Ankle Plantarflexion Angle Research Articles

The relationship between performance and biomechanics in middle-distance runners

ABSTRACT The present study aimed to identify movement patterns most related to running performance among highly trained middle-distance runners. Eleven male runners performed overground running trials on an indoor running track, and three-dimensional analyses techniques were used to measure running kinematics and kinetics. Performance was measured as season and personal best time over 1500 m. The average velocity during the running trials was 7.2 ± 0.3 m/s. The average season and personal best 1500 m race times were 3:49.7 ± 0:05.8 and 3:46.0 ± 0:08.3 minutes, respectively. Regression analysis revealed that a smaller range of sagittal-plane hip motion during swing, less thorax flexion at toe-off and a smaller ankle plantarflexion angle at contact accounted for 95.7% (p < 0.001) of the variation in season best running performance. Less sagittal-plane hip motion during swing and a smaller ankle plantarflexion angle at contact also explained 79% of the variance in personal best time. Slower middle-distance runners make initial ground contact with a more plantarflexed ankle and greater forward lean of the trunk. We recommend that coaches and runners pay attention to ankle, shank and thorax angles during technical development and training to identify opportunities to optimise middle-distance running mechanics and performance.

Paralysis of the gastrocnemius medial head differentially affects gait patterns and muscle activity during level and stair ascent locomotion

BackgroundPrior studies have analyzed the activity of the gastrocnemius (GCM) medial and lateral heads as a single unit because it is technically challenging to separately analyze the function of each component in vivo. However, functional variation between the medial and lateral heads is expected due to their anatomical differences. Research questionWhat is the independent function of the medial GCM? How does paralysis of the GCM medial head affect gait kinematics?. MethodsTwelve healthy adults (two males and ten females; age: 28.2 [±7.72] years) that were scheduled to undergo neurolysis of the tibial nerve branch supplying the medial head of the GCM for aesthetic calf reduction participated in the study. Gait analysis was performed using a computerized opto-electric gait analysis system to measure kinematic data. Surface electromyography (EMG) was recorded simultaneously during the gait analysis. Surface electrodes were placed on seven muscles. Pre-procedure and 1-week and 3-month post-procedure data were compared using a linear mixed model. ResultsDuring level walking, decreased activity of the GCM medial head did not significantly change gait kinematics. However, a significant increase in GCM lateral head and hamstring activities occurred after a branch nerve block to the GCM medial head. During stair ascent, in contrast to level walking, changes in EMG activity only occurred in the GCM medial head, and post-procedure ankle dorsiflexion angles at the end of the terminal-stance phase significantly increased. Ankle plantarflexion angles during the push-off phase were also decreased when compared with pre-procedure values. SignificanceThe human body response to dysfunction of the GCM medial head depended on the type of locomotion.

Mid-flight trunk flexion and extension altered segment and lower extremity joint movements and subsequent landing mechanics

ObjectivesTo assess the effect of mid-flight trunk flexion and extension on the movements of body segments and lower extremity joints and subsequent landing mechanics during a jump-landing task. DesignParticipants performed three jump-landing conditions in a randomized order. MethodsForty-one participants completed jump-landing trials when performing three different mid-flight trunk motion: reaching forward, reaching up, and reaching backward. Whole-body kinematic and ground reaction force data were collected. ResultsThe reaching backward condition resulted in a more posteriorly positioned upper body center of mass (COM) and more anteriorly positioned pelvis COM, legs COM, hip, and knee joint positions relative to the whole-body COM in flight and at initial contact of landing. The reaching backward condition showed the least hip flexion and ankle plantarflexion angles at initial contact as well as the least hip and knee flexion angles and the greatest ankle dorsiflexion angles at 100ms after landing. The reaching backward condition also demonstrated the greatest peak posterior ground reaction forces, peak and average knee extension moments, peak and average hip flexion moments, and peak knee varus moments within the first 100ms after landing. Opposite changes were observed for the reaching forward condition. ConclusionsMid-flight trunk extension resulted in body postures that predisposed individuals to land with increased knee extension and varus moments and decreased knee flexion angles, which are indirectly associated with increased ACL loading. These findings may help to understand altered trunk motion during certain ACL injury events and provide information for developing jump-landing training strategies.

