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This study was conducted to determine running kinematics while using compression socks (CS) and smooth socks (SS) among 16 recreational runners. They were required to complete a maximal treadmill test with two different running sock conditions (smooth and compression). All kinematic parameters (ground contact time, heel strike, stride length and swing time) were reported in an average of the four stages of Bruce protocol. Results showed more significant correlations (p

Background and objective: Tightness of the gastroc–soleus muscle complex is one of the limiting factors of the ankle joint’s range of motion (ROM) during daily activities. The aim of this study was to investigate the effectiveness of functional and extra-functional stretching of the gastrocnemius–soleus complex on knee joint loading in athletes with limited ankle dorsiflexion. Material and methods: In this cross-sectional study, 30 male athletes with gastrocnemius–soleus shortness were recruited and randomly divided into three equal-size groups of functional stretching, extra-functional stretching, and a control group. The extra-functional stretching group performed stretching exercises three times per day for eight weeks. The functional stretching group was instructed to change their gait pattern via increased heel strike during daily activities. Results: None of the stretching programs reduced the knee flexion angle in heel contact (p > 0.05). The knee flexion angle was significantly increased in the stance phase in the functional group (p ≤ 0.05). Walking speed was increased significantly in the extra-functional group (p ≤ 0.05). The knee adductor moment and external rotation moment decreased significantly in the functional group (p ≤ 0.05). Conclusion: An eight-week functional stretching program in this study led to a reduction of knee loading in the frontal and horizontal planes in comparison to the extra-functional stretching group, demonstrating the effectiveness of functional stretching in improving knee joint biomechanics during walking.

To determine if anterior cruciate ligament (ACL) reconstruction (ACLR) with lateral extraarticular tenodesis (LET) is beneficial for restoring knee kinematics with concomitant meniscal pathology causing rotatory knee instability. Twenty patients with an ACL tear were randomized to either isolated ACLR or ACLR with LET. Patients were divided into four groups based on the surgery performed and the presence of meniscal tear (MT): ACLR without MT, ACLR with MT, ACLR with LET without MT, and ACLR with LET with MT. Kinematic data normalized to the contralateral, healthy knee were collected using dynamic biplanar radiography superimposed with high-resolution computed tomography scans of patients’ knees during downhill running. Anterior tibial translation (ATT) and tibial rotation (TR) as well as patient-reported outcome measures (PROMs) were analyzed at 6- and 12-months postoperatively. At 6 months, ACLR with LET resulted in significantly decreased ATT at heel strike compared to ACLR (ACLR without MT: 0.3 ± 0.8 mm and ACLR with MT: 1.4 ± 3.1 mm vs. ACLR with LET without MT: − 2.5 ± 3.4 mm and ACLR with LET with MT: − 1.5 ± 1.2 mm ATT, p = 0.02). At 6 months, at toe off ACLR with LET better restored ATT to that of the contralateral, healthy knee in patients with meniscal pathology, while in patients without meniscal pathology, ACLR with LET resulted in significantly decreased ATT (1.0 ± 2.6 mm ATT vs. − 2.6 ± 1.7 mm ATT, p = 0.04). There were no significant differences in kinematics or PROMs between groups at 12 months. For combined ACL and meniscus injury, ACLR with LET restores native knee kinematics at toe off but excessively decreases ATT at heel strike in the early post-operative period (6 months) without altering knee kinematics in the long term. Future large-scale clinical studies are needed to better understand the function of LET and ultimately improve patient outcomes. III.

Background Women are twice as likely as men to develop knee osteoarthritis (OA), and with it experience greater losses of physical function and disability. A change in the mechanical environment of the joint is a key initiating factor for knee OA. Differences in morphology, joint injury risk, and hormonal shifts in mid-life are often considered factors which increase OA risk for women. Pregnancy, a time of significant hormonal, morphological, and biomechanical change, has received comparably less attention. If morphological and biomechanical changes persist postpartum, this could increase OA risk for parous (childbearing) women. Research question Are lower limb gait mechanics different between healthy nulliparous (non-childbearing) and parous (childbearing) women? Methods Twenty-eight self-reported not pregnant female participants (14 parous, 14 nulliparous) were recruited for the study. Nulliparous participants had never given birth to a child. Parous participants had given birth to at least one full-term infant (37–42 weeks) without complications between one to five years before data collection. Motion capture of participants’ preferred, fast, and set (1.4 m/s) walking speeds was conducted. Repeated measures ANOVA were performed to test for significant group differences in joint kinematics and kinetics. Results There was a significant main effect of group indicating a larger knee flexion angle at toe off (p = 0.0002), smaller knee extension moment at heel strike (p = 0.0006), smaller first peak knee flexion moment (p = 0.040), and smaller peak hip adduction moment for the parous group compared to the nulliparous group (p = 0.003). Static Q-angle did not differ between groups. Significance Alteration in mechanics from the habitual loading pattern are thought to increase risk of OA. Smaller knee moments in post-partum women could alter the mechanical stimulus to cartilage, and should be investigated in conjunction with cartilage health measures to determine the link with OA initiation.

