Ankle Eversion Research Articles

The effect of foot orthoses on gait biomechanics and pain among people with rheumatoid arthritis: A quasi-experimental study

BackgroundFoot pain is frequent among people with rheumatoid arthritis (RA). Foot orthoses (FO) are commonly prescribed with the intention to reduce pain symptoms and improve function. Research questionHow do a custom-made FO affect pain, gait biomechanics and daily activity among people with RA? MethodsTwenty-five participants with RA and foot pain completed this quasi-experimental study using a control insole for four weeks and then a custom-made FO in the following four weeks. The foot orthoses were customized by plantar foot shape targeting optimal restoration of normal arch height. A visual analog scale was used to monitor changes in ankle/foot, knee, hip joints, and global arthritis pain. In addition, the perceived pain area was measured using a body chart analysis. Kinematics and kinetics of the hip, knee and ankle joints during gait were analyzed using 3D-motion capture. Daily steps were measured with a wrist-based activity tracker for both the control insole and custom-made FO period, respectively. ResultsIn comparison to the control insole, the custom-made FO reduced ankle/foot pain intensity (p < 0.001) in addition to a reduction of the perceived pain areas in the feet (p < 0.001), legs (p = 0.012), as well as the arms and hands (p = 0.014). Ankle plantar flexion and eversion moments were also reduced (p < 0.001). No difference in daily steps was observed between the two periods (p = 0.657). SignificanceThis study has demonstrated an ankle/foot pain-relieving effect in conjunction with alterations of the ankle joint moments in people with RA using custom-made FO. The pain relief is plausibly attributed to alterations of the ankle joint moments when using the custom-made FO. However, future studies are needed to explore further into therapeutic implication of custom-made FO in pain management of people with RA.

The Immediate Carryover Effects of Peroneal Functional Electrical Stimulation Differ between People with and without Chronic Ankle Instability.

Chronic ankle instability (CAI) is a common condition that may develop after an ankle sprain. Compared with healthy individuals, those with CAI demonstrate excessive ankle inversion and increased peroneal electromyography (EMG) activity throughout the stance phase of gait, which may put them at greater risk for re-injury. Functional electrical stimulation (FES) of targeted muscles may provide benefits as a treatment modality to stimulate immediate adaptation of the neuromuscular system. The present study investigated the effect of a single, 10 min peroneal FES session on ankle kinematics and peroneal EMG activity in individuals with (n = 24) or without (n = 24) CAI. There were no significant differences in ankle kinematics between the groups before the intervention. However, after the intervention, healthy controls demonstrated significantly less ankle inversion between 0–9% (p = 0.009) and 82–87% (p = 0.011) of the stance phase. Furthermore, a significant within-group difference was observed only in the control group, demonstrating increased ankle eversion between 0–7% (p = 0.011) and 67–81% (p = 0.006) of the stance phase after the intervention. Peroneal EMG activity did not differ between groups or measurements. These findings, which demonstrate that peroneal FES can induce ankle kinematics adaptations during gait, can help to develop future interventions for people with CAI.

Lower impact forces but greater burden for the musculoskeletal system in running shoes with greater cushioning stiffness

ABSTRACT In a recent randomised trial investigating running shoe cushioning, injury risk was greater in recreational runners who trained in the shoe version with greater cushioning stiffness (Stiff) compared to those using the Soft version. However, vertical impact peak force (VIPF) was lower in the Stiff version. To investigate further the mechanisms involved in the protective effect of greater cushioning, the present study used an intra-subject design and analysed the differences in running kinematics and kinetics between the Stiff and Soft shoe versions on a subsample of 41 runners from the previous trial. Data were recorded in the two shoe conditions using an instrumented treadmill at 10 km.h−1. VIPF was confirmed to be lower in the Stiff version compared to the Soft version (1.39 ± 0.25 vs. 1.50 ± 0.25 BW, respectively; p = 0.009, d = 0.42), but not difference was observed in vertical loading rate (p = 0.255 and 0.897 for vertical average and instantaneous loading rate, respectively). Ankle eversion maximal velocity was not different (p = 0.099), but the Stiff version induced greater ankle negative work (−0.55 ± 0.09 vs. −0.52 ± 0.10 J.kg−1; p = 0.009, d = 0.32), maximal ankle negative power (−7.21 ± 1.90 vs. −6.96 ± 1.92 W.kg−1; p = 0.037, d = 0.13) and maximal hip extension moment (1.25 ± 0.32 vs.1.18 ± 0.30 N.m.kg−1; p = 0.009, d = 0.22). Our results suggest that the Stiff shoe version is related to increased mechanical burden for the musculoskeletal system, especially around the ankle joint. Trial registration: ClinicalTrials.gov identifier: NCT03115437.