Combination Effects of Sensorimotor Training and Transcranial Direct Current Stimulation on Balance Ability in Soccer Players

Background/Objectives: The purpose of the present study was to investigate the effects of sensorimotor training and transcranial direct current stimulation (tDCS) on changes in proprioception and static and dynamic balance in soccer players. Methods/Statistical analysis: Ten soccer players with at least 5 years of experience playing soccer participated in the study. The players were randomly assigned to group I (n=5, only sensorimotor training) and group II (n=5, both sensorimotor training and tDCS). Each group underwent training once a day for 5 days. Proprioception was assessed using 4D-MT, while balance ability was assessed using BIO Rescue. Assessments were performed before, immediately after, and 5 days after a match. Finding: The comparison results with regard to proprioception (reproduction of ankle dorsiflexion and plantar flexion angles), static balance ability (surface area ellipse), and dynamic balance ability (limits of stability in forward, backward, and whole directions) confirmed that group II had a greater recovery to pre match levels in comparison to group I. Improvements/Applications: For soccer players who need to recover quickly after a vigorous soccer match, applying tDCS together with sensorimotor training can have a positive effect on improving proprioception and balance ability.

Speed-adaptive control of functional electrical stimulation for dropfoot correction

BackgroundFunctional electrical stimulation is an important therapy technique for dropfoot correction. In order to achieve natural control, the parameter setting of FES should be associated with the activation of the tibialis anterior.MethodsThis study recruited nine healthy subjects and investigated the relations of walking speed with the onset timing and duration of tibialis anterior activation. Linear models were built for the walking speed with respect to these two parameters. Based on these models, the speed-adaptive onset timing and duration were applied in FES-assisted walking for nine healthy subjects and ten subjects with dropfoot. The kinematic performance of FES-assisted walking triggered by speed-adaptive stimulation were compared with those triggered by the heel-off event, and no-stimulation walking at different walking speeds.ResultsHigher ankle dorsiflexion angle was observed in heel-off stimulation and speed-adaptive stimulation conditions than that in no-stimulation walking condition at all the speeds. For subjects with stroke, the ankle plantarflexion angle in speed-adaptive stimulation condition was similar to that in no-stimulation walking condition, and it was significant larger than that in heel-off stimulation condition at all speeds.ConclusionsThe improvement in ankle dorsiflexion without worsening ankle plantarflexion in speed-adaptive stimulation condition could be attributed to the appropriate stimulation timing and duration. These results provide evidence that the proposed stimulation system with speed-related parameters is more physiologically appropriate in dropfoot correction, and it may have great potential value in future clinical applications.Trial registrationMedical Ethics Committee of Guangdong Work Injury Rehabilitation Center, AF/SC-07/2016.22. Registered 26 May 2016.

Hip-abductor fatigue influences sagittal plane ankle kinematics and shank muscle activity during a single-leg forward jump

Diminished hip abductor strength decreases postural control which is a parameter that is associated with an increased risk of ankle sprains. In our study we evaluated the influence of hip abductor fatigue on sagittal plane ankle kinematics and shank muscle activity during a single-leg forward jump. Sagittal ankle plane kinematics are important in ankle sprains but less studied than frontal plane kinematics. Therefore, we evaluated differences in sagittal ankle kinematics (12-camera motion capture system) and lower limb surface electromyographic muscle activity in 20 healthy, recreationally active adults (9 females, 11 males, mean age 30.3 SD 4.0 years, mean BMI 23.6 SD 2.8 kg/m2) before and after a hip abductor fatigue protocol (200-ms prior, at and in the 250-ms following initial contact (IC)).After fatigue, the maximal ankle plantar-flexion angle decreased prior to IC (median 3.8° [interquartile range 0.1, 7.2], p = 0.014), at IC (4.1° [−0.3, 5.0], p = 0.027) and post IC (4.1° [−1.3, 5.0] p = 0.036). Gastrocnemius activity onset was delayed (−28.0 ms [−44.0, 0.0], p < 0.01). Average activity of the tibialis anterior increased prior to IC (pre-fatigue 19.32% [14.89, 33.45], post-fatigue 28.95% [18.49, 34.81], p < 0.05).Hip-abductor fatigue influenced sagittal ankle kinematics and shank muscle activity during single-leg landings.

