	*	Satisfactory (6)
Gazzellini et al. (2016)[15]	**	**	*	Good (7)
Caroline Cunha et al. (2018)[16]	**	**	*	Satisfactory (6)
Hallemans et al. (2011)[5]	**	**	*	Satisfactory (6)
Majlesi et al. (2020)[6]	**	**	*	Satisfactory (6)

*A study can be awarded a maximum of one star for each numbered item within the Selection and Exposure categories, **A maximum of two stars can be given for Comparability, No stars are assigned to that item

The parameters examined in the studies included in the review [Table 1] are presented in detail below.

Walking speed (meter per second)

The walking speed is the time a person walks on a smooth surface for a specified and short distance.[3] Among the six studies, all examined the walking speed, and five studies showed a significant reduction in the speed of blind and low-vision people compared to the control group.[5,6,10,11,15,16] For normal-vision people, the walking speed range was 0.45–1.50 m/s, whereas the speed of blind and low-vision people was 0.26–1.11 m/s.[5,6,10,15,16]

Stride length (meter)

The distance between heel strikes of one limb and the subsequent heel strike is stride length. In this way, a stride continually consists of the left and right steps.[3] Five studies analyzed stride length among visual impairment and normal-vision people.[5,6,10,11,16] The decrease in this parameter was reported in studies and was significant. For blind and visually impaired individuals, the stride length range was 0.83–1.42 m, whereas the stride lengths of normal-vision people were 1.32–1.57 m.[5,6,10,11,16]

Step length (meter)

The step is regularly used in the description of gait. The initial contact of one foot to the next initial contact of another foot is defined as a step.[3] Interestingly, only two studies assessed step length among congenital visual impairment people and the control group.[6,15]

In Gazzellini et al. and Majlesi et al.'s studies, the analysis of single gait parameters revealed that the congenitally blind presented reduced step length compared to the control group. In these studies, significant differences were observed in the step length.[6,15]

For congenital vision loss, the step lengths range was 0.39–0.54 m, whereas this parameter for sighted individuals was 0.56–0.69 m.[6,15]

Step width (meter)

The side-to-side distance between the heels, usually measured from the center of the ankle joint, is defined as step width.[3] Two studies have assessed the changes in step width between people with visual impairment and sighted people.[5,15] Gazzellini et al. and Hallemans et al. reported that visual impairment people walk with wider steps than the control group during walking.[5,15]

Cadence (step/minute)

Cadence is defined based on the number of steps taken per minute.[3] Only two studies have evaluated cadence in visual impairment individuals during walking.[11,16] The study found a significant reduction in gait parameters like cadence in visually impaired individuals.

Stance and swing time (second)

Swing time is the period when the lower extremity in question is not in contact with the ground.[17] This phase usually accounts for 40% of the duration of a complete cycle. Stance time is defined as the period when the lower limb is in contact with the ground, providing support for the body.[3] The stance phase is approximately 60% of the duration of one complete cycle.[18] Five studies have examined the mean stance phase between sighted and visually impaired people, which was significant in three studies.[5,6,10,11,16] It was obtained in the range of 0.34–0.63 s for blind people, and for people with normal vision, it was 0.39–0.59.[5,10,16] In the study of Santo et al. and Hallemans et al., the stance phase in blind people was lower than in sighted people, while in Nakamura's study, this phase was higher.[5,10,16]

Three studies have examined the swing phase between eyes open in the control and experimental groups, which was significant only in the study of Santo et al.[16] Compared to the individuals with normal vision, the blind individuals showed a significant reduction in the swing phase.

Double support and single support

Double support is when both feet are in contact with the ground.[17] In the gait cycle, double support happens twice (at the beginning and end of the stance phase). In contrast, single support occurs when one foot is in contact with the ground.[18] The analysis of single gait parameters in four studies revealed that blind and low-vision people presented increased double-support duration compared to the control group.[5,6,15,16] Duration of single support was examined in two studies; however, only in Gazzellini et al.'s study, this relationship was significant. This parameter is prolonged in the congenital blind compared to controls.[6,15]

Discussion

By evaluating and summarizing the spatiotemporal gait measures like instrumented gait analysis techniques, this review provides some answers to the question: Which spatiotemporal gait parameters can differentiate between blind and sighted people?