Morphological and Functional Characteristics of the Peroneus Muscles in Patients with Lateral Ankle Sprain: An Ultrasound-Based Study.

Background and Objectives: The effectiveness of multiple ultrasound evaluations of the peroneus muscles morphology, including muscle cross-sectional area (CSA) and connective tissue, after lateral ankle sprain (LAS) is unknown. This study aimed to measure the peroneus muscles after LAS at three points, adding distal 75% to the conventional measurement points, in order to obtain a detailed understanding of the post-injury morphology and to propose a new evaluation index of the peroneus muscles for multiple LAS. Materials and Methods: Participants with and without LAS (LAS and control groups, 16 each) were recruited. The muscle cross-sectional area (CSA) and muscle echogenicity were measured using a B-mode ultrasound system at 25%, 50%, and 75% proximal to the line connecting the fibular head to the lateral malleolus. The ankle evertor strength was measured using a handheld dynamometer. Simultaneously, the peroneus longus (PL) and peroneus brevis (PB) muscle activities were measured using surface electromyography. Measurements for the LAS side, non-LAS side, and control leg were performed separately. Results: The CSA was significantly higher at 75% on the LAS side than on the non-LAS side and in the control leg. Muscle echogenicity of the LAS side at 75% was significantly lower than that of the non-LAS side and the control leg. Muscle activity of the PL was significantly lower and the PB was higher on the LAS side than on the non-LAS side and in the control leg. Conclusions: The PL was less active than the PB, while the PB was found to be overactive, suggesting that PB hypertrophy occurs due to an increase in the percentage of muscle fibers and a decrease in the connective tissue. Therefore, it is necessary to evaluate the condition of the PL and PB separately after LAS.

Tarsal Tunnel Syndrome Following Medializing Calcaneal Osteotomy

Category:HindfootIntroduction/Purpose:The tarsal tunnel syndrome is a compressive neuropathy that affects either the posterior tibial nerve, within the tarsal tunnel, or one of its terminal branches. It can be caused by extrinsic or intrinsic factors. Even though the tarsal tunnel syndrome has been reported as a complication of lateralizing calcaneal osteotomy, we have not identified in the literature reports of this syndrome associated to medializing calcaneal osteotomy. We report the case of a 60-year-old female who developed a tarsal tunnel syndrome, on the third postoperative week, following a medializing calcaneal osteotomy for flatfoot correction with stage IIB posterior tibial tendon dysfunction.Methods:We reviewed and obtained the information from the medical records of this patient: clinical examination, radiographs, computed tomography, magnetic resonance imaging, and outcome. Pain was assessed with visual analog scale (VAS).Results:The patient is a 60-year-old female with left stage II posterior tibial tendon dysfunction who failed to respond to conservative treatment. Medializing and lengthening (Evans) osteotomies of the calcaneus were performed, together with posterior tibial tendon repair and spring ligament reconstruction. In the postoperative, after a cast replacement into a more plantigrade position, the patient developed symptoms that suggested a compressive neuropathy of posterior tibial nerve within the tarsal tunnel associated to calcaneal medializing osteotomy. Initial conservative treatment failed and the posterior tibial nerve was explored under loupe magnification and the tarsal tunnel was released. Figure 1. An immediate improvement in pain was observed postoperatively and almost full recovery occurred within 6 months.Conclusion:In our case report, the tarsal tunnel syndrome was a consequence of the osteotomy fragment displacement that generated a reduction of the tarsal tunnel volume. It has been described that the tarsal tunnel syndrome symptoms become more evident with ankle dorsiflexion and eversion, in our patient this can be associated with the symptom exacerbation presented when the cast was placed into plantigrade position. We conclude that even though in the literature the tarsal tunnel syndrome has been mainly associated to lateralizing osteotomies, it is important to take this complication into account when performing a medializing osteotomy.