Intensity- and Duration-Adaptive Functional Electrical Stimulation Using Fuzzy Logic Control and a Linear Model for Dropfoot Correction.

Functional electrical stimulation (FES) is important in gait rehabilitation for patients with dropfoot. Since there are time-varying velocities during FES-assisted walking, it is difficult to achieve a good movement performance during walking. To account for the time-varying walking velocities, seven poststroke subjects were recruited and fuzzy logic control and a linear model were applied in FES-assisted walking to enable intensity- and duration-adaptive stimulation (IDAS) for poststroke subjects with dropfoot. In this study, the performance of IDAS was evaluated using kinematic data, and was compared with the performance under no stimulation (NS), FES-assisted walking triggered by heel-off stimulation (HOS), and speed-adaptive stimulation. A larger maximum ankle dorsiflexion angle in the IDAS condition than those in other conditions was observed. The ankle plantar flexion angle in the IDAS condition was similar to that of normal walking. Improvement in the maximum ankle dorsiflexion and plantar flexion angles in the IDAS condition could be attributed to having the appropriate stimulation intensity and duration. In summary, the intensity- and duration-adaptive controller can attain better movement performance and may have great potential in future clinical applications.

Correlation of Transtibial Prosthetic Alignment Quality and Step-by-Step Variance of Gait

ABSTRACT Introduction The quality of lower-limb prosthetic alignment cannot easily be measured directly but may be described by its effects on gait comfort and efficiency. It is known that gait stability and step variability are correlated, as are gait stability and prosthetic alignment. This study investigated the hypothesis that prosthetic alignment and step variability are correlated. This would have the implication that step variability can be measured to assess the quality of prosthetic alignment (and possibly other relevant factors such as prosthetic fit and componentry selection). Materials and Methods Twelve experienced users of transtibial prostheses were subjected to a protocol that introduced malalignments of their prosthetic ankle plantarflexion angle in a randomized crossover design. Perceived alignment quality was recorded via a visual analog scale. Step-by-step variability in horizontal ground reaction forces and axial ankle torsion moment was measured using a prosthesis-integrated load cell and was statistically compared with the degree of misalignment by bivariate correlation analysis. Results Findings suggest that variance in axial torsion moment and step duration may be correlated to alignment quality. Conclusions Subjective patient feedback is the recommendable criterion for alignment assessment in active and experienced users of prostheses. Further research is recommended before step variance may help assess prosthetic alignment quality in patients with less experience in prosthetic use.

Running quietly reduces ground reaction force and vertical loading rate and alters foot strike technique

ABSTRACTThis study aimed to determine if a quantifiable relationship exists between the peak sound amplitude and peak vertical ground reaction force (vGRF) and vertical loading rate during running. It also investigated whether differences in peak sound amplitude, contact time, lower limb kinematics, kinetics and foot strike technique existed when participants were verbally instructed to run quietly compared to their normal running. A total of 26 males completed running trials for two sound conditions: normal running and quiet running. Simple linear regressions revealed no significant relationships between impact sound and peak vGRF in the normal and quiet conditions and vertical loading rate in the normal condition. t-Tests revealed significant within-subject decreases in peak sound, peak vGRF and vertical loading rate during the quiet compared to the normal running condition. During the normal running condition, 15.4% of participants utilised a non-rearfoot strike technique compared to 76.9% in the quiet condition, which was corroborated by an increased ankle plantarflexion angle at initial contact. This study demonstrated that quieter impact sound is not directly associated with a lower peak vGRF or vertical loading rate. However, given the instructions to run quietly, participants effectively reduced peak impact sound, peak vGRF and vertical loading rate.

