Maximum Dorsiflexion Research Articles

Biomechanical Changes to the Hindfoot After Zadek Osteotomy.

Insertional Achilles tendinopathy (IAT) is a common source of heel pain in active adults and athletes. The Zadek osteotomy (ZO) is a calcaneal dorsal closing wedge osteotomy that has demonstrated clinical success as a treatment for IAT, purported to favorably improve tendon mechanics, decrease impingement, and decrease pressure within the retrocalcaneal bursa. The present study aims to evaluate the biomechanical effects of ZO on Achilles strain, position of the Haglund prominence relative to the Achilles insertion, and retrocalcaneal pressure. The ZO was performed on 10 fresh-frozen foot and ankle mid tibia-fibula cadaveric specimens. An osteotomy was performed using a 1-cm dorsal closing wedge procedure secured with a 7.0 mm cannulated screw. Point pressure sensor catheters and differential variable reluctance transducers were used to measure the retrocalcaneal pressure and Achilles strain, respectively, pre- and postosteotomy. Paired t-tests were utilized to detect statistical differences (P < .05). After the ZO, the Haglund prominence was translated 9.9 mm anteriorly with respect to the insertion of the Achilles (P < .05) and the Achilles tendon insertion was translated 3.4 mm proximally (P < .05). The ratio of calcaneal length to greater tuberosity length, the X/Y ratio, increased from 2.56 to 3.52 with the osteotomy (P < .05). At maximum dorsiflexion, retrocalcaneal pressure decreased from 117 to 66 mm Hg (44%, P = .018). The Achilles strain changed from 0.00362 to 0.00436 in the anterior fibers (P = .484) and changed from 0.00467 to 0.00283 in the posterior fibers (P = .088). Biomechanical testing in a cadaveric model demonstrates that the ZO decreased retrocalcaneal pressure, shifted the Achilles tendon insertion proximally, increased the X/Y ratio of the calcaneus, and did not significantly change the strain of the Achilles tendon. Despite the clinical success demonstrated in recent literature, there are no biomechanical studies describing the effect of the ZO on the biomechanics of the hindfoot, and the mechanism of symptom relief of the ZO for IAT is not well understood. The present study measures two potential ZO effects relative to Haglund prominence by measuring retrocalcaneal pressure and displacement of the Achilles tendon with respect to the Haglund prominence, and measures one ZO effect relative to calcification of the tendon by measuring the Achilles tendon strain.

Randomized controlled trial on ankle biomechanics in the treatment of functional ankle instability with joint mobilization

Functional ankle instability (FAI) patients often experience restricted ankle dorsiflexion, increased inversion angle, and elevated ground reaction forces during walking, all related to altered kinematics of the talocrural and subtalar joints. This study aimed to investigate the potential positive impact of joint mobilization on FAI patients from a biomechanical perspective. The experimental group (EG, n = 17; Age: 20.06 ± 1.34 years; Height: 1.74 ± 0.07 m; Weight: 69.79 ± 11.20 kg; BMI:22.88 ± 2.63 kg/m2; CAIT:15.59 ± 2.58; M/F: 15/2) received joint mobilization + routine rehabilitation training, while the control group (CG, n = 16; Age: 20.50 ± 0.73 years; Height: 1.73 ± 0.09 m; Weight: 64.59 ± 7.21 kg; BMI: 21.65 ± 2.47 kg/m2; CAIT: 16.75 ± 2.21; M/F: 14/2) only received regular rehabilitation training. Biomechanical tests were performed in both groups after the 4-week intervention. The spatial parameters during walking (including step length, stride length, step width, step time, cadence, step speed, support time, and swing time), ankle flexion and dorsiflexion angle, inversion, and eversion angles, internal and external rotation angles, ankle torque, as well as the vertical ground reaction force were measured before and after the intervention. The results of the two-way ANOVA showed that the main effect of time was significant for step length (P < 0.001), stride length (P = 0.008), step speed (P < 0.001), the sagittal plane angle at touchdown (P < 0.001), maximum dorsiflexion angle (P = 0.005), sagittal plane toe off-ground angle (P < 0.001), peak flexion-dorsiflexion torque (P = 0.033), the first peak vGRF (P = 0.013), and second peak vGRF (P = 0.011). The main effect of Time * Group was significant for step speed (P = 0.044). The EG demonstrated significant improvements in step speed (P = 0.047), maximum dorsiflexion angle (P = 0.047), and the first peak vGRF (P = 0.028) compared to the CG. This study reveals that joint mobilization intervention enhances gait spatiotemporal parameters, kinematics, and kinetics, particularly in step speed, maximum dorsiflexion angle, and the first vGRF peak for the EG compared to the CG. Therefore, the rehabilitation strategy for patients with functional ankle instability should appropriately increase the use of joint movement to promote the functional recovery of FAI patients.