Association between Force Fluctuation During Isometric Ankle Eversion and Variability of Neural Drive in Peroneus Muscles

Association between Force Fluctuation During Isometric Ankle Eversion and Variability of Neural Drive in Peroneus Muscles

Ankle range of motion and dynamic balance in recreational Sepak Takraw players with and without ankle injury - a comparative study

Background and Study Aim. Sepak Takraw (ST) is considered Malaysia's national sport, and the nature of this sport requires players to be sufficiently acrobatic. Therefore, players were expected to jump and regain their balance, challenging their dynamic balance (DB). Nonetheless, range of motion (ROM) is closely related to balance. Hence, this study aimed to compare recreational ST players' ankle ROM and DB differences with and without ankle injuries.&#x0D; Material and Methods. The cross-sectional study in which 30 participants were assigned purposively according to players with an ankle injury (n=15) and without ankle injury (n=15) based on the position statement of the International Ankle Consortium (IAC). One time ankle Range of Motion and Dynamic balance was measured using a universal goniometer and Star Excursion Balance Test (SEBT), respectively, for both groups.&#x0D; Results. Independent T-test was performed to identify the significant differences (p&lt;0.05) of SEBT and ROM between the non-injured leg and injured leg within the injured group to the non-injured group. Ankle eversion and dorsiflexion between the injured and non-injured groups did not show any significant difference with p=0.35 &amp; p=0.53, respectively. As for SEBT, only posteromedial and medial of the injured leg did not show a significant difference p&gt;0.05. All other ankles ROM and the SEBT score demonstrated a statistically significant difference p&lt;0.05.&#x0D; Conclusions. ROM and DB training/rehabilitation should be incorporated to all the injured group ST sports players regardless of which leg is affected to optimize ankle function and the game performance.

Biomechanical Analysis of Running in Shoes with Different Heel-to-Toe Drops

The heel-to-toe drop of running shoes is a key parameter influencing lower extremity kinematics during running. Previous studies testing running shoes with lower or larger drops generally used minimalist or maximalist shoes, where the factors outside of the drop may lead to the observed changes in running biomechanics. Therefore, our aim was to compare the strike patterns, impact force, and lower extremity biomechanics when running in shoes that varied only in their drops. Eighteen habitual rearfoot strikers performed trials wearing running shoes with four drop conditions: 15 mm, 10 mm, 5 mm, and without a drop. Three-dimensional (3D) tracks of the reflective markers and impact force were synchronously collected using a video graphic acquisition system and two force plates. The biomechanical parameters were compared among the four drop conditions using one-way ANOVA of repeated measures. A greater foot inclination angle (p = 0.001, ηp2 = 0.36) at initial contact and a lower vertical loading rate (p = 0.002, ηp2 = 0.32) during the standing phase were found when running in shoes with large drops compared with running in shoes without a drop. Running in shoes with large drops, as opposed to without, significantly increased the peak knee extension moment (p = 0.002, ηp2 = 0.27), but decreased the peak ankle eversion moment (p = 0.001, ηp2 = 0.35). These findings suggest that the heel-to-toe drop of running shoes significantly influences the running pattern and the loading on lower extremity joints. Running shoes with large drops may be disadvantageous for runners with knee weakness and advantageous for runners with ankle weakness.

Effects of obesity and foot arch height on gait mechanics: A cross-sectional study.

Foot arch structure contributes to lower-limb joint mechanics and gait in adults with obesity. However, it is not well-known if excessive weight and arch height together affect gait mechanics compared to the effects of excessive weight and arch height alone. The purpose of this study was to determine the influences of arch height and obesity on gait mechanics in adults. In this study, 1) dynamic plantar pressure, 2) spatiotemporal gait parameters, 3) foot progression angle, and 4) ankle and knee joint angles and moments were collected in adults with normal weight with normal arch heights (n = 11), normal weight with lower arch heights (n = 10), obesity with normal arch heights (n = 8), and obesity with lower arch heights (n = 18) as they walked at their preferred speed and at a pedestrian standard walking speed, 1.25 m/s. Digital foot pressure data were used to compute a measure of arch height, the Chippaux-Smirak Index (CSI). Our results revealed that BMI and arch height were each associated with particular measures of ankle and knee joint mechanics during walking in healthy young adults: (i) a higher BMI with greater peak internal ankle plantar-flexion moment and (ii) a lower arch height with greater peak internal ankle eversion and abduction moments and peak internal knee abduction moment (i.e., external knee adduction moment). Our results have implications for understanding the role of arch height in reducing musculoskeletal injury risks, improving gait, and increasing physical activity for people living with obesity.