Reduction of genu recurvatum through adjustment of plantarflexion resistance of an articulated ankle-foot orthosis in individuals post-stroke

BackgroundGenu recurvatum (knee hyperextension) is a common issue for individuals post-stroke. Ankle-foot orthoses are used to improve genu recurvatum, but evidence is limited concerning their effectiveness. Therefore, the aim of this study was to investigate the effect of changing the plantarflexion resistance of an articulated ankle-foot orthosis on genu recurvatum in patients post-stroke. MethodsGait analysis was performed on 6 individuals post-stroke with genu recurvatum using an articulated ankle-foot orthosis whose plantarflexion resistance was adjustable at four levels. Gait data were collected using a Bertec split-belt instrumented treadmill in a 3-dimensional motion analysis laboratory. Gait parameters were extracted and plotted for each subject under the four plantarflexion resistance conditions of the ankle-foot orthosis. Gait parameters included: a) peak ankle plantarflexion angle, b) peak ankle dorsiflexion moment, c) peak knee extension angle and d) peak knee flexion moment. A non-parametric Friedman test was performed followed by a post-hoc Wilcoxon Signed-Rank test for statistical analyses. FindingsAll the gait parameters demonstrated statistically significant differences among the four resistance conditions of the AFO. Increasing the amount of plantarflexion resistance of the ankle-foot orthosis generally reduced genu recurvatum in all subjects. However, individual analyses showed that the responses to the changes in the plantarflexion resistance of the AFO were not necessarily linear, and appear unique to each subject. InterpretationsThe plantarflexion resistance of an articulated AFO should be adjusted to improve genu recurvatum in patients post-stroke. Future studies should investigate what clinical factors would influence the individual differences.

Effects of Prophylactic Knee Bracing on Lower Limb Kinematics, Kinetics, and Energetics During Double-Leg Drop Landing at 2 Heights

Background: Anterior cruciate ligament (ACL) injuries commonly occur during landing maneuvers. Prophylactic knee braces were introduced to reduce the risk of ACL injuries, but their effectiveness is debated. Hypotheses: We hypothesized that bracing would improve biomechanical factors previously related to the risk of ACL injuries, such as increased hip and knee flexion angles at initial contact and at peak vertical ground-reaction force (GRF), increased ankle plantar flexion angles at initial contact, decreased peak GRFs, and decreased peak knee extension moment. We also hypothesized that bracing would increase the negative power and work of the hip joint and would decrease the negative power and work of the knee and ankle joints. Study Design: Controlled laboratory study. Methods: Three-dimensional motion and force plate data were collected from 8 female and 7 male recreational athletes performing double-leg drop landings from 0.30 m and 0.60 m with and without a prophylactic knee brace. GRFs, joint angles, moments, power, and work were calculated for each athlete with and without a knee brace. Results: Prophylactic knee bracing increased the hip flexion angle at peak GRF by 5.56° (P < .001), knee flexion angle at peak GRF by 4.75° (P = .001), and peak hip extension moment by 0.44 N·m/kg (P < .001). Bracing also increased the peak hip negative power by 4.89 W/kg (P = .002) and hip negative work by 0.14 J/kg (P = .001) but did not result in significant differences in the energetics of the knee and ankle. No differences in peak GRFs and peak knee extension moment were observed with bracing. Conclusion: The application of a prophylactic knee brace resulted in improvements in important biomechanical factors associated with the risk of ACL injuries. Clinical Relevance: Prophylactic knee braces may help reduce the risk of noncontact knee injuries in recreational and professional athletes while playing sports. Further studies should investigate different types of prophylactic knee braces in conjunction with existing training interventions so that the sports medicine community can better assess the effectiveness of prophylactic knee bracing.

