Original articleCharacteristics of clinical measurements between biomechanical responders and non-responders to a shoe designed for knee osteoarthritis
Introduction
Knee osteoarthritis (OA) is the most prevalent disease amongst individuals aged 50 years and older in South Korea, affecting approximately 12.5% [1]. Clinical characteristics of knee OA are: pain, decreased range of motion, joint instability, muscle weakness, joint stiffness, and proprioceptive loss, all of which decrease quality of life [2].
The knee adduction moment (KAM) during walking in patients with degenerative knee OA has been discussed in previous studies [3], [4], [5], [6]. The KAM is primarily calculated by the ground reaction force and its lever arm. The KAM contributes to adduction of the knee and genu-varus deformities, which are significantly correlated with OA severity [7]. Therefore, reduction of the external KAM during walking is clinically important for treatment of OA. Biomechanical interventions such as: orthotic shoe inserts [8], knee braces [9], [10], and specialized footwear [11], [12], [13], [14] for knee OA aim to improve pain, decrease joint loading, and delay disease progression.
Over the past two decades, specialized footwear has been developed for the potential conservative management of knee OA [12]. Recently, Shakoor et al. reported that, following use of specialized mobility footwear, the Flex-OA shoe, the KAM was reduced by 18% compared to use of the participants’ own shoe [14]. Although the Flex-OA shoe had a significant effect on KAM, no study has explored whether this effect is universal or whether responder and non-responder groups may exhibit differences in clinical and biomechanical measurements. Therefore, the purpose of this study was to explore differences in KAM in a healthy population when wearing a standard shoe and the Flex-OA shoe, and to investigate the characteristics of individuals’ responses from biomechanical and clinical assessments.
Section snippets
Participants
This study recruited 32 healthy volunteers who consented to participate in the study and met the selection criteria. There were twenty-four males and eight females in the study population. Participants were given a detailed explanation of the study procedure and written informed consent was obtained. This study was conducted in accordance with the principles of the Declaration of Helsinki and was approved by the STEMH Ethics Committee of the University of Central Lancashire (STEMH 347).
Results
The mean of walking speed in both the Flex-OA shoe and the standardised shoe of all participants were 1.435 ± 0.126 m/s, and 1.433 ± 0.142 m/s, respectively and there was no significant difference in walking speed between shoe conditions (p = 0.811). Significant differences were observed in the KAMs between conditions and knee sides in various stance phases (Table 1). The first peak of the KAM during loading (0–25% of stance phase) showed that the Flex-OA shoe condition significantly decreased KAM for
Discussion
We observed that, in 32 subjects, 22 of 64 healthy knees, experienced negative or minimal effect on KAM during walking when wearing the Flex-OA shoe. Therefore, this study examined whether clinical and biomechanical measurements could distinguish between KAM response/non-response subgroups in healthy individuals.
The clinical and biomechanical measurements used in the study were directly related to the coronal and transverse planes, which are arguably the most important considerations for
Conflict of interest statement
We can confirm that there is no conflict of interests for any of the authors.
Acknowledgments
The shoes were supplied by DJO Global, Inc. The suppliers played no role in the design, execution, analysis and interpretation of the data or writing of this study. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
References (39)
- et al.
Gait characteristics of patients with knee osteoarthritis
J. Biomech.
(2001) - et al.
Increased knee joint loads during walking are present in subjects with knee osteoarthritis
Osteoarthr. Cartil.
(2002) - et al.
Effects of foot orthoses and valgus bracing on the knee adduction moment and medial joint load during gait
Clin. Biomech.
(2008) - et al.
The effect of valgus braces on medial compartment load of the knee joint—in vivo load measurements in three subjects
J. Biomech.
(2011) - et al.
Effect of footwear on the external knee adduction moment—a systematic review
Knee
(2012) - et al.
A six degrees-of-freedom marker set for gait analysis: repeatability and comparison with a modified Helen Hayes set
Gait Posture
(2009) - et al.
Predicting knee osteoarthritis risk in injured populations
Clin. Biomech.
(2017) - et al.
Ankle motion influences the external knee adduction moment and may predict who will respond to lateral wedge insoles? An ancillary analysis from the SILK trial
Osteoarthr. Cartil.
(2015) - et al.
Development and validation of a novel rating system for scoring standing foot posture: the foot posture index
Clin. Biomech.
(2006) - et al.
Symmetrical and asymmetrical hip rotation and its relationship to hip rotator muscle strength
Clin. Biomech.
(2010)
A comparison of the biomechanical effects of valgus knee braces and lateral wedged insoles in patients with knee osteoarthritis
Gait Posture
Hip rotation range of motion in people with and without low back pain who participate in rotation-related sports
Phys. Ther. Sport
Dynamic loading of the knee and hip joint and compensatory strategies in children and adolescents with varus malalignment
Gait Posture
The knee adduction moment during gait in subjects with knee osteoarthritis is more closely correlated with static alignment than radiographic disease severity, toe out angle and pain
J. Orthop. Res.
Normative values for the foot posture index between right and left foot: a descriptive study
Gait Posture
The influence of exercise on an unstable surface on the physical function and muscle strength of patients with osteoarthritis of the knee
J. Phys. Ther. Sci.
Quadriceps strength and osteoarthritis progression in malaligned and lax knees
Ann. Intern. Med.
Knee joint loading differs in individuals with mild compared with moderate medial knee osteoarthritis
Arthritis Rheum.
The relationship between the load on the knee joint during walking and the biomechanical characteristics of single-leg standing
J. Phys. Ther. Sci.
Cited by (10)
A novel anteroposterior axis of the tibia for total knee arthroplasty: An upright weight-bearing computed tomography analysis
2022, KneeCitation Excerpt :A recent systematic review highlighted the importance of evaluating knee adduction moment (KAM) in patients undergoing TKA [19] because KAM is closely associated with implant durability [20 21 22 23]. The first peak KAM is the most significant during the stance phase [24], and a reduction in peak KAM may reduce the overall mechanical stress applied to the medial compartment, reducing the risk of prosthetic loosening. The upright weight-bearing AP axis was positioned in about 7.4° of internal rotation relative to the traditional Akagi’s line, potentially because of the presence of screw-home movement [24].
Reliability and sensitivity of an instrument for measuring the midfoot passive mechanical properties
2020, Journal of BiomechanicsCitation Excerpt :Therefore, the Foot Torsimeter is a reliable instrument to measure the MFJC passive stiffness. Further studies are still necessary to verify the contribution of the MFJC stiffness to foot mechanics, as well as to investigate its role in identifying individuals that might be responsive to the use of corrective shoe insoles (Kim et al., 2018). In conclusion, based on our results, the following variables are recommended for consideration in future studies: MFJC resting angle, peak torques, and mean stiffnesses.
The effects of three quarter and full length foot orthoses on knee mechanics in healthy subjects and patellofemoral pain patients when walking and descending stairs
2018, Gait and PostureCitation Excerpt :Footwear type was standardised to training shoes, however participants wore their own shoes and variations in design could have influenced the findings. No consideration was given to individuals being biomechanical responders/non-responders to the foot orthoses within the different groups, this is an important consideration for future work and has been recently highlighted by Kim et al. [33]. This study identified potentially important differences in the knee mechanics between the PFP patients with a FPI >6 and the healthy group during walking and step descent.
Do different multi-segment foot models detect the same changes in kinematics when wearing foot orthoses?
2022, Journal of Foot and Ankle ResearchComparison of the effects of foot-toe orthoses on three-dimensional pelvic kinematics in individuals with hallux valgus during gait
2022, Prosthetics and Orthotics International