Changes in motor unit behaviour across repeated bouts of eccentric exercise.

Unaccustomed eccentric exercise (EE) is protective against muscle damage following a subsequent bout of similar exercise. One hypothesis suggests the existence of an alteration in motor unit (MU) behaviour during the second bout, which might contribute to the adaptive response. Accordingly, the present study investigated MU changes during repeated bouts of EE. During two bouts of exercise where maximal lengthening dorsiflexion (10 repetitions × 10 sets) was performed 3weeks apart, maximal voluntary isometric torque (MVIC) and MU behaviour (quantified using high-density electromyography; HDsEMG) were measured at baseline, during (after set 5), and post-EE. The HDsEMG signals were decomposed into individual MU discharge timings, and a subset were tracked across each time point. MVIC was reduced similarly in both bouts post-EE (Δ27 vs. 23%, P=0.144), with a comparable amount of total work performed (∼1,300 J; P=0.905). In total, 1,754 MUs were identified and the decline in MVIC was accompanied by a stepwise increase in discharge rate (∼13%; P<0.001). A decrease in relative recruitment was found immediately after EE in Bout 1versus baseline (∼16%; P<0.01), along with reductions in derecruitment thresholds immediately after EE in Bout 2. The coefficient of variation of inter-spike intervals was lower in Bout 2 (∼15%; P<0.001). Our data provide new information regarding a change in MU behaviour during the performance of a repeated bout of EE. Importantly, such changes in MU behaviour might contribute, at least in part, to the repeated bout phenomenon.

A Cadaveric Study: Does Ankle Positioning Affect the Quality of Anatomic Syndesmosis Reduction?

The objective of this study was to compare the quality of syndesmotic reduction with the ankle in maximal dorsiflexion versus neutral plantarflexion (normal resting position). Baseline computed tomography (CT) imaging of 10 cadaveric ankle specimens from 5 donors was obtained with the ankles placed in normal resting position. Two fellowship-trained orthopaedic surgeons disrupted the syndesmosis of each ankle specimen. All ankles were then placed in neutral plantarflexion and were subsequently reduced with thumb pressure under direct visualization through an anterolateral approach and stabilized with one 0.062-inch K-wire placed from lateral to medial in a quadricortical fashion across the syndesmosis. Postreduction CT scans were then obtained with the ankle in normal resting position. This process was repeated with the ankles placed in maximal dorsiflexion during reduction and stabilization. Postreduction CT scans were then obtained with the ankles placed in normal resting position. All postreduction CT scans were compared with baseline CT imaging using mixed-effects linear regression with significance set at P < 0.05. Syndesmotic reduction and stabilization in maximal dorsiflexion led to increased external rotation of the fibula compared with baseline scans [13.0 ± 5.4 degrees (mean ± SD) vs. 7.5 ± 2.4 degrees, P = 0.002]. There was a tendency toward lateral translation of the fibula with the ankle reduced in maximal dorsiflexion (3.3 ± 1.0 vs. 2.7 ± 0.7 mm, P = 0.096). No other statistically significant differences between measurements of reduction with the ankle placed in neutral plantarflexion or maximal dorsiflexion compared with baseline were present (P > 0.05). Reducing the syndesmosis with the ankle in maximal dorsiflexion may lead to malreduction with external rotation of the fibula. There was no statistically significant difference in reduction quality with the ankle placed in neutral plantarflexion compared with baseline. Future studies should assess the clinical implications of ankle positioning during syndesmotic fixation.

Intraday Variation of Ankle Dorsiflexion in Short-Track Speed Skaters.