Ankle Bracing Decreases Vertical Jump Height and Alters Lower Extremity Kinematics

The purpose of this study was to determine the effects of ankle bracing on vertical jump performance and lower extremity kinematics and electromyography (EMG) activity. Twenty healthy college athletes participated in two sessions, separated by a minimum of 24 hr. They performed five jumps with no brace on the first day, and five jumps with both ankles braced on the second day. An average of the three highest jumps each day was used for analysis. Braced vertical jump performance significantly decreased (p = .002) as compared with the unbraced condition. In addition, hip flexion (p = .043) and ankle plantar flexion (p = .001) angles were significantly smaller during the braced vertical jump. There was also a significant reduction in soleus muscle EMG (p = .002) during the braced condition.

下肢関節の屈曲拘縮が立位姿勢の関節角度と関節モーメントに及ぼす影響：力学シミュレーション研究

The purpose of this study is to clarify the effect of hip, knee, and ankle joint contractures on the joint angle and joint moment during standing posture using a mechanics simulation. A two-dimensional segment model (trunk, thighs, shanks, and feet) was created, and the standing postures for various hip, knee, and ankle joint angle configurations were generated (i.e. 743 types of standing postures). The hip, knee, and ankle joint contractures were reproduced by manipulating the joint stiffness, and optimal standing posture when the minimum value of the sum of muscle activities was obtained. When the hip joint contracture was developed during standing posture, the hip and knee flexion angle, and the hip and knee extension moment increased as well. When the knee joint contracture was developed during standing posture, the hip and knee flexion angle, ankle dorsiflexion angle, and the knee extension moment increased. When the ankle joint contracture was developed during standing posture, the hip flexion angle and the ankle plantarflexion angle increased and the knee joint was extended; the hip extension moment and knee flexion moment also increased. The findings of this study may help to improve abnormal standing posture through physical therapy.

The effect of changing plantarflexion resistive moment of an articulated ankle–foot orthosis on ankle and knee joint angles and moments while walking in patients post stroke

BackgroundThe adjustment of plantarflexion resistive moment of an articulated ankle–foot orthosis is considered important in patients post stroke, but the evidence is still limited. Therefore, the aim of this study was to investigate the effect of changing the plantarflexion resistive moment of an articulated ankle–foot orthosis on ankle and knee joint angles and moments in patients post stroke. MethodsGait analysis was performed on 10 subjects post stroke under four different plantarflexion resistive moment conditions using a newly designed articulated ankle–foot orthosis. Data were recorded using a Bertec split-belt instrumented treadmill in a 3-dimensional motion analysis laboratory. FindingsThe ankle and knee sagittal joint angles and moments were significantly affected by the amount of plantarflexion resistive moment of the ankle–foot orthosis. Increasing the plantarflexion resistive moment of the ankle–foot orthosis induced significant decreases both in the peak ankle plantarflexion angle (P<0.01) and the peak knee extension angle (P<0.05). Also, the increase induced significant increases in the internal dorsiflexion moment of the ankle joint (P<0.01) and significantly decreased the internal flexion moment of the knee joint (P<0.01). InterpretationThese results suggest an important link between the kinematic/kinetic parameters of the lower-limb joints and the plantarflexion resistive moment of an articulated ankle–foot orthosis. A future study should be performed to clarify their relationship further so that the practitioners may be able to use these parameters as objective data to determine an optimal plantarflexion resistive moment of an articulated ankle–foot orthosis for improved orthotic care in individual patients.