Tripping is accompanied by reduced minimum toe clearance (mTC) during the swing phase of gait. The risk of fall due to tripping among transfemoral amputees is nearly 67% which is greater than the transtibial amputees. Therefore, intervention to improve mTC can potentially enhance the quality of life among transfemoral amputees. In this paper, we first develop a real-time visual feedback system with center of pressure (CoP) information. Next, we recruited six non-disabled and three transfemoral amputees to investigate the effect on mTC while participants were trained to shift the CoP anteriorly/posteriorly during heel strike. Finally, to assess the lasting effect of training on mTC, retention trials were conducted without feedback. During feedback, posterior shift in the CoP improved the mTC significantly from 4.68 ± 0.40 cm to 6.12 ± 0.68 cm (p 0.05) from feedback condition in amputee, suggesting a positive effect of feedback training. The foot-to-ground angle (FGA) at mTC increased significantly (p < 0.025) during posterior shift feedback in non-disabled suggests active ankle dorsiflexion in increasing mTC. However, in amputees, FGA at mTC did not differ significantly during both anterior and posterior CoP shift feedback. The present findings suggest CoP feedback as a potential strategy during gait rehabilitation of transfemoral amputees.

This paper proposes a gait detection model that can recognize important gait events in real time. Human gaits are periodic, with each gait cycle containing the important gait events of mid-swing, heel-strike (HS), and toe-off. The correct identification of different gait patterns caused by stroke or progressive neurodegenerative Parkinson’s disease could ensure that the patients receive appropriate treatment and rehabilitation strategies. However, online detection of gait events can be challenging because each person has their own walking patterns and speeds. This paper applies recurrent neural networks (RNNs) to develop a model that can instantly detect important gait events in any subject. We collected clinical gait data and used them to develop an RNN model for real-time detection of HS. The model correctly recognized HS events with an average success rate of 98.84% and an average delay of 0.024 s in the laboratory environment. We then applied the model to three different groups of subjects: healthy elderly subjects, stroke patients, and patients with Parkinson’s disease. The developed RNN model also correctly recognized HS events in all three groups with an average accuracy of more than 99.65%, even though the subjects had very different walking patterns. In the future, the developed gait detection model can be integrated with real-time rehabilitation systems to provide patients with repetitive guidance using clinician-determined cures for enhanced clinical gait training.

Older adults with hyperkyphosis might have a high risk of falls since their whole body center of mass may shift to the boundary of the base of support. Body composition changes, such as low bone mineral content (BMC), decreased muscle mass, high body mass index (BMI), and increased fat mass are common in older adults with hyperkyphosis. This study aimed to investigate the relationship between body composition and balance performance using a biomechanical analysis in older adults with hyperkyphosis. Thirty older adults with hyperkyphosis were recruited. BMC, muscle mass, BMI, and fat mass were measured for body composition. Balance performances were determined with walking, quiet standing, and forward reach. Gait speed, step length, center of mass–center of pressure inclination angle of heel strike (Inc-HS) and toe off (Inc-TO) during walking, center of mass–center of pressure inclination angle during quiet standing (Inc-QS), and reaching distance were calculated. BMC had a moderately positive correlation with gait speed (r = 0.48, p

This paper presents a low-cost wireless gait event detection system that incorporates infra-red range sensors mounted laterally at a specific anatomical location on the shoe. This system uses foot clearance information to extract heel strike (HS) and toe-off (TO) events. A subject-specific algorithm based on signature curve matching was developed to estimate the HS and TO in six able-bodied subjects and three transfemoral amputees. The data were acquired in a real-life environment while the subject walked on level ground and ramp terrains, including the transitions. The HS and TO in the level ground were detected with an accuracy of 22.87± 9.93 ms and 10.42± 6.70 ms, respectively, in able-bodied participants. The accuracy of 37.91± 12.36 ms and 20.41± 11.23 ms in HS and TO, respectively, was observed in amputees during level ground walking. Further, within the ramp terrain, the HS and TO were detected with an accuracy of 23.33± 11.20 ms and 13.36± 9.5 ms respectively in able-bodied subjects and 40.35± 12.64 ms and 47.51± 19.23 ms in amputees. This method reports comparable accuracy, with minimal standard deviation, to other existing methods based on accelerometer, gyroscope, electromyography, and force myography. This system is robust, easy to operate, and avoids direct contact with the body. The developed system offers a movable sensor platform in two degrees of freedom that facilitates the adaptability of the proposed system for different heel height and shoe sizes.

Foot prosthetics is one of the needs of the disabled feet as a tool for activities. The ankle prosthetic model is proposed as an alternative prosthetic model that is affordable to people with disabilities. The model is designed and analyzed to be able to withstand the average weight of a human being in the heel strike, midstance, and toe-off position and has a safe safety factor value. The research method used is the model design and model analysis consisting of preprocessing, solution, and post-processing. The analysis results showed that the greatest deformation occurred in the toe-off position of 1.52 mm when given a load of 500 N and 0.036 mm when given a moment of 5000 Nmm. The greatest strain energy was located in the forefoot area at a toe-off position of 0.6 mJ. Maximum stress also occurred at the toe-off position of 5.71 MPa. With a safety factor of 4.7, this model is categorized as safe because the stress that occurs is still below the yield strength limit of the ABS material.

This paper concerns the issue of the dynamic impact of people running on footbridges with particular with attention to various footstrike patterns occurring during the running (i.e. heel strike pattern and forefoot strike pattern). The results of a series of laboratory tests of vertical ground reaction force (VGRF) measurements generated by running people are presented along with the characteristics of the VGRF curves. Based on the results of the tests, a new proposal for a dynamic load model generated by people classified as heel strike runners has been developed, and corrections of the input parameters of two load models proposed by other authors have been performed. Moreover, the VGRF modelling technique using the Gaussian functions is presented along with a set of equations describing the variability of the Gaussian function parameters as a function of the frequency of running. The presented methods of the VGRF modelling allow increasing the accuracy of determining the VGRF values and, consequently, increasing the accuracy of dynamic analyses of footbridges subjected to dynamic loads generated by people running.