Does ankle inversion or eversion ROM correlate with maximal power output in collegiate women soccer players?

Background: Soccer requires participants to use speed, change of direction, which requires lower limb power production in order to perform at an optimal level. Soccer dribbling and passing creates extreme ankle inversion and eversion which is an important role towards improving soccer performance. The aim of this study was to determine if there is a relationship between ankle inversion or eversion ROM with dominant and non-dominant foot with maximal power production.

How Many Trials are Needed to Assess Ankle Joint Proprioception in Children with Chronic Ankle Instability?

The assessment of ankle joint repositioning is commonly used to detect joint impairment in people with chronic ankle instability (CAI). To decrease measurement fluctuation errors, it has been suggested that an average of 10 measurements be utilized. However, learning and tiredness difficulties, particularly in children, might make this difficult. Therefore, this study aimed to compare the repeatability of 3 and 10 measures of ankle joint repositioning using an isokinetic dynamometer (Biodex) in children with CAI. Ten children with CAI with an average age of 11.21 years were recruited in the study. The ankle inversion and eversion angles for 3 and 10 trials using active and passive reproduction protocols were recorded using Biodex Multi-Joint System 4TM. The error of reproduction angle was presented by the mean, correlation, and percentage changes for both active and passive reposition angles. The means of the error for ankle joint reproduction angles revealed no significant differences between 3 and 10 trials for both active and passive protocols (p &gt; 0.05). The ICC(3,1) revealed high correlations between 3 and 10 trials of assessments (ICC(3,1) = 0.82 - 0.91). The percentage changes of means and standard deviations showed learning effect of ankle joint proprioception measurement after the 4th and the 5th trials for inversion and eversion, respectively. Therefore, to prevent learning and fatigue effects, a 3-trial protocol would be more appropriate than a 10-trial protocol. However, a 4-trial protocol and a 5-trial protocol were suggested for inversion and eversion, respectively. The suggested protocols are recommended to use for further reliability studies of the ankle joint proprioception in children with CAI. HIGHLIGHTS Ankle joint reproduction assessments using active and passive protocols are needed to identify the impairment of joint position sense in children with chronic ankle instability To prevent fatigue effect, 3 trials are sufficient for testing of ankle joint position sense in children with chronic ankle instability In research setting, a 4-trial protocol for ankle joint inversion and a 5-trial protocol for ankle joint eversion are more appropriate than a 10-trial protocol

Effects of nail softness and stiffness with distance running shoes on ground reaction forces and vertical loading rates in male elite long-distance runners with pronated feet

BackgroundTo improve propulsion during running, athletes often wear spike shoes designed for training and/or competition. Running with spike shoes may cause pain and/or injuries. To address this problem, a modified spike shoe was tested. This study aimed to evaluate the effects of running with dual-versus single-stiffness spike running shoes on running mechanics in long-distance runners with pronated feet.MethodsSixteen male elite (national competitive level) runners (5000 or 10,000 m) aged 28.2 ± 2.5 years with pronated feet volunteered to participate in this study. To be included, participants had to have achieved personal best race times over 5- and/or 10-km races under 17 or 34 min during official running competitions. All participants were heel strikers and had a history of 11.2 ± 4.2 years of training. For the assessment of running kinetics, a force plate was imbedded into a walkway. Running kinematics were recorded using a Vicon-motion-capture system. Nike Zoom Rival shoes (Nike, Nike Zoom Rival, USA) were selected and adapted according to spike softness and stiffness. Participants ran at a constant speed of ~4.0 m/s across the walkway with both shoe conditions in randomized order. Six trials were recorded per condition. The main outcomes included peak ground reaction forces and their time-to-peak, average and instantaneous vertical loading rates, free moments, and peak ankle eversion angles.ResultsPaired t-tests revealed significantly lower lateral (p = 0.021, d = 0.95) and vertical (p = 0.010, d = 1.40) forces at heel contact during running with dual-stiffness spike shoes. Running with dual-stiffness spike shoes resulted in a significantly longer time-to-peak vertical (p = 0.004, d = 1.40) force at heel contact. The analysis revealed significantly lower average (p = 0.005, d = 0.46) and instantaneous (p = 0.021, d = 0.49) loading rates and peak negative free moment amplitudes (p = 0.016, d = 0.81) when running with dual-stiffness spike shoes. Finally, significantly lower peak ankle eversion angles were observed with dual-stiffness spike shoes (p < 0.001, d = 1.29).ConclusionsRunning in dual- compared with single-stiffness spike distance running shoes resulted in lower loading rates, free moment amplitudes, and peak ankle eversion angles of long-distance runners with pronated feet.