Changes in Gait Detected by Three-Dimensional Motion Analysis in Patients with Acoustic Neuroma

Many patients with acoustic neuroma experience hearing loss, tinnitus, and equilibrium disturbance. Gait studies performed using tactile sensors placed under the feet have indicated that an acoustic neuroma causes unstable gait, even though this cannot be detected by visual observation. Three-dimensional motion analysis is a useful tool to assess gait. The purpose of this study was to use a three-dimensional motion analysis system to quantify the spatiotemporal and kinematic parameters of gait in patients with acoustic neuroma. Seventeen patients with unilateral acoustic neuroma and seven age-, height-, and foot-sizematched healthy subjects participated. Subjects were asked to walk 4 meters in eyes-open and eyes-closed conditions. Gait speed, stride length, stride duration, head movements in the vertical direction and yaw, pitch, and roll dimensions, gait deviation, forefoot motion, and ankle plantar flexion angle at heel strike were quantified. Patients with acoustic neuroma had slower gait with wider step width and shorter stride length along with greater head movement in pitch and roll than controls. In addition, patients with acoustic neuroma had lower ankle plantar flexion angle at heel strike than controls, especially in the eyes-closed condition. These characteristics of gait increase our understanding of the pathophysiological changes caused by acoustic neuroma.

Effect of a combined inversion and plantarflexion surface on ankle kinematics and EMG activities in landing

PurposeThe purpose of this study was to examine the effects of landing on a combined inversion and plantarflexion surface on the ankle kinematics and electromyographic (EMG) activities of medial gastrocnemius (MG), peroneus longus (PL), and tibialis anterior (TA) muscles. MethodsTwelve recreational athletes performed five drop landings from an overhead bar of 30 cm height on to three surfaces: a flat surface, a 25° inversion surface, and a combined surface of 25° inversion and 25° plantarflexion. The kinematic variables and integrated EMG (IEMG) of the three muscles were assessed using a one-way repeated measures ANOVA and a 3 × 3 (surface × muscle) ANOVA, respectively (p < 0.05). ResultsThe IEMG results showed a significant muscle by surface interaction. The flat surface induced higher TA activity than the two tilted surfaces. The inverted surface produced significantly higher inversion peak angle and velocity than the flat surface, but similar PL activity across the surfaces. The MG IEMG, ankle plantarflexion angle, and inversion range of motion were significantly higher for the combined surface compared to the inverted surface. ConclusionThese findings suggest that compared to the inversion surface, the combined plantarflexion and inversion surface seems to provide a more unstable surface condition for lateral ankle sprains during landing.

Shoe drop has opposite influence on running pattern when running overground or on a treadmill.

Minimalist running shoes are designed to induce a foot strike made more with the forepart of the foot. The main changes made on minimalist shoe consist in decreasing the height difference between fore and rear parts of the sole (drop). Barefoot and shod running have been widely compared on overground or treadmill these last years, but the key characteristic effects of minimalist shoes have been yet little studied. The purpose of this study is to find whether the shoe drop has the same effect regardless of the task: overground or treadmill running. Twelve healthy male subjects ran with three shoes of different drops (0, 4, 8 mm) and barefoot on a treadmill and overground. Vertical ground reaction force (vGRF) (transient peak and loading rate) and lower limb kinematics (foot, ankle and knee joint flexion angles) were observed. Opposite footwear effects on loading rate between the tasks were observed. Barefoot running induced higher loading rates during overground running than the highest drop condition, while it was the opposite during treadmill running. Ankle plantar flexion and knee flexion angles at touchdown were higher during treadmill than overground running for all conditions, except for barefoot which did not show any difference between the tasks. Shoe drop appears to be a key parameter influencing running pattern, but its effects on vGRF differ depending on the task (treadmill vs. overground running) and must be considered with caution. Unlike shod conditions, kinematics of barefoot condition was not altered by treadmill running explaining opposite conclusions between the tasks.

The Effect of Ankle Taping to Restrict Plantar Flexion on Ball and Foot Velocity During an Instep Kick in Soccer.

