Investigating the Effect of Real-Time Center of Pressure (CoP) Feedback Training on the Swing Phase of Lower Limb Kinematics in Transfemoral Prostheses with SACH foot

Transfemoral amputee often encounters reduced toe clearance resulting in trip-related falls. Swing phase joint angles have been shown to influence the toe clearance therefore, training intervention that targets shaping the swing phase joint angles can potentially enhance toe clearance. The focus of this study was to investigate the effect of the shift in the location of the center of pressure (CoP) during heel strike on modulation of the swing phase joint angles in able-bodied participants (n=6) and transfemoral amputees (n=3). We first developed a real-time CoP-based visual feedback system such that participants could shift the CoP during treadmill walking. Next, the kinematic data were collected during two different walking sessions- baseline (without feedback) and feedback (shifting the CoP anteriorly/posteriorly at heel strike to match the target CoP location). Primary swing phase joint angle adaptations were observed with feedback such that during the mid-swing phase, posterior CoP shift feedback significantly increases (p<0.05) the average hip and knee flexion angle by 11.55 degrees and 11.86 degrees respectively in amputees, whereas a significant increase (p<0.05) in ankle dorsiflexion, hip and knee flexion angle by 3.60 degrees, 3.22 degrees, and 1.27 degrees respectively compared to baseline was observed in able-bodied participants. Moreover, an opposite kinematic adaptation was seen during anterior CoP shift feedback. Overall, results confirm a direct correlation between the CoP shift and the modulation in the swing phase lower limb joint angles.

Influence of the Amount of Change in Quadriceps Tendon Young’s Modulus on Amount of Change in Walking Speed before and after Total Knee Arthroplasty

Background and Objectives: Walking speed after total knee arthroplasty (TKA) is an important outcome. However, the effect of quadriceps tendon stiffness on walking speed remains unclear. This study aimed to clarify the influence of the amount of change in quadriceps tendon stiffness on the degree of change in walking speed before and after TKA. Materials and Methods: Sixteen patients who underwent TKA for knee osteoarthritis participated in this study (median age: 74.0 years (interquartile range: 64.5–75.8)). Shear-wave elastography was deployed to measure quadriceps tendon stiffness using Young’s modulus. A motion analysis system was used to assess kinematic parameters and walking speed. Participants’ knee circumference, range of motion, extension strength, one-leg standing time, walking pain level, and activity level were measured preoperatively and one year after TKA, and changes in values were calculated. We used path analysis to clarify the influence of the amount of change in the quadriceps tendon Young’s modulus on the change in walking speed. Results: The quadriceps tendon Young’s modulus negatively affected the knee flexion angle during swing (standardized partial regression coefficients (β) = −0.513, p = 0.042). The knee flexion angle during swing positively affected step length (β = 0.586, p = 0.017). Step length positively affected cadence (β = 0.733, p = 0.001). Step length and cadence positively affected walking speed (β = 0.563, p < 0.001, β = 0.502, p < 0.001, respectively). Conclusions: The amount of change in the quadriceps tendon Young’s modulus may affect the degree of change in walking speed after TKA through the amount of change in the knee flexion angle during swing, step length, and cadence. Clinically, reducing quadriceps tendon stiffness can be addressed in rehabilitation programs to increase walking speed after TKA.

The Relationship between Leg Extension Angle at Late Stance and Knee Flexion Angle at Swing Phase during Gait in Community-Dwelling Older Adults

This study aimed to clarify the relationship between leg extension angle and knee flexion angle during gait in older adults. The subjects of this cross-sectional study were 588 community-dwelling older adults (74.6 ± 6.1 y). Segment angles and acceleration were measured using five inertial measurement units during comfortable gait, and bilateral knee and hip joint angles, and leg extension angle, reflecting whole lower limb extension at late stance, were calculated. Propulsion force was estimated using the increase in velocity calculated from anterior acceleration of the sacrum during late stance. Correlation analysis showed that leg extension angle was associated with knee flexion angle at swing phase and hip extension angle and increase in velocity at late stance (r = 0.444–508, p < 0.001). Multiple regression analysis showed that knee flexion angle at mid-swing was more affected by leg extension angle (β = 0.296, p < 0.001) than by gait speed (β = 0.219, p < 0.001) and maximum hip extension angle (β = −0.150, p < 0.001). These findings indicate that leg extension angle may be a meaningful parameter for improving gait function in older adults due to the association with knee kinematics during swing as well as propulsion force at late stance.