Optimal ankle dorsiflexion range of motion plays a vital role in attaining the essential crouched posture necessary for excelling in speed skating. The purpose of this study was to determine how the ankle dorsiflexion angle evolves throughout a day of training and to identify the factors that influence this angle. Thirty short-track speed skaters, from 2 teams, participated in this study. The maximum ankle dorsiflexion angle was obtained in a lunge position facing a wall, using a digital inclinometer. All measures were obtained 3 times per side, 6 times per day, on 2 training days separated by at least a week. We conducted multiple tests to study the impact of repetition, day, side, team level, sex, and moment on the ankle dorsiflexion angle. The 3 times repeated measures and the 2days of training did not have a significant influence on the results. There was a statistically significant difference between the first time point of the day and the 5 other time points for both ankles. Moreover, the influence of sex and team level was not statistically significant. The results indicate that there are significant changes in ankle dorsiflexion range of motion but only after the first warm-up of the day. Such findings could enable team staff to enhance athletes' precompetition preparation and tailor ankle mobility training regimens more effectively.

Advanced footwear technology and its impacts on running mechanics, running economy and perception of male and female recreational runners

Studies on advanced footwear technology (AFT) often investigate potential performance benefits for constraint populations, and high running speeds. This research compared running biomechanics, running economy and perception between males and females, when wearing three different AFT conditions at recreational running speeds. An innovation shoe sample (IM) at confirmation stage in the product creation process was compared to two commercial running shoes (MM, MF). Gender and shoe variable means were compared for main and interaction effects (p < 0.05) by a mixed 2 × 3 repeated measures analysis of variance (RM ANOVA), and effect size estimation. A main effect was seen for shoe condition, both the IM and MF showed higher vertical loading rates than MM, and higher peak vertical force 1. IM had less frontal plane rearfoot motion than both the MM and MF. At the MTPJ, IM had lower maximum dorsiflexion angle, dorsiflexion velocity leading to lower negative power and negative work than both the MM and MF. IM and MF showed significantly lower oxygen consumption than the MM. Perception measurements showed IM and MF to be significantly softer, responsive and had better propulsion than the MM. A main effect was seen for gender, females exhibited higher vertical loading rates, reduced frontal plane ankle motion and lower MTPJ motion, and lower oxygen consumption compared to males. There was no gender effect for perception. Despite biomechanical differences, both IM and MF showed improved performance compared to the MM. Males and females exhibit different biomechanics when wearing AFT, however this did not lead to differences in subjective perception. It is concluded that the specific AFT applied for IM samples in this research functions for both groups largely similarly.

Effects of radial pressure wave irradiation on triceps surae muscle morphology and function

BackgroundRadial pressure wave (RPW) has been introduced to sports sites as an alternative tool to massage, and there have been reports of irradiating muscles. This study aimed to clarify the effects of RPW irradiation on muscles, focusing on muscle morphology and muscle/fascial elasticity. MethodsThe participants were 23 healthy, able-bodied participants. Muscle morphology (muscle thickness, pinnate angle, muscle fascicle length), muscle and fascia elasticity (deep fascia, subfascial, muscle, deep intermuscular fascia) of the gastrocnemius medial head using ultrasound imaging equipment before and after RPW irradiation intervention. The maximum ankle dorsiflexion range of motion and isometric maximum plantarflexion muscle strength were also measured. ResultsBefore and after RPW irradiation to the triceps surae muscle, muscle thickness, decreased pinnate angle, and increase in maximum ankle dorsiflexion range of motion were observed. No significant changes were observed in muscle fascicle length and maximal isometric plantarflexion strength. In addition, a significant decrease in elasticity was observed in deep fascia, subfascial, and muscle, and the change was particularly large in deep fascia and deep intermuscular fascia. ConclusionIt was suggested that RPW irradiation to muscles might improve fascial gliding and reduce muscle elasticity. It was also found to improve joint range of motion while maintaining muscle output.Trial registration number (Japan Registry of Clinical Trials (jRCT))Current Controlled Trials jRCT1032210104, May 21, 2021.

Comparison of postoperative gait parameters after total ankle arthroplasty and ankle fusion: A systematic review.

Ankle pathology, such as severe arthritis, often necessitates surgical intervention to restore mobility and alleviate pain. Two commonly performed procedures for end-stage ankle disease are ankle fusion (AF) and total ankle arthroplasty (TAA). This review aims to compare the impact of AF and TAA on postoperative gait parameters. An extensive search in PubMed, Scopus, and Web of Science electronic databases was conducted with the use of the keywords ("ankle arthrodesis" OR "ankle fusion") AND ("ankle replacement" OR "ankle arthroplasty") AND "gait." Clinical studies in terms of postoperative gait parameters were included in this review. At least one of the following gait parameters, included in gait analysis, should be researched: spatiotemporal variables and joint kinematics and kinetics. An initial search revealed 221 studies. After the removal of duplicates and screening of titles,10 studies (7 prospective and 3 retrospective case series) were included for qualitative analysis. In the majority of studies, there is no significant difference in spatiotemporal parameters, such as walking speed, cadence, stance duration, step length, and stride length among AF and TAA patients. Postoperative sagittal ankle ROM, mainly maximum ankle dorsiflexion angle is significantly higher in TAA patients, while results concerning hip and knee ROM are variable. The comparison of AF and TAA in terms of postoperative gait parameters has shown variable results. In the majority of studies, there is no significant difference in spatiotemporal and kinetic parameters among AF and TAA patients. Further high-quality prospective studies are needed to fully elucidate the comparison of postoperative gait parameters.