Posterior ankle impingement syndrome is a common disorder in soccer players and ballet dancers. In soccer players, it is caused by the repetitive stress of ankle plantar flexion due to instep kicking. Protective ankle dorsiflexion taping is recommended with the belief that it prevents posterior ankle impingement. However, the relationship between ankle taping and ball-kicking performance remains unclear. To demonstrate the relationship between the restrictions of ankle taping and performance of an instep kick in soccer. Laboratory-based repeated-measures. University laboratory. 11 male university soccer players. The subjects' ankle plantar flexion was limited by taping. Four angles of planter flexion (0°, 15°, 30°, and without taping) were formed by gradation limitation. The subjects performed maximal instep kicks at each angle. The movements of the kicking legs and the ball were captured using 3 high-speed cameras at 200 Hz. The direct linear-transformation method was used to obtain 3-dimensional coordinates using a digitizing system. Passive ankle plantar-flexion angle, maximal plantar-flexion angle at ball impact, ball velocity, and foot velocity were measured. The data were compared among 4 conditions using repeated-measures ANOVA, and the correlations between ball velocity and foot velocity and between ball velocity and toe velocity were calculated. Ankle dorsiflexion taping could gradually limit both passive plantar flexion and plantar flexion at the impact. Furthermore, limitation of 0° and 15° reduced the ball velocity generated by instep kicks. Plantar-flexion-limiting taping at 30° has a potential to prevent posterior ankle impingement without decreasing the ball velocity generated by soccer instep kicks.

A comparison of dorsal and heel plate foot tracking methods on lower extremity dynamics

The primary method to model ankle motion during inverse dynamic calculations of the lower limb is through the use of skin-mounted markers, with the foot modeled as a rigid segment. Motion of the foot is often tracked via the use of a marker cluster triad on either the dorsum, or heel, of the foot/shoe. The purpose of this investigation was to evaluate differences in calculated lower extremity dynamics during the stance phase of gait between these two tracking techniques. In an analysis of 7 subjects, it was found that sagittal ankle angles and sagittal ankle, hip and knee moments were strongly correlated between the two conditions, however, there was a significant difference in peak ankle plantar flexion and dorsiflexion angles. Frontal ankle angles were only moderately correlated and there was a significant difference in peak ankle eversion and inversion, resulting in moderate correlations in frontal plane moments and a significant difference in peak hip adductor moments. We demonstrate that the technique used to track the foot is an important consideration in interpreting lower extremity dynamics for clinical and research purposes.

Functional electrical stimulation to ankle dorsiflexor and plantarflexor using single foot switch in patients with hemiplegia from hemorrhagic stroke.

ObjectiveTo evaluate the effects of functional electrical stimulation (FES) to ankle dorsiflexor (DF) and ankle plantarflexor (PF) on kinematic and kinetic parameters of hemiplegic gait.MethodsFourteen post-stroke hemiplegic patients were considered in this study. Electrical stimulation was delivered to ankle DF during the swing phase and ankle PF during the stance phase via single foot switch. Kinematic and kinetic data were collected using a computerized motion analysis system with force plate. Data of no stimulation (NS), DF stimulation only (DS), DF and PF stimulation (DPS) group were compared among each other.ResultsPeak ankle dorsiflexion angle during swing phase is significantly greater in DS group (-1.55°±9.10°) and DPS group (-2.23°±9.64°), compared with NS group (-6.71°±11.73°) (p<0.05), although there was no statistically significant difference between DS and DPS groups. Ankle plantarflexion angle at toe-off did not show significant differences among NS, DS, and DPS groups. Peak knee flexion in DPS group (34.12°±13.77°) during swing phase was significantly greater than that of NS group (30.78°±13.64°), or DS group (32.83°±13.07°) (p<0.05).ConclusionIn addition to the usual FES application stimulating ankle DF during the swing phase, stimulation of ankle PF during stance phase can help to increase peak knee flexion during the swing phase. This study shows the advantages of stimulating the ankle DF and PF using single foot switch for post-stroke gait.