Modulations of Foot and Ankle Frontal Kinematics for Breaking and Propulsive Movement Characteristics during Side-Step Cutting with Varying Midsole Thicknesses

Effects of midsole thickness on ground reaction force, ankle stability, and sports performances in four basketball movements

Changes in midsole thickness can influence cushioning and rearfoot stability in running, but no information has been established in basketball. This study aimed to investigate whether midsole thickness would alter ground reaction force, ankle stability and performance-related indicators in four basketball manoeuvres. Fifteen university basketball athletes performed lateral shuffle, forward sprint, counter-movement jump (CMJ) and drop landing in basketball shoes of five midsole thicknesses (Thinnest, Thin, Medium, Thick, Thickest). One-way repeated-measures ANOVA was performed on each of the biomechanics and performances variables and Friedman test was performed on comfort perceptions. Our findings found a significant midsole thickness effect on the lower extremity biomechanics (p < 0.05), with better traction (p = 0.019) and greater plantarflexion (p = 0.019) while sprinting with thinner shoe conditions. Thicker basketball shoes led to greater rearfoot inversion (p = 0.004) and a more significant inversion velocity peak (p = 0.019) during lateral shuffling. No significant difference in peak impact force or peak loading rate was observed between shoes during drop landing. These findings suggest that participants wearing basketball shoes with thicker midsole may lead to ankle instability during lateral shuffling manoeuvres. Wearing basketball shoes with thinner midsoles may be beneficial for sprint and jump performances.

Changes in the Kinematics of Midfoot and Rearfoot Joints with the Use of Lateral Wedge Insoles

The lateral wedge insole (LWI) is a typical orthopedic treatment for medial knee osteoarthritis pain, chronic ankle instability, and peroneal tendon disorders. It is still unknown what the effects are in the most important joints of the foot when using LWIs as a treatment for knee and ankle pathologies. Objectives: The aim of this study was to determine the influence of LWIs on the position of the midfoot and rearfoot joints by measuring the changes using a tracking device. Methods: The study was carried out with a total of 69 subjects. Movement measurements for the midfoot were made on the navicular bone, and for the rearfoot on the calcaneus bone. The Polhemus system was used, with two motion sensors fixed to each bone. Subjects were compared by having them use LWIs versus being barefoot. Results: There were statistically significant differences in the varus movement when wearing a 4 mm LWI (1.23 ± 2.08°, p < 0.001) versus the barefoot condition (0.35 ± 0.95°), and in the plantarflexion movement when wearing a 4 mm LWI (3.02 ± 4.58°, p < 0.001) versus the barefoot condition (0.68 ± 1.34°), in the midfoot. There were also statistically significant differences in the valgus movement when wearing a 7 mm LWI (1.74 ± 2.61°, p < 0.001) versus the barefoot condition (0.40 ± 0.90°), and in the plantar flexion movement when wearing a 4 mm LWI (2.88 ± 4.31°, p < 0.001) versus the barefoot condition (0.35 ± 0.90°), in the rearfoot. Conclusions: In the navicular bone, a varus, an abduction, and plantar flexion movements were generated. In the calcaneus, a valgus, an adduction, and plantar flexion movements were generated with the use of LWIs.

Do harder midsoles facilitate propulsion and do softer midsoles increase shock attenuation during taking-off and landing of scissor jump?

To determine the influence of midsole hardness on ground reaction force (GRF) features during badminton scissor jump takeoff and landing and the interactive effect of midsole hardness with playing and nonplaying limbs, data were collected from badminton athletes who performed scissor jumps while wearing shoes with two levels of midsole hardness. Temporal-spatial and GRF variables were calculated. Measurements of the soft and hard midsole conditions for playing versus non-playing sides were compared using two-way repeated measure analyses of variance. The playing and non-playing limbs showed different GRF features while performing scissor jump. During takeoff, no significant differences between the soft and hard midsole conditions were identified for the jump height in any of the GRF variables. During landing, the cushioning capacity might be affected by harder midsole indicated by higher vertical impact peak (p = 0.008). Meanwhile, the longer time-to-vertical impact peak (p = 0.007) and the lower loading rate of the vertical impact peak (p = 0.013) may be plausible indicators for cushioning. Current study indicated the playing-limb consistently showed dominance on both the propulsion and shock attenuation behaviours during scissor jump and that, for the footwear selection between 62C and 68C midsoles, expectation would be more on effects on landing characteristics than on propulsion performance.

Kinematic Effect on the Navicular Bone with the Use of Rearfoot Varus Wedge

BACKGROUND

The rearfoot varus wedge (RVW) is a common treatment for foot pain and valgus deformity. There is research on its effects in the calcaneus, but there is little research on the navicular. More research is needed with the use of RVW due to the relationship that exists between the position of the navicular and the risk of suffering an injury.

OBJECTIVES

this study sought to understand how RVW can influence the kinematics of the navicular bone, measuring their movement with the 6 SpaceFastrak system.

METHODS

a total of 60 subjects participated in the study. Two sensors were used to measure the movement of the calcaneus and navicular using RVWs as compared in the barefoot position in a static way.

RESULTS

there were statistically significant differences, the use of RVWs caused changes in the navicular bone, with subjects reaching the maximum varus movement with the use of RVW 7 mm of 1.35 ± 2.41° (p < 0.001), the maximum plantar movement flexion with the use of RVW 10 mm of 3.93 ± 4.44° (p < 0.001).

CONCLUSIONS

when RVWs were placed under the calcaneus bone, the navicular bone response was in varus movement too; thus, the use of rearfoot varus wedge can influence the movement of the navicular bone.

Ground Reaction Forces and Temporal Characteristics Define Cutting Performance

Moderate angle cutting maneuvers (between 45º and 90º) are common and essential performance skills for success in multidirectional sports. Research addresses the injury risks of cutting but few studies have attempted to quantify the performance of the cut itself.

PURPOSE

To identify any anthropometric, kinematic, and/or kinetic markers of a high-performance cut so they may be taught and lead to more effective training.

METHODS

Ten college-aged male athletes (mass 73.97 ± 8.77kg, height 1.81 ± 0.07m) and ten non-athletes (mass 87.37 ± 13.93kg, height 1.85 ± 0.04m) completed five moderate angle cutting trials with a speed constraint of 4.03 m/s - 4.44 m/s through a 3 m in to and 3 m out of a 60° change in direction set-up. Kinetic and kinematic measurements were recorded through ground reaction forces and lower limb angles.

RESULTS

A Bonferroni correction revealed that athletes spent significantly less time in the propulsion phase (52.0% ± 0.02%, p < 0.02) compared to non-athletes (55.4% ± 0.03%, p < 0.02). The propulsion phase was determined as the percentage of the contact phase the knee was extending (e.g. Green, et al, 2012). The athletes produced significantly greater instantaneous values of X GRF, Y GRF, and Z GRF during the propulsion phase (p < .05).

CONCLUSION

Greater GRFs coupled with shorter propulsion phases by the athletes accounted for the lack of differences in the propulsion impulse between the two groups. Changing direction in a shorter time improves an athlete's ability to evade an opponent, by decreasing the time an opponent has to react to a new direction.