Intrinsic Risk Factors for Lateral Ankle Sprains in Adolescent Soccer Players: A Prospective Cohort Study

Lateral ankle sprain (LAS) is the most common injury in Korean adolescent soccer players. However, intrinsic risk factors for LAS in adolescent soccer players remain unclear. Therefore, this prospective cohort study aimed to identify intrinsic risk factors for LAS in Korean adolescent soccer players. This study included 100 adolescent soccer players (age=13.21±0.95 years, height=1.62±0.09 m, weight=53.37±9.54 kg, BMI-for-age percentile=63.78±20.89%, athletic career=3.95±1.96 years). Baseline measurements were performed in the preseason, and the injury surveillance on LAS was conducted for 1 year. Independent variables included participants’ demographic and anthropometric data, self-reported questionnaire, lower extremity alignments, range of motion, static, and dynamic balance, coordination, and ankle kinematics during running. Independent t-test and Chi-square analysis were used for potential risk factors, which were imported to the binary logistic regression to identify intrinsic risk factors for LAS. Data on intrinsic risk factors identified by the logistic regression were analyzed using the receiver operating characteristic curve analysis to determine a cutoff point of each variable. In this study, age, body mass index, previous LAS history, the number of LAS history, and maximum dorsiflexion and inversion during the stance phase of running were potential risk factors for LAS. Our major findings showed that decreased dorsiflexion and increased inversion at initial contact during running significantly affected LAS occurrence in Korean adolescent soccer players. Considering our major findings, to prevent LAS in adolescent soccer players, gait training must not be overlooked and should be included in warm-up sessions.

Antagonist Activation Measurement in Triceps Surae Using High-Density and Bipolar Surface EMG in Chronic Hemiparesis.

After a stroke, antagonist muscle activation during agonist command impedes movement. This study compared measurements of antagonist muscle activation using surface bipolar EMG in the gastrocnemius medialis (GM) and high-density (HD) EMG in the GM and soleus (SO) during isometric submaximal and maximal dorsiflexion efforts, with knee flexed and extended, in 12 subjects with chronic hemiparesis. The coefficients of antagonist activation (CAN) of GM and SO were calculated according to the ratio of the RMS amplitude during dorsiflexion effort to the maximal agonist effort for the same muscle. Bipolar CAN (BipCAN) was compared to CAN from channel-specific (CsCAN) and overall (OvCAN) normalizations of HD-EMG. The location of the CAN centroid was explored in GM, and CAN was compared between the medial and lateral portions of SO. Between-EMG system differences in GM were observed in maximal efforts only, between BipCAN and CsCAN with lower values in BipCAN (p < 0.001), and between BipCAN and OvCAN with lower values in OvCAN (p < 0.05). The CAN centroid is located mid-height and medially in GM, while the CAN was similar in medial and lateral SO. In chronic hemiparesis, the estimates of GM hyperactivity differ between bipolar and HD-EMGs, with channel-specific and overall normalizations yielding, respectively, higher and lower CAN values than bipolar EMG. HD-EMG would be the way to develop personalized rehabilitation programs based on individual antagonist activations.

Effects of 6 weeks of whole-body vibration training on ankle motor control: a randomized controlled trial.

