Differences in the coordination and its variability among foot joints during running in neutral foot and flatfoot

Comparison of shank, rearfoot and forefoot coordination and its variability between runners with different strike patterns

This study aims to compare shank, rearfoot and forefoot coordination and its variability between runners with habitual rearfoot strike (RFS) and non-RFS (NRFS). 58 healthy males participated in this study (32 RFS, 26 NRFS). Coordination patterns and variability were assessed for the shank, rearfoot, and forefoot segments using a modified vector coding technique during running. RFS runners exhibited significantly greater proportion of anti-phase with distal dominancy (rearfoot) during early and mid-stance, as well as a lower proportion of anti-phase with proximal dominancy (shank) during early stance compared to NRFS runners in frontal rearfoot - transverse shank (FRTS). Conversely, NRFS runners demonstrated significantly greater proportion of anti-phase with distal dominance (forefoot) in the sagittal, frontal, and transverse planes during early stance compared to RFS runners. Coordination variabilities for the FRTS (late stance), frontal rearfoot - frontal forefoot (FRFF) (early and late stance), and frontal rearfoot - transverse forefoot (FRTF) (mid stance) were greater in NRFS than in RFS runners. In contrast, coordination variability for frontal rearfoot - sagittal forefoot (FRSF) (early stance) was greater in RFS than in NRFS runners. The results could further extend the relationship between foot strike pattern and injuries from the perspective of coordination and its variability. Preliminary findings suggest that NRFS runners could benefit from intrinsic foot muscle training to mitigate the sustained loads on the soft tissues of the foot.

Lower limb gait joint coordination variability in people with diabetes-related foot ulcers

BACKGROUND

Diabetes-related foot ulcers pose substantial health risks globally, yet the biomechanical intricacies underlying their development remain incompletely understood. This study aimed to evaluate lower limb gait joint coordination variability in individuals with diabetes-related foot ulcers compared to those with diabetes (without diabetes-related foot ulcers) and healthy controls.

METHODS

A total of 99 participants (diabetes-related foot ulcers cases - 16, Diabetes controls - 50, Health controls - 33) compared three self-paced walking trials. Vector coding, a technique quantifying movement coordination, was employed, analysing hip-knee, knee-ankle, and hip-angle joint couplings in the sagittal plane.

FINDINGS

No significant differences in coordination variability were found among the groups. However, distinct coupling pattern frequencies emerged, with diabetes-related foot ulcers cases exhibiting unique anti-phase hip and ankle coupling frequency counts compared to healthy controls.

INTERPRETATION

These findings challenge conventional understandings of diabetes-related foot ulcers biomechanics and underscore the complexity of gait in this population.

Kinematic coordination in the rearfoot, midfoot, and forefoot differs depending on subgroups based on foot stiffness and kinetic parameters during walking

This study aimed to classify subgroups of healthy young adults based on foot stiffness and related kinetic parameters during gait, as well as to analyze intra-foot sagittal kinematics within each subgroup. Data were collected from 25 males and 24 females using a 3D motion capture system, which measured the rearfoot, midfoot, and forefoot segments. Cluster analysis identified three subgroups based on the following variables: the truss coefficient, windlass coefficient, forward component of ground reaction force (F-GRF), and ankle plantar flexion power. Group 1 demonstrated the highest foot stiffness, as indicated by the largest truss coefficient, while Groups 2 and 3 exhibited lower stiffness, characterized by greater dorsiflexion of the midfoot and forefoot relative to the rearfoot during the stance phase. Additionally, the kinematic coordination patterns between the rearfoot-midfoot and midfoot-forefoot of Groups 2 and 3 during the early and late stance phases showed significant variation. Group 3, in particular, exhibited lower F-GRF and ankle plantar flexion power than Groups 1 and 2. These results suggest that midfoot movement during the late stance phase is critical in generating foot stiffness, with a midfoot-dominant kinematic pattern potentially serving as a key contributor. The study underscores the importance of understanding intersegmental coordination for managing foot stiffness, which could have implications for improving gait mechanics and preventing injuries. Further research is needed to explore how these findings can be applied to individuals with various foot conditions or pathologies.

Differences in Lower-Extremity Joint Coordination During Two Landing Phases of a Drop Jump Task

The aim of the present study was to compare the differences in joint coordination patterns and variability in the lower extremity between the first and second landing phases of the drop jump. Eighteen resistance-trained men (age: 22.8 ± 1.8 years) performed drop jumps from a height of 0.40 m. An eight-camera motion capture system was utilized to record kinematic trajectories. Modified vector coding technique and circular statistics were used to determine the coordination pattern and variability of the following joint couples during the first and second landings: hip frontal-knee frontal (HfKf), hip sagittal-knee frontal (HsKf), hip sagittal-knee sagittal (HsKs), knee frontal-ankle frontal (KfAf), knee sagittal-ankle frontal (KsAf), and knee sagittal-ankle sagittal (KsAs). Statistical differences in the distribution frequencies of coupling angles and variability between the dominant and nondominant limbs across the two landing phases were compared using two-way repeated analysis of variance and Wilcoxon rank-sum tests. During the second landing phase, the proportion of HsKs, KfAf, and KsAs showing in-phase coordination was reduced but the proportion of KfAf and KsAs showing proximal joint (knee) coordination was increased (p < .05). Significant differences in bilateral asymmetry were observed only for the HfKf and KfAf patients (p < .05). HsKs, KfAf, and KsAf varied considerably during the second landing phase (p < .05). Joint coordination patterns during the second landing phase of the drop jump differed considerably from those during the first landing phase, thereby increasing the risk of knee and ankle injuries.

Effects of short foot training on foot posture in patients with flatfeet: A systematic review and meta-analysis

BACKGROUND

With lifestyle changes, the prevalence of flatfoot is increasing year by year, with a prevalence of 29%. Flatfoot will lead to an inevitable injury and reduce the quality of life. Short foot exercises can enhance the strength of the intrinsic muscles of the foot and improve the symptoms of flatfoot. However, there is controversy regarding its specific efficacy.

OBJECTIVE

This meta-analysis quantitatively evaluates the effect of short foot training on patients with flatfeet and provides evidence to inform the clinical approach to short foot training in patients with flat feet.

METHODS

A total of eight databases were searched, including CNKI, WANFANG, VIP, and CBM in Chinese and PubMed, Cochrane, Web of Science, and Embase in English. The timeframe for searching the literature was March 2023 for each database build. English database search terms and search formulas were: (flat foot OR talipes valgus OR talipes calcaneovalgus) AND (short foot exercises OR physical therapy OR neurophysiotherapy).

RESULTS

The current pooled results show no significant difference in the improvement of the navicular drop test and foot posture index with short foot exercises compared to controls; only short foot exercises greater than 6 w showed a significant improvement in the navicular drop test, and sensitivity analysis showed a significant improvement in the foot posture index with short foot exercises.

CONCLUSION

This systematic review and meta-analysis showed that short foot exercises need a larger sample size to find their effect on improving flat feet; the duration of the intervention is a factor. As most studies are currently unclear whether the participants were patients with flat feet or asymptomatic individuals with flat feet the disease syndrome in patients with flatfoot may also be a factor.