Effect of Leg Extension Angle on Knee Flexion Angle during Swing Phase in Post-Stroke Gait

Background and Objectives: Leg extension angle is important for increasing the propulsion force during gait and is a meaningful indicator for evaluating gait quality in stroke patients. Although leg extension angle during late stance might potentially also affect lower limb kinematics during the swing phase, the relationship between these two remains unclear. This study aimed to investigate the relationship between leg extension angle and knee flexion angle during pre-swing and swing phase in post-stroke gait. Materials and Methods: Twenty-nine stroke patients walked along a 16 m walkway at a self-selected speed. Tilt angles and acceleration of pelvis and paretic lower limb segments were measured using inertial measurement units. Leg extension angle, consisting of a line connecting the hip joint with the ankle joint, hip and knee angles, and increments of velocity during pre-swing and swing phase were calculated. Correlation analysis was conducted to examine the relationships between these parameters. Partial correlation analysis adjusted by the Fugl-Meyer assessment-lower limb (FMA-LL) was also performed. Results: On the paretic side, leg extension angle was positively correlated with knee flexion angle during the swing phase (r = 0.721, p < 0.001) and knee flexion angle and increments of velocity during the pre-swing phase (r = 0.740–0.846, p < 0.001). Partial correlation analysis adjusted by the FMA-LL showed significant correlation between leg extension angle and knee flexion angle during the swing phase (r = 0.602, p = 0.001) and knee flexion angle and increments of velocity during the pre-swing phase (r = 0.655–0.886, p < 0.001). Conclusions: Leg extension angle affected kinematics during the swing phase in post-stroke gait regardless of the severity of paralysis, and was similar during the pre-swing phase. These results would guide the development of effective gait training programs that enable a safe and efficient gait for stroke patients.

Drop Landing Biomechanics in Individuals With and Without a Concussion History

Research has identified an increased risk of lower extremity injury postconcussion, which may be due to aberrant biomechanics during dynamic tasks. The purpose of this study was to compare the drop landing biomechanics between individuals with and without a concussion history. Twenty-five individuals with and 25 without a concussion history were matched on age (±3 y), sex, and body mass index (±1 kg/m2). Three-dimensional landing biomechanics were recorded to obtain dependent variables (peak vertical ground reaction force, loading rate, knee flexion angle and external moment, knee abduction angle and external moment, and knee flexion and abduction angle at ground contact). A 1-way multivariate analysis of variance compared outcomes between groups. There was no difference in drop landing biomechanics between individuals with and without a concussion history (F10,39 = 0.460, P = .877, Wilk Λ = .918). There was an effect of time since concussion on knee flexion characteristics. Time since most recent concussion explained a significant amount of variation in both peak (ΔR2 = .177, β = −0.305, ΔP = .046) and initial ground contact (ΔR2 = .292, β = −0.204, ΔP = .008) knee flexion angle after covarying for sex and body mass index. Therefore, time since concussion should be considered when evaluating biomechanical patterns.

Distal Femoral Extension Osteotomy and Patellar Tendon Advancement in Management of Fixed Knee Flexion Deformity and Crouch Gait in Cerebral Palsy

Background Cerebral palsy (CP) is generally associated with musculoskeletal deformities that occur during body growth. Fixed knee flexion deformity (FKFD) results from long standing knee flexion that is due to progressive contracture of spastic hamstrings combined with a quadriceps weakness. Fixed knee flexion compromises the passive mechanisms of joint stabilization at mid and terminal stance in children with CP. The aim of this study is to highlight the results of distal femoral extension osteotomy and patellar tendon advancement (DFEO + PTA) for management of FKFD in crouching CP patients with spastic or mixed tone diplegic ambulatory cerebral palsy children. Patients and Methods A prospective study was conducted involving twenty CP patients with fixed knee flexion deformity (14 males and 6 females). The 20 cases with fixed knee flexion deformity were GMFCS level II (4 cases), and III (16 cases). All patients were clinically and radiologically assessed according to knee flexion angle, extension lag, koshino index and the Gross motor function measure pre- and post-operative. All patients underwent DFEO ± PTA. Eighteen limbs had DFEO on the RT side, and twenty on the LT side. Results The mean age of the patients was 11.18±3.23 (6-16) years. The period of follow up ranged from 12 to 24 months (The mean follow up was 16.20 ± 2.46). At last follow up, the median knee flexion angle improved from 25 to 0. The median extension lag improved from 17.5 to 0. The mean koshino index improved from 1.59 ± 0.32 to 1.05 ± 0.10. the GMFM improved from 52.86 ± 7.36 to 68.15 ± 5. 82. Conclusion The combined procedure (DFEO + PTA) is effective in increasing knee extension in the stance phase, reducing knee pain and improving knee extension strength.