Is there a dose-response of medial wedge insoles on lower limb biomechanics in people with pronated feet during walking and running?

Although the effects of medial wedge insoles on lower limb biomechanics have been investigated, information about the effects of different magnitudes of medial posting is still lacking. What are the dose-response effects of medial wedge insoles with postings varying between 0 °, 3 °, 6 °, and 9 ° of inclination on the lower limb biomechanics during walking and running in individuals with pronated feet? Sixteen participants with an FPI ≥ 6 were recruited. Four arch-supported insole conditions with varying degrees of medial heel wedge were tested (0°, 3°, 6°, and 9°). A 3D motion analysis system with force plates was used to obtain the kinetics and kinematics of walking and running at self-selected speeds. To compare the ankle, knee, and hip angles and moments among conditions, a time series analysis was performed using Statistical Parametric Mapping (SPM). A reduction in ankle eversion angle was observed during walking for all insoles. For running, the 6° and 9° insoles decreased the ankle eversion angle during early stance and increased this angle during the propulsive phase. A decrease in ankle eversion moment was observed in walking and running for 6° and 9° insoles. An increase in knee adduction moment occurred in walking and running for all insoles. For hip, the 6° and 9° insoles showed, during walking, a decrease in hip adduction angle and an increase in hip adduction and external rotation moments. For most variables, statistical differences were found for a greater period across the stance phase as the medial wedge increased, except for ankle eversion moment and hip external rotation moment during walking. The biomechanical effects over the time series for many of the parameters increased with the addition of insole inclination, showing a dose-response effect of medial wedge insoles on the lower limb biomechanics during walking and running in adults with excessive foot pronation.

Three-dimensional joint kinematic and two-dimensional quality of movement comparison between lateral and forward step-downs

ObjectivesWhile lateral and forward step-down tasks are commonly used, they may have different kinematic and performance demands that could influence clinical assessment and rehabilitation. Therefore, the purpose of this study was to compare 3D lower extremity kinematics and 2D quality of movement between the tasks. DesignCross-sectional comparative study. SettingResearch laboratory. ParticipantsThirty healthy adults (18 females, age = 23.2 ± 1.4 years, BMI = 23.9 ± 2.2 kg/m2). Main outcome measuresParticipants underwent 3D and 2D motion analysis. 3D variables were peak hip, knee, and ankle angles. Dichotomous clinical criteria were used for 2D assessment. An alpha level of 0.05 was used for statistical analyses. ResultsIn the sagittal plane, the forward step-down averaged 7° more knee flexion (p < 0.001, d = 2.30) and 4° more ankle dorsiflexion (p < 0.001, d = 1.72), but 2° less hip flexion (p = 0.001, d = 0.64). In the frontal plane, forward step-downs averaged 1° more hip adduction (p = 0.006, d = 0.54) and 1° more ankle eversion (p < 0.001, d = 1.04). The forward step-down elicited 2D movement faults more often (p = 0.003). ConclusionsThe increased knee flexion and ankle dorsiflexion demands of the forward step-down were accompanied by increases in frontal plane aberrations. The forward step-down may be more challenging for individuals with reduced tolerance to loaded knee flexion and/or limited ankle mobility.