Interventions on ankle motor control are important to prevent recurrent ankle sprains. Training using whole-body vibration may easily and effectively improve ankle motor control, but the effects have not been investigated. Therefore, this study aimed to clarify the effects of 6 weeks of training with whole-body vibration on ankle motor control in a dynamic movement task among healthy participants. Twenty healthy university students (6 males and 14 females) were randomly allocated to whole-body vibration training and control groups, with 10 participants in each group. The training was performed twice a week for 6 weeks in both groups. Primary outcome was mean ankle angular jerk cost in the star excursion balance test. Secondary outcomes were maximum ankle motion angle and maximum reach distance in the star excursion balance test, ankle proprioception, and range of ankle dorsiflexion motion in the loaded position. There was a significant group × period (pre- and postintervention) interaction for mean ankle angular jerk cost in the direction of ankle abduction/adduction during posterolateral reaching, which was significantly lower at postintervention than that at preintervention in the whole-body vibration group In the whole-body vibration group, the maximum ankle dorsiflexion motion angle during anterior and posterolateral reaching was significantly higher at postintervention than that at preintervention. Training with whole-body vibration improves ankle motor control in dynamic movement tasks, although the direction of reach and plane of motion are limited. Additionally, training with whole-body vibration is also effective in increasing the ankle dorsiflexion angle during dynamic movement tasks.

Impact of plantar flexion resistive moment of dynamic ankle foot orthosis on measures of center of pressure and clinical gait outcomes in individuals with post-stroke hemiparesis

BackgroundAn ankle-foot orthosis (AFO) with plantar flexion resistance (PFR) can improve the first rocker function during gait, but the incremental changes in the resistive moment on balance and gait have not been well identified. ObjectivesTo investigate the effect of changing the PFR moment of dynamic AFO (DAFO) on measures of the center of pressure (COP) and clinical gait outcomes in individuals with post-stroke hemiparesis. MethodIn this randomized repeated measure study of 36 stroke individuals, the customized DAFO using foot drop ankle units set in three PFR situations (low, medium, and high) was evaluated. The balance parameters for COP measures were investigated by HUMAC® Balance & Tilt System. Gait parameters and ankle kinematics were recorded using the 3D motion analysis through force platform and optoelectronic system. The comparison was made using a parametric ANOVA test and the P value was set at 0.05 for statistical significance. ResultsSignificant differences were observed for COP average velocity (1.30 ± 0.64, 1.10 ± 0.05, and 1.37 ± 0.43), COP path length (43.3 ± 4.6, 33.4 ± 4.3, and 36.3 ± 5.4), walking velocity (11.0 ± 3.1, 13.2 ± 4.4, and 9.9 ± 3.5), and cadence (31.5 ± 2.0, 33.0 ± 3.1, and 29.0 ± 1.6) respectively for low, medium and high PFR settings (P < 0.05). Except for the COP path length and cadence, posthoc multiple comparisons revealed significant differences between low and medium (P < 0.05) and medium and high (P < 0.05) PFR grades. PFR with medium resistance demonstrated near-normal maximal peak ankle dorsiflexion (mean deviation of 8 degrees, P < 0.05). ConclusionMedium PFR grade should be encouraged since it can enhance balance parameters like path length and average velocity of COP, increase cadence and average velocity during gait, and improve maximal peak ankle dorsiflexion.

Effect of 6-Week Instrument-Assisted Soft Tissue Mobilization on Joint Flexibility and Musculotendinous Properties.

Instrument-assisted soft tissue mobilization (IASTM) stimulates soft subcutaneous tissues by applying pressure to the skin with a specialized bar or spurtle-like instrument. No studies have verified whether several weeks of continuous IASTM alone can alter joint flexibility and musculotendinous properties in healthy participants. We examined the effect of a 6-week IASTM program on joint flexibility and the musculotendinous properties of the lower limbs. Fourteen healthy men (aged 19-35 years) who participated in a 6-week IASTM program (3 days weekly) for the soft tissue of the posterior aspect of one lower leg were included. The other leg served as the control. Before and after the intervention, we measured the maximal ankle joint dorsiflexion angle (dorsiflexion range of motion: DFROM) and maximal passive torque (MPT), a measure of stretch tolerance. We measured muscle and tendon stiffness using shear wave elastography on the gastrocnemius and Achilles tendon. IASTM significantly increased the DFROM and MPT (p < 0.05 for both). However, no significant changes were observed in muscle and tendon stiffness. None of the parameters changed significantly in the control group. The 6-week IASTM program increased stretch tolerance and joint flexibility but did not change muscle and tendon stiffness.

Shear-Wave Elastography of the Achilles tendon: reliability analysis and impact of parameters modulating elasticity values.