Effect of Femoral Nerve Block with Different Concentrations of Chloroprocaine on the Recovery of Joint Function in Rehabilitation Training after Knee Replacement: A Prospective, Double-Blind, Randomized, Controlled Clinical Study

Background: Patients who undergo total knee arthroplasty (TKA) experience severe pain after surgery. Especially active pain in early postoperative rehabilitation training of the knee joint is particularly severe, and it should receive people’s attention.Methods: A total of 90 patients who only received unilateral TKA in our hospital were randomly and equally divided into three groups (group C1: 1% chloroprocaine, group C2: 2% chloroprocaine, and group NS: 0.9% sodium chloride solution 0.2 ml/kg; the dosage was fixed at 0.2 ml/kg for all three groups). All patients received femoral nerve catheterization before TKA and started rehabilitation training 48 h after TKA. The visual analogue scale (VAS) scores of active exercises before and after administration were observed and recorded. VAS scores, maximum knee flexion and extension angles, the incidence of knee flexion angle ≥100° in each group, the American knee society(AKS) scores, together with postoperative rehabilitation training satisfaction and adverse effects were recorded at 7 days and 3 months after surgery.Results: Compared with the NS group, VAS scores after administration of patients in the group C1 and C2 were decreased significantly at each time point (P < 0.05), and the maximum knee flexion angles were increased significantly (P < 0.05), as well as the proportion of maximum knee angle ≥100° (P < 0.05). The postoperative rehabilitation training satisfaction of patients in group C1 and C2 were more than that of patients in the NS group (P < 0.05).Conclusion: The administration of 1% chloroprocaine for femoral nerve block before rehabilitation training after TKA could improve the knee flexion angle at the early postoperative stage, increase the proportion of patients who could squat, and cause fewer side effects.

Effects of Video Task With a High-Level Exercise Illustration on Knee Movements in Male Volleyball Spike Jump

Hazardous knee biomechanics, such as excessive knee affordance link with injuries in volleyball spike jumps (SPJs) and can be reconfigured by the enhancement of internal focus. The study aimed to explore the effects of video tasks illustrating a high-level SPJ on knee movement in the volleyball SPJ with 15 elite male volleyball athletes. This study investigated the knee movements in sagittal, coronal, and transverse planes before and after the video task in SPJ using one-dimensional statistical parametric mapping (SPM 1D) and discrete statistics. The SPM 1D indicated a larger knee flexion angle (31.17–73.19%, t = 2.611, and p = 0.012), increased knee flexion moment (19.72–21.38%, t = 0.029, and p = 0.029), and increased knee adduction angular velocity (49.07–62.64%, t = 3.148, and p = 0.004) after video task; alternatively, smaller knee external rotation angular velocity (45.85–49.96%, t = 5.199, and p = 0.017) and vertical ground reaction (vGRF) (3.13–5.94%, t = 4.096, and p = 0.014; 19.83–21.97%, t = 4.096, and p = 0.024) were found after the task. With discrete value statistics, the video task increased the peak of knee flexion angle while decreased the peak of extension moment, flexion moment, abduction moment, external moment, the first peak vGRF, and related loading rate.Conclusions: The results indicate that knee biomechanics in volleyball SPJ positively influenced by the video task. The task has the athletes control the knee movements more actively and improves the original hazardous movement strategies. Therefore, the video task presumably can abate the occurrence of knee injuries in volleyball SPJ. Further validation especially in the exercise effect is needed in the future.

Effect of aqua walking exercise on knee joint angles, muscular strength, and visual analogue scale for patients with limited range of motion of the knee

The purpose of this study is to identify the effects of aqua walking exercise on the joint range of motion (ROM), muscular strength, and pain in patients who have limited knee ROM from surgery or joint fixation. Ten subjects were participated in this study and divided into two groups: continuous passive motion (CPM) therapy+walking exercise on dryland (CWD) and CPM+aqua walking exercise (CAW) groups. The repeated measures analysis of variance was used to verify the difference between the groups and the duration of the program. A paired t-test was used to verify the significance of the observed difference within the groups, and an independent t-test was used to verify the significance of the observed difference between different groups. In this study, ROM in the knee flexion showed interaction effect between the two groups. CAW had a significant increase of knee flexion angle compared to those in CWD. Also, strength on the knee flexors showed interaction effect between the two groups. CAW had a significant increase of knee flexion angle compared to those in CWD, while strength on the knee extensors showed no significant interaction effect between groups. Visual analogue scale (VAS) score showed interaction between the two groups. CAW had a significant increase of the VAS scores compared to those in CWD. Given these findings reported in present study, aqua walking exercise for patients with osteoarthritis is a very safe and effective therapeutic strategies that can move the joint in the optimal ROM.