The immediate effects of foot orthosis geometry on lower limb muscle activity and foot biomechanics

Foot orthoses (FOs) are used to treat clinical conditions by altering the external forces applied to the foot and thereafter the forces of muscles and tendons. However, whether specific geometric design features of FOs affect muscle activation is unknown. The aim of this study was to investigate if medial heel wedging and increased medial arch height have different effects on the electromyography (EMG) amplitude of tibialis posterior, other muscles of the lower limb and the kinematics and kinetics at the rearfoot and ankle. Healthy participants (n = 19) walked in standardised shoes with i) a flat inlay; ii) a standard shape FOs, iii) standard FOs adjusted to incorporate a 6 mm increase in arch height, iv) and standard FOs adjusted to incorporate an 8° medial heel wedging and v) both the 6 mm increase in arch height and 8° increase in medial wedging. EMG was recorded from medial gastrocnemius, peroneus longus, tibialis anterior and in-dwelling tibialis posterior muscles. Motion and ground reaction force data were collected concurrently. Tibialis posterior EMG amplitude reduced in early stance with all FOs (ηp2 = 0.23–1.16). Tibialis posterior EMG amplitude and external ankle eversion moment significantly reduced with FOs incorporating medial wedging. The concurrent reduction in external eversion moment and peak TP EMG amplitude in early stance with medial heel wedging demonstrates the potential for this specific FOs geometric feature to alter TP activation. Medial wedged FOs could facilitate tendon healing in tibialis posterior tendon dysfunction by reducing force going through the TP muscle tendon unit.

Six-Week Remodeled Bike Pedal Training Improves Dynamic Control of Lateral Shuffling in Athletes With Functional Ankle Instability.

Remodeled bicycle pedal training with multidirectional challenges through muscle strengthening and neuromuscular facilitation may increase dynamic postural control and performance during lateral shuffling for athletes with functional ankle instability (FAI). The 6-week remodeled bicycle pedal training is effective on the ankle joint control and muscle activation, and especially that of the ankle evertor muscle co-contraction to improve dynamic postural control during lateral shuffling for athletes with FAI. Laboratory randomized controlled trial. Level 2. Fourteen healthy athletes (healthy group) and 26 athletes with FAI aged 18 to 30 years were included in the study. The athletes with FAI were randomly assigned to either the training group (FAI-T group) or the nontraining group (FAI-NT group). The athletes in the FAI-T group underwent 6 weeks of remodeled bicycle pedal training, whereas those in the FAI-NT group did not undergo any intervention. Muscle co-contraction index and muscle activation in the initial contact (IC) and propulsion phases, and ankle joint angle in the IC and propulsion phases were measured during lateral shuffling before and after 6 weeks of training. After remodeled bicycle pedal training, the FAI-T group demonstrated greater muscle activation in the hamstring (P = 0.01), greater muscle coactivation of the tibialis anterior (TA) and the peroneus longus (P = 0.01), and greater ankle eversion angle in the IC phase. Significantly greater muscle activation of the TA (P = 0.01), greater coactivation of quadriceps and hamstring (P = 0.03), and a smaller ankle inversion angle (P = 0.04) in the propulsion phase were observed in the FAI-T group after training compared with those in the FAI-NT group. Remodeled bicycle pedal training facilitates the TA and peroneus longus activation and the coactivation of the quadriceps and hamstring muscles during lateral shuffling and resulted in enhanced ankle and knee joint stability. In addition, a better ankle movement strategy during a dynamic task can be achieved via a 6-week remodeled pedal training program. This remodeled bicycle pedal training can be effective for rehabilitating athletes with FAI to recover lateral dynamic movement capability.

Gait assist brace with double carbon fiber reinforced plastic spring blades to allow ankle joint movement and change in walking direction

Unpowered braces and exoskeletons, which are often made of carbon fiber reinforced plastic (CFRP), can assist lower limb movements and can be worn permanently. Furthermore, braces to be worn at all times must not hinder the change of direction, as this movement is nearly as essential as straight gait in daily life. Ankle joint movements, especially inversion and eversion, play a key role in changing the direction during walking. However, in the case of conventional short leg braces, the range of motion is limited because the single wide CFRP blade placed at the back of the leg cannot deform elastically. In this study, a gait assist system with two CFRP blades on the lateral and medial sides of the leg was developed. The system could effectively assist the gait and did not inhibit the change in the direction.