Spatiotemporal gait parameters are associated with functional conditions, for example, fear and risk of falling, risk of cognitive decline, and monitoring disease progression or in assessing the efficiency of surgical or physical intervention so that they can provide useful information.[4,19] The STPs focused on in this study were walking speed, stride length, step length, stance and swing phase, step width, cadence, and double and single support.

The gait pattern of blind and low-vision people is characterized by a slower walking speed, shorter stride length, increased step width, decreased cadence, prolonged duration of double support, and reduced single support compared to nonvisually impaired people. Among the nine spatiotemporal gait parameters mentioned, a significant difference in these factors has been seen between sighted and visually impaired people in at least one and at most five studies.[5,6,10,11,15,16]

The parameter which was examined in all studies of this review was walking speed. Walking speed was significantly slower in five study participants when compared to sighted people. In Hallemans et al.'s study, no significant relationship was found in speed between blind and sighted people. Perhaps, the differences in the study protocol play a role in speed because participants were more familiar with the setup. There are several hypotheses about reducing walking speed in blind and visually impaired people.[11] According to Waters et al. and some of the studies reported in their work, average people choose to walk at a pace close to the optimum speed.[20] It has been reported that reduced walking speed is connected with slow decision-making, hearing problems, and visual impairments.[21] Observations have indicated that totally blind and visually impaired pedestrians walk more slowly when they are stressed, and it has been concluded that their walking speed can be a manifestation of their stress level.[22]

Several reports deal with the effects of walking speed on step width, cadence, stride length, stance, and swing durations, and on stance-phase knee flexion and peak joint forces.[23] It is believed that the reduction of step and consequent decrease of stride are related to the deficit of dynamic balance during gait, which has been described by Nakamura and Hallemans, mainly due to a backward inclination posture of the trunk.

Although there is a need for further investigations to clarify the generated hypotheses, researchers discuss that decreasing the length of step/stride implies a reduction in gait velocity of visually impaired individuals contrarily to individuals with normal vision.[16] Another hypothesis is that the reduction in stride and step length in visually impaired individuals may result from a protective mechanism that allows the individual to have additional time to process the external stimulus while maintaining adequate drop-off detection awareness over the pass of travel.[24]

Additional factors, such as age, leg length, gender, and body weight, effectively affect the human gait characteristic.[22,25] However, due to the limited number of participants in these studies, these factors have not been considered. The study conducted by Hallemans et al. revealed that aging positively impacts the motor performance of individuals who have normal visual abilities, suffer from an impairment, or are totally blind. However, the differences between groups were observed in the spatial parameters of gait and the timing of the different phases of the gait cycle. In particular, whole-blind individuals show adaptations in their gait patterns.[5]

The only study that has taken into consideration the time of vision loss is the one carried out by Nakamura. The results of his research showed that the longer the duration of vision loss in late-blind people is, the more their gait patterns approximate to congenitally blind people.[10] Research has indicated that providing visually impaired people with feedback or feedforward input can ameliorate their walking pace.[10]

Gait STPs that are used to predict the degree of disability have been associated with several adverse health outcomes, including the risk of falling, functional decline, and mortality in a wide range of populations.[4,26,27] Studies show that improving STPs can be considered a factor for increased balance, movement efficiency, and quality of life.[28,29] Therefore, by emphasizing these parameters in rehabilitation, it is possible to improve the walking of blind people.

It is suggested that some future studies be conducted on people with severe visual impairment. It is also recommended, besides spatiotemporal factors, to examine other aspects of kinetic gait parameters.

This literature review included the search of only three electronic databases (PubMed, Web of Science, and Scopus), which may be considered a limitation. In addition, only studies that employed three-dimensional gait analysis tools were included in this study.

Conclusion

The differences in gait kinematics are observed among normally sighted adults and those individuals with a visual impairment, which indicates that vision has an absolutely crucial role in controlling movement even if the surrounding environment is safe and even.

STPs, including walking velocity, cadence, and step/stride length, would appear to be the most relevant biomechanical parameters for people with visual impairment in gait analysis.