Shear wave elastography (SWE) has seen many advancements in Achilles tendon evaluation in recent years, yet standardization of this technique is still problematic due to the lack of knowledge regarding the optimal way to perform the examination. The purpose of this study was to evaluate the effects of ankle position, probe frequency and physical effort on the shear modulus of the Achilles tendon, but also to determine the intra and inter-observer reliability of the technique. 37 healthy volunteers were included; SWE protocol was performed by two examiners. We analyzed the shear modulus of the tendon with the ankle in neutral, maximum dorsiflexion and maximum plantar flexion using two different high frequency probes. Afterwards, the subjects performed a brief physical exercise and SWE measurements were repeated. The L18-5 probe showed the highest ICC values (ICC = 0.798, 95% CI 0.660-0.880, p < 0.001) when positioned at 2cm from the calcaneal insertion with the ankle in a neutral state. Conversely, utilizing the same L18-5 probe at 1cm from the insertion during maximum plantar flexion of the ankle resulted in the lowest ICC (ICC = 0.422, 95% CI 0.032-0.655, p = 0.019). Significant variations in elasticity values were noted among different ankle positions and probe types, while no significant changes in elasticity were observed post-physical exercise. Ankle position and probe frequency are factors that influence elasticity values of the Achilles tendon. An ankle position between 10 and 20 degrees of plantar flexion is the most suitable for SWE evaluation. However, more research focusing on Achilles tendon SWE is essential due to the challenges encountered in standardizing this region.

The calcaneofibular ligament groove at the inferior fibula, an ultrasonographic anatomical landmark.

Calcaneofibular ligament (CFL) injuries are harder to diagnose than anterior talofibular ligament (ATFL) ones. This study aimed to clarify the fibular attachment of the CFL and verify the bony landmark for evaluating the CFL on ultrasonography. Fifty-nine ankles were used in this anatomical study. To confirm the control function of the CFL, we performed passive movement manually using cadaveric ankles and observed the ankle positions where the CFLs were tense. Histological observation of CFL attachment of the fibula was performed using Masson's trichrome stain. The ATFL and CFL were removed, and the bone morphology of the CFL attachment and inferior fibular end was imaged using a stereomicroscope and a 3D scanner. Using ultrasonography, we evaluated the bone morphology of the fibular attachment of the CFL in short-axis images of 27 healthy adult ankles. The CFL was tensed according to ankle motions: supination, maximum dorsi flexion, maximum plantar flexion, and mild plantar flexion-external rotation. Below the CFL attachment of the fibula was a slight groove between the inferior tip and the obscure tubercle of the fibula. This groove was observed in 81.5% of cases using short-axis ultrasonography. The CFL was tensed in various ankle positions to control the movements of the talocrural and subtalar joints. There was a slight groove at the inferior end of the fibula where the CFL coursed downward. We called it the CFL groove and proposed that it could serve as a landmark for the short-axis image of ultrasonography.

The Effects of 5 Minutes of Static Stretching on Joint Flexibility and Muscle Strength Are Comparable Between Ballet Dancers and Non-Dancers.

Introduction: Ballet dancers have a special morphology, such as a large muscle thickness that affects passive torque. Ballet dancers also possess specialized mechanical, and neural properties of muscles and tendons. These characteristics may produce different static stretching effects than non-dancers. Therefore, this study aimed to determine the differences in the effects of static stretching on joint range of motion, passive torque, and muscle strength between ballet dancers and non-dancers. Methods: This study included 13 ballet dancers and 13 college students. The muscle and tendon thicknesses were assessed using ultrasonography. In the right lower extremity, torque-angle data and muscle-tendon junction displacement measurements were obtained during isokinetic passive dorsiflexion before and after a 5-minute static stretch against the right plantar flexors. The relative stretching intensity was calculated by dividing the stretching angle by the maximal dorsiflexion angle pre-stretch. Additionally, the isometric maximal voluntary plantar flexion torque on the left ankle was measured before and after 5 minutes of static stretching against the left plantar flexors. Results: Ballet dancers had significantly greater muscle thickness than non-dancers (22.4 ± 2.2 vs 18.1 ± 1.7 mm), whereas no significant difference was observed in the Achilles tendon thickness. No significant difference was observed in the stretching angle; however, the relative stretching intensity was higher in the control group (65.9 ± 19.8 vs 127.5 ± 63.8%). Static stretching increased the maximal dorsiflexion angle (dancer: 30.4° ± 9.6° to 33.9° ± 9.5°, non-dancer: 18.4° ± 8.6° to 20.5° ± 9.5°) and maximal passive torque in both groups, whereas the maximal isometric plantar flexion torque and submaximal passive torque decreased. However, no significant differences were observed in the changes between the groups. Conclusion: These results indicate that despite having a lower relative stretching intensity, ballet dancers experienced similar changes as non-dancers after 5 minutes of static stretching.