A shoe-insole to improve ankle joint mechanics for injury prevention among older adults

Technologies to assist senior individuals with active walking are important. This experiment aimed to investigate whether a customised insole geometry would reduce the risk of falls and locomotive injuries. The tested insole incorporated a built-in inclination to assist ankle dorsiflexion (2.2°) and eversion (4.5°). Twenty-six older adults and 30 younger counterparts undertook gait assessment with and without the experimental insole while 3 D motion capture and force plates recorded gait. The insole increased swing foot-ground clearance, with.43 cm for the older adults' dominant foot. The insole also prevented excessive lateral centre of pressure movement. The main insole effects on foot contact mechanics were (i) prolonged time to foot-flat (.015 s) and (ii) improved energy efficiency (2%). Reduced knee adduction moment (>15%) was observed in the older group. Shoe insoles to provide dorsiflexion and eversion support may have the potential to reduce the risk of falls and locomotion-related injuries for older adults. Practitioner Summary: Using 3 D gait assessment techniques this research investigated shoe-insoles incorporating ankle dorsiflexion and eversion support features. It was shown that falls risk and locomotive injuries could be reduced by the application of orthotics to support ankle dorsiflexion and eversion. Shoe-orthotics may provide practical low-cost solutions to correcting gait impairments. Abbreviations: MFC: minimum foot clearance; CoP: centre of pressure; OA: osteoarthritis; GRF: ground reaction forces; IREDS: infra-red light emitting diodes; PE: potential energy; KE: kinetic energy; IQR: interquartile range; ANOVA: analysis of variance

Real-time conversion of inertial measurement unit data to ankle joint angles using deep neural networks

Joint angle quantification from inertial measurement units (IMUs) is commonly performed using kinematic modelling, which depends on anatomical sensor placement and/or functional joint calibration; however, accurate three-dimensional joint motion measurement remains challenging to achieve. The aims of this study were firstly to employ deep neural networks to convert IMU data to ankle joint angles that are indistinguishable from those derived from motion capture-based inverse kinematics (IK) - the reference standard; and secondly, to validate the robustness of this approach across contrasting walking speeds in healthy individuals. Kinematics data were simultaneously calculated using IMUs and IK from 9 subjects during walking on a treadmill at 0.5 m/s, 1.0 m/s and 1.5 m/s. A generative adversarial network was trained using gait data at two of the walking speeds to predict ankle kinematics from IMU data alone for the third walking speed. There were significant differences between IK and IMU joint angle predictions for ankle eversion and internal rotation during walking at 0.5 m/s and 1.0 m/s (p < 0.001); however, no significant differences in joint angles were observed between the generative adversarial network prediction and IK at any speed or plane of joint motion (p < 0.05). The RMS difference in ankle joint kinematics between the generative adversarial network and IK for walking at 1.0 m/s was 3.8°, 2.1° and 3.5° for dorsiflexion, inversion and axial rotation, respectively. The modeling approach presented for real-time IMU to ankle joint angle conversion, which can be readily expanded to other joints, may provide enhanced IMU capability in applications such as telemedicine, remote monitoring and rehabilitation.

Inter- and Intra-Rater Reliability of Handheld Dynamometry for Lower Extremity Strength Testing in Pre-Professional Dancers.

Handheld dynamometry (HHD) using external fixation has demonstrated high inter- and intra-rater reliability. Handheld dynamometry offers an objective way to quantify strength; however, setting up external stabilization devices for HHD can be time consuming. This study examined the reliability of HHD for lower extremity strength in dancers using body weight stabilization. Twenty-six pre-professional dancers (age: 20.64 ± 2.21 years) were recruited and assessed by three testers: an experienced physical therapist (ePT), a novice physical therapist (nPT), and a student physical therapist (SPT). To avoid testing fatigue, dancers were divided into two testing groups and were evaluated on separate weekends. Testers used HHD to test isometric force production of six muscle groups in the first cohort and seven dif- ferent muscle groups in the second cohort. Testing positions were standardized and utilized a "make" test protocol. Intra- class correlation coefficients (ICC), 95% confidence interval, and standard error of measurement were calculated for each position. Inter-rater reliability was > 0.75 for all ICC measures except knee extension and ankle eversion. Intra-rater reliability was > 0.75 for all ICC measures except the ePT (tester A) day 2 for hip extension, internal rotation seated, knee extension, and ankle dorsiflexion; nPT (tester B) day 1 knee flexion; and SPT (tester C) for day 1 knee extension and ankle eversion and days 1 and 2 for ankle dorsiflexion and inversion. It is concluded that HHD can reliably measure force production of hip, knee, and ankle muscle groups without use of external fixation devices.