High-speed fluoroscopic imaging for investigation of three-dimensional knee kinematics before and after marathon running

The effect of marathon running on the lower extremity kinematics and muscle activities during walking and running tasks

Patellofemoral pain syndrome (PFPS) is a common injury among runners, and it is thought that abnormal lower extremity biomechanics contribute to its development. However, the relationship between biomechanical changes after a marathon and PFPS injury remains limited. This study aims to investigate whether differences in knee and hip kinematics and lower extremity muscle activities exist in recreational runners before and after a marathon. Additionally, it aims to explore the relationship between these biomechanical changes and the development of PFPS injury. 12 recreational runners participated in the study. Kinematics and muscle activities of the lower extremity were recorded during walking (5 km/h) and running (10 km/h) tasks within 24 hours before and within 5 hours after a marathon. After the marathon, there was a significant decrease in peak knee flexion (walking: p = 0.006; running: p = 0.006) and an increase in peak hip internal rotation (walking: p = 0.026; running: p = 0.015) during the stance phase of both walking and running compared to before the marathon. The study demonstrates a decrease in knee flexion and an increase in hip internal rotation during the stance phase of gait tasks after completing a marathon, which may increase the risk of developing PFPS injury.

Acute effect of foot strike patterns on in vivo tibiotalar and subtalar joint kinematics during barefoot running

BACKGROUND

Foot kinematics, such as excessive eversion and malalignment of the hindfoot, are believed to be associated with running-related injuries. The majority of studies to date show that different foot strike patterns influence these specific foot and ankle kinematics. However, technical deficiencies in traditional motion capture approaches limit knowledge of in vivo joint kinematics with respect to rearfoot and forefoot strike patterns (RFS and FFS, respectively). This study uses a high-speed dual fluoroscopic imaging system (DFIS) to determine the effects of different foot strike patterns on 3D in vivo tibiotalar and subtalar joints kinematics.

METHODS

Fifteen healthy male recreational runners underwent foot computed tomography scanning for the construction of 3-dimensional models. A high-speed DFIS (100 Hz) was used to collect 6 degrees of freedom kinematics for participants' tibiotalar and subtalar joints when they adopted RFS and FFS in barefoot condition.

RESULTS

Compared with RFS, FFS exhibited greater internal rotation at 0%-20% of the stance phase in the tibiotalar joint. The peak internal rotation angle of the tibiotalar joint under FFS was greater than under RFS (p < 0.001, Cohen's d = 0.92). RFS showed more dorsiflexion at 0%-20% of the stance phase in the tibiotalar joint than FFS. RFS also presented a larger anterior translation (p < 0.001, Cohen's d = 1.28) in the subtalar joint at initial contact than FFS.

CONCLUSION

Running with acute barefoot FFS increases the internal rotation of the tibiotalar joint in the early stance. The use of high-speed DFIS to quantify the movement of the tibiotalar and subtalar joint was critical to revealing the effects of RFS and FFS during running.

Effects of soft tissue artifacts on the calculated kinematics of the knee during walking and running

Kinematics of the knee during gait has mostly been studied using optical motion capture systems (MCS). The presence of soft tissue artifacts (STA) between the skin markers and the underlying bone presents a major impediment to obtaining a reliable joint kinematics assessment. In this study, we determined the effects of STA on the calculation of knee joint kinematics during walking and running, through the combination of high-speed dual fluoroscopic imaging system (DFIS) and magnetic resonance imaging technique. Ten adults walked and ran while data was collected simultaneously from MCS and high-speed DFIS. The study showed that measured STA underestimated knee flexion angle, but overestimated knee external and varus rotation. The absolute error values of the skin markers derived from knee flexion-extension angle, internal-external rotation, and varus-valgus rotation during walking were -3.2 ± 4.3 deg, 4.6 ± 3.1 deg, and 4.5 ± 3.2 deg respectively, and during running were -5.8 ± 5.4 deg, 6.6 ± 3.7 deg, and 4.8 ± 2.5 deg respectively. Average errors relative to the DFIS for flexion-extension angle, internal-external rotation, and varus-valgus rotation were 78 %, 271 %, 265 % during walking respectively, and were 43 %, 106 %, 200 % during running respectively. This study offers reference for the kinematic differences between MCS and high-speed DFIS, and will contribute to optimizing methods for analyzing knee kinematics during walking and running.

Comparison of instantaneous knee kinematics during walking and running

BACKGROUND

Accurate measurements of in-vivo knee joint kinematics are essential to elucidate healthy knee motion and the changes that accompany injury and repair. Although numerous experimental measurements have been reported, the accurate non-invasive analysis of in-vivo knee kinematics remains a challenge in biomechanics.

RESEARCH QUESTION

The study objective was to investigate in-vivo knee kinematics before, at, and after contact during walking and running using a combined high-speed dual fluoroscopic imaging system (DFIS) and magnetic resonance (MR) imaging technique.

METHODS

Three-dimensional (3D) knee models of ten participants were created using MR images. Knee kinematics during walking and running were determined using high-speed DFIS. The 3D knee models were then related to fluoroscopic images to obtain in-vivo six-degrees-of-freedom knee kinematics.

RESULTS

Before contact knee flexion, external femoral rotation, and proximal-distal distance were 11.9°, 3.4°, and 1.0 mm greater during running compared to walking, respectively. Similar differences were observed at initial contact (9.9°, 7.9°, and 0.9 mm, respectively) and after contact (6.4°, 2.2°, and 0.8 mm, respectively). Posterior femoral translation at initial contact was also increased during running compared to walking.

SIGNIFICANCE

This study demonstrated accurate instantaneous in-vivo knee kinematic characteristics that may further the understanding of the intrinsic biomechanics of the knee during gait.