Discrepancies Between Intraoperative and Postoperative Ankle Motion Measured for Anterior-Approach Total Ankle Arthroplasty.

Although intraoperative ankle motion serves as a foundational reference for anticipated motion after surgery and guides the addition of procedures to enhance ankle motion in total ankle arthroplasty (TAA), the relationship between intraoperative and postoperative ankle motion remains unclear. This study aimed to investigate the discrepancy between intraoperative and postoperative ankle range of motion (ROM) following TAAs using the anterior-approach, fixed-bearing systems. This study retrospectively reviewed 67 patients (67 ankles) who underwent primary TAA at a single institution. Three different types of anterior-approach, fixed-bearing TAA systems were included. Intraoperative fluoroscopy was used to document the maximal dorsiflexion and plantar flexion at the end of the case. Standardized weightbearing maximum dorsiflexion and plantar flexion sagittal radiographs were obtained pre- and postoperatively, following a previously described method. The motion between 3 different time points (preoperative, intraoperative, and postoperative [mean 11.4 months]) was compared using pairwise t tests, and their differences were quantified. The mean total tibiotalar ROM was 38.1 degrees (SD 7.8) intraoperatively, and the postoperative total tibiotalar ROM was 24.2 degrees (SD 9.7) (P < .001), indicating that a mean of 65.3% (SD 26.7) of the intraoperative motion was maintained postoperatively. Intraoperative dorsiflexion (mean 11.6 [SD 4.5] degrees) showed no evidence of difference from postoperative dorsiflexion (mean 11.4 [SD 5.8] degrees, P > .99), indicating that a median of 95.6% (interquartile range: 66.2-112) of the intraoperative maximum dorsiflexion was maintained postoperatively. However, there was a significant difference between intraoperative plantarflexion (mean 26.4 [SD 6.3]) and postoperative plantarflexion (12.8 [SD 6.9] degrees, P < .001), indicating a mean 50.6% (SD 29.6) of intraoperative motion maintained in the postoperative assessment. There was an improvement of 2.5 degrees in the total tibiotalar ROM following TAA with statistical significance (P < .043). This study revealed a significant difference between intraoperative ankle ROM and ankle ROM approximately 1 year after anterior-approach, fixed-bearing TAA, mainly due to plantarflexion motion restriction. Minimal difference in dorsiflexion suggests the importance of achieving the desired postoperative dorsiflexion motion during the surgery using the best possible adjunct procedures. Level IV, case series.

Serious Game with Electromyography Feedback and Physical Therapy in Young Children with Unilateral Spastic Cerebral Palsy and Equinus Gait: A Prospective Open-Label Study.

The clinical effects of a serious game with electromyography feedback (EMGs_SG) and physical therapy (PT) was investigated prospectively in children with unilateral spastic cerebral palsy (USCP). An additional aim was to better understand the influence of muscle shortening on function. Thirty children with USCP (age 7.6 ± 2.1 years) received four weeks of EMGs_SG sessions 2×/week including repetitive, active alternating training of dorsi- and plantar flexors in a seated position. In addition, each child received usual PT treatment ≤ 2×/week, involving plantar flexor stretching and command strengthening on dorsi- and plantar flexors. Five-Step Assessment parameters, including preferred gait velocity (normalized by height); plantar flexor extensibility (XV1); angle of catch (XV3); maximal active ankle dorsiflexion (XA); and derived coefficients of shortening, spasticity, and weakness for both soleus and gastrosoleus complex (GSC) were compared pre and post treatment (t-tests). Correlations were explored between the various coefficients and gait velocities at baseline. After four weeks of EMGs_SG + PT, there was an increase in normalized gait velocity from 0.72 ± 0.13 to 0.77 ± 0.13 m/s (p = 0.025, d = 0.43), a decrease in coefficients of shortening (soleus, 0.10 ± 0.07 pre vs. 0.07 ± 0.08 post, p = 0.004, d = 0.57; GSC 0.16 ± 0.08 vs. 0.13 ± 0.08, p = 0.003, d = 0.58), spasticity (soleus 0.14 ± 0.06 vs. 0.12 ± 0.07, p = 0.02, d = 0.46), and weakness (soleus 0.14 ± 0.07 vs. 0.11 ± 0.07, p = 0.005, d = 0.55). At baseline, normalized gait velocity correlated with the coefficient of GSC shortening (R = -0.43, p = 0.02). Four weeks of EMGs_SG and PT were associated with improved gait velocity and decreased plantar flexor shortening. A randomized controlled trial comparing EMGs_SG and conventional PT is needed.