Conflicts of interest

There are no conflicts of interest.

Appendix 1: Search strategy

PubMed/MEDLINE syntax
1	gait[Title] OR “biped gait”[Title] OR “gait analysis”[Title] OR “gait training”[Title] OR “pattern walking”[Title] OR “walking pattern”[Title] OR “Walking Speed”[Title] OR “gait variability”[Title] OR spatiotemporal[Title] OR “step length”[Title] OR “stride length”[Title] OR “step width”[Title] OR “stride width”[Title] OR “step time”[Title] OR “stride time”[Title] OR “stance time”[Title] OR “swing time”[Title] OR “single support time”[Title] OR “double support time”[Title] OR “step to step”[Title] OR walk[Title] OR locomot[Title] OR ambulatory[Title] OR mobility[Title] OR Cadence)[Title]
2	Amaurosis Fugax”[Title] OR blind[Title] OR blinding[Title] OR blindness[Title] OR “visual disorder”[Title] OR “Vision Disorders”[Title] OR “Blind person”[Title] OR “blind people”[Title] OR “visual deprivation”[Title] OR “Visual impairment”[Title] OR “vision impairment”[Title] OR “vision impaired”[Title] OR “impaired vision”[Title] OR “sight impairment”[Title] OR “vision defect”[Title] OR “vision loss”[Title] OR “visual loss”[Title] OR “visual handicap”[Title] OR amaurosis[Title] OR “no light perception”[Title] OR “absence of vision”[Title] OR “congenital blindness”))[Title]
3	gait[Abstract] OR “biped gait”[Abstract] OR “gait analysis”[Abstract] OR “gait training”[Abstract] OR “pattern walking”[Abstract] OR “walking pattern”[Abstract] OR “Walking Speed”[Abstract] OR “gait variability”[Abstract] OR spatiotemporal[Abstract] OR “step length”[Abstract] OR “stride length”[Abstract] OR “step width”[Abstract] OR “stride width”[Abstract] OR “step time”[Abstract] OR “stride time”[Abstract] OR “stance time”[Abstract] OR “swing time”[Abstract] OR “single support time”[Abstract] OR “double support time”[Abstract] OR “step to step”[Abstract] OR walk[Abstract] OR locomot[Abstract] OR ambulatory[Abstract] OR mobility[Abstract] OR Cadence)[Abstract]
4	Amaurosis Fugax”[Abstract] OR blind[Abstract] OR blinding[Abstract] OR blindness[Abstract] OR “visual disorder”[Abstract] OR “Vision Disorders”[Abstract] OR “Blind person”[Abstract] OR “blind people”[Abstract] OR “visual deprivation”[Abstract] OR “Visual impairment”[Abstract] OR “vision impairment”[Abstract] OR “vision impaired”[Abstract] OR “impaired vision”[Abstract] OR “sight impairment”[Abstract] OR “vision defect”[Abstract] OR “vision loss”[Abstract] OR “visual loss”[Abstract] OR “visual handicap”[Abstract] OR amaurosis[Abstract] OR “no light perception”[Abstract] OR “absence of vision”[Abstract] OR “congenital blindness”))[Abstract]
5	1 AND 2
6	3 AND 4
7	1 AND 2 OR 3 AND 4
Scopus syntax
TITLE-ABS((gait OR “biped gait” OR “gait analysis” OR “gait training” OR “pattern walking” OR “walking pattern” OR “Walking Speed” OR “gait variability” OR spatiotemporal OR “step length” OR “stride length” OR “step width” OR “stride width” OR “step time” OR “stride time” OR “stance time” OR “swing time” OR “single support time” OR “double support time” OR “step to step” OR walk OR locomot OR ambulatory OR mobility OR Cadence) AND (“Amaurosis Fugax” OR blind OR blinding OR blindness OR “visual disorder” OR “Vision Disorders” OR “Blind person” OR “blind people” OR “visual deprivation” OR “Visual impairment” OR “vision impairment” OR “vision impaired” OR “impaired vision” OR “sight impairment” OR “vision defect” OR “vision loss” OR “visual loss” OR “visual handicap” OR amaurosis OR “no light perception” OR “absence of vision” OR “congenital blindness”))