Differences and relationships between weightbearing and non-weightbearing dorsiflexion range of motion in foot and ankle injuries

BackgroundThis study aimed to: (1) identify assessment methods that can detect greater ankle dorsiflexion range of motion (DROM) limitation in the injured limb; (2) determine whether differences in weightbearing measurements exist even in the absence of DROM limitations in the injured limb according to non-weightbearing measurements; and (3) examine associations between DROM in the weightbearing and non-weightbearing positions and compare those between a patient group with foot and ankle injuries and a healthy group.MethodsEighty-two patients with foot and ankle injuries (e.g., fractures, ligament and tendon injuries) and 49 healthy individuals participated in this study. Non-weightbearing DROM was measured under two different conditions: prone position with knee extended and prone position with knee flexed. Weightbearing DROM was measured as the tibia inclination angle (weightbearing angle) and distance between the big toe and wall (weightbearing distance) at maximum dorsiflexion. The effects of side (injured, uninjured) and measurement method on DROM in the patient groups were assessed using two-way repeated-measures ANOVA and t-tests. Pearson correlations between measurements were assessed. In addition, we analyzed whether patients without non-weightbearing DROM limitation (≤ 3 degrees) showed limitations in weightbearing DROM using t-tests with Bonferroni correction.ResultsDROM in patient groups differed significantly between legs with all measurement methods (all: P < 0.001), with the largest effect size for weightbearing angle (d = 0.95). Patients without non-weightbearing DROM limitation (n = 37) displayed significantly smaller weightbearing angle and weightbearing distance on the injured side than on the uninjured side (P < 0.001 each), with large effect sizes (d = 0.97–1.06). Correlation coefficients between DROM in non-weightbearing and weightbearing positions were very weak (R = 0.17, P = 0.123) to moderate (R = 0.26–0.49, P < 0.05) for the patient group, and moderate to strong for the healthy group (R = 0.51–0.69, P < 0.05).ConclusionsDROM limitations due to foot and ankle injuries may be overlooked if measurements are only taken in the non-weightbearing position and should also be measured in the weightbearing position. Furthermore, DROM measurements in non-weightbearing and weightbearing positions may assess different characteristics, particularly in patient group.Level of evidenceLevel IV, cross-sectional study.

Defining and Differentiating Congenital Vertical Talus and Congenital Oblique Talus: It's Not Primarily About the Talus.

Congenital vertical talus (CVT) and congenital oblique talus (COT) are rocker-bottom foot deformities that have similar names and no objective definitions. This has led to confusion for practitioners, as well as scientific challenges for researchers. Our goal was to provide objective radiographic criteria to define and differentiate CVT and COT. We evaluated 62 pairs of maximum dorsiflexion and plantar flexion lateral radiographs of infant feet that had been clinically diagnosed with CVT. The dorsiflexion tibiotalar angle, the plantar flexion talus-first metatarsal angle, and the plantar flexion foot center of rotation of angulation (foot-CORA) were measured using transparent overlay tools. Freehand measurements were made on a subset of 10 pairs of radiographs to confirm clinical applicability. Nine contralateral pairs of radiographs of normal feet were measured for comparison. Specific values for the radiographic measurements were identified that, together, reliably differentiated the shapes of rocker-bottom feet with CVT, COT, and flexible flatfoot with a short tendo-Achilles (FFF-STA), as well as the shape of the normal foot. More severe and rigid rocker-bottom foot deformities were diagnosed with CVT. Less severe and more flexible deformities were diagnosed with COT. CVT, COT, FFF-STA, and normal feet can be reliably differentiated using 2 angular measurements and 1 bone position measurement on dorsiflexion and plantar flexion lateral radiographs. Our data indicated that the differentiation of CVT and COT is based primarily on the rigidity of the navicular dislocation rather than the verticality of the talus. The data further supported the proposition that COT is a foot deformity along a spectrum of valgus/eversion deformities of the hindfoot that requires early treatment. Application of these diagnostic criteria should lead to clinical studies that identify a specific treatment, treatment outcome, and prognosis for each deformity. Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.