Midfoot and Ankle Mechanics in Block and Incline Heel Raise Exercises

Fatigue of the intrinsic foot core muscles had a greater effect on gait than extrinsic foot core muscles: A time-series based analyze

BACKGROUND

The Heel Rise endurance (HRE) which indicates the extrinsic foot core (ECO) muscle's performance and the paper grip endurance (PGE) which indicates the intrinsic foot core (ICO) muscle's performance are essential components of a healthy foot function. However, the foot core muscles' fatigue response on spatial and temporal gait parameters after the HRE and the PGE tests were not adequately investigated. The purpose of this study was to determine whether the fatigue of the ICO and the ECO muscles affect gait parameters.

MATERIAL AND METHODS

A prospective, cross-sectional study was conducted on 22 sedentary individuals (44 feet). Gait was investigated pre and after the Heel Rise (HR) endurance test and the paper grip (PG) endurance test by inertial sensors. At least 500 consecutive steps were collected for each individual. Spatial-temporal gait parameters were used as outcome measures.

RESULTS

ECO fatigue and ICO fatigue led to increases in the step length (p < 0.05) and the stride lengths (p < 0.05), the single support (p < 0.05), and the terminal stance durations (p < 0.05). It was also seen that ICO fatigue had a greater effect on gait than ECO fatigue. The ECO fatigue had a medium to large effect on the gait parameters (d=0.313-0.646). The ICO fatigue affected gait with a large effect (d=0.524-2.048).

CONCLUSION

The ECO fatigue and the ICO fatigue led to clinically important changes in long-range gait parameters and the ICO fatigue had a greater effect on gait than ECO fatigue. It was suggested that clinicians add ICO muscle endurance training to improve the physical performance of individuals.

"Knees Out" or "Knees In"? Volitional Lateral vs. Medial Hip Rotation During Barbell Squats

ABSTRACT

Chiu, LZF. "Knees out" or "Knees in"? Volitional lateral versus medial hip rotation during barbell squats. J Strength Cond Res 38(3): 435-443, 2024-Medial or lateral hip rotation may be present during barbell squats, which could affect the hip frontal and transverse plane moments. Male (n = 14) and female (n = 18) subjects performed squats using their normal technique and with volitional medial and lateral hip rotation. Hip net joint moments (NJM) were calculated from 3-dimensional motion capture and force platform measurements. Statistical significance was set for omnibus tests (α = 0.05) and Bonferroni's corrected for pairwise comparisons (αt-test = 0.0056). Normal squats required hip extensor, adductor, and lateral rotator NJM. Lateral rotation squats had smaller hip extensor (p = 0.002) and lateral rotator (p < 0.001) NJM and larger hip adductor (p < 0.001) NJM than normal squats. Medial rotation squats had smaller hip extensor (p = 0.002) and adductor (p < 0.001) NJM and larger hip lateral rotator (p < 0.001) NJM than normal squats. These differences exceeded the minimum effects worth detecting. As gluteus maximus exerts hip extensor and lateral rotator moments, and the adductor magnus exerts hip extensor and adductor moments, these muscles combined would be required to meet these hip demands, supporting previous research that has established these muscles as the primary contributors to the hip extensor NJM. Lateral rotation squats reduce hip lateral rotator and increase hip adductor NJM, which may be hypothesized as preferentially loading adductor magnus. Medial rotation squats increase hip lateral rotator and decrease hip adductor NJM; therefore, this variant may shift loading to the gluteus maximus.

Association of Fusion of the First Metatarsophalangeal Joint and Pes Planus Deformity Correction

BACKGROUND

There has been scant investigation on the relationship between the distal aspect of the medial longitudinal arch and pes planus deformity. The aim of this study was to investigate whether the reduction and stabilization of the distal aspect of the medial longitudinal arch through fusion of the first metatarsophalangeal joint (MTPJ) can subsequently improve pes planus deformity parameters. This could be useful in both further understanding the role of the distal medial longitudinal arch in patients with pes planus and planning operative intervention in patients with multifactorial medial longitudinal arch problems.

METHODS

A retrospective cohort study was undertaken between January 2011 and October 2021, including patients undergoing first MTPJ fusion with a pes planus deformity on weightbearing preoperative radiographs. These were compared to postoperative images, and multiple pes planus measurements were taken for comparison.

RESULTS

A total of 511 operations were identified for further analysis, with 48 feet meeting the inclusion criteria. There was a statistically significant reduction identified between the pre- and postoperative measurements of Meary angle (3.75 degrees, 95% CI 2.9-6.47 degrees) and talonavicular coverage angle (1.48 degrees, 95% CI 1.09-3.44 degrees). There was a statistically significant increase between the pre- and postoperative measurements of calcaneal pitch angle (2.32 degrees, 95% CI 0.24-4.41 degrees) and medial cuneiform height (1.25 mm, 95% CI 0.6-1.92 mm). Reduced intermetatarsal angle was significantly associated with an increase in first MTPJ angle postfusion. Many of the measurements made were found "almost perfectly" reproducible by the Landis and Koch description.

CONCLUSION

Our results demonstrate that fusion of the first MTPJ is associated with improvement of medial longitudinal arch parameters of a pes planus deformity but not to levels considered to be clinically normal. Therefore, the distal aspect of the medial longitudinal arch could, to some degree, be a feature in the pes planus deformity etiology.

LEVEL OF EVIDENCE

Level III, retrospective case control study.

Effect of incline versus block heel-raise exercise on foot muscle strength and vertical jump performance - an 11-week randomized resistance training study

Strengthening the toe flexors and ankle plantar flexors may improve vertical jump performance. One exercise that may be effective for concurrently strengthening these muscles is heel-raises performed on an incline. The purpose of this study was to investigate the effects of incline versus conventional (block) heel-raise exercise on hallux and II-V digit flexor strength, vertical jump performance, and ankle plantar flexor strength. Thirty-three female volleyball players were randomly allocated to perform incline (n = 17) or block (n = 16) heel-raise exercise for 11-weeks. Participants' toe flexor strength, countermovement jump, approach jump, and ankle plantar flexor strength were assessed before, after 7 weeks, and after 11 weeks of exercise. There were no significant time-by-group interactions for any variable (p > 0.05). However, both groups improved their hallux flexor strength (Δ0.27 ± 0.50 N·kg-1; p < 0.05), and vertical countermovement (Δ1.2 ± 2.3 cm; p < 0.05) and approach (Δ1.9 ± 2.6 cm; p < 0.05) jump height from pre- to post-test. No changes were observed in the ankle plantar flexor or II-V digit flexor strength (n > 0.05). Both incline and conventional heel-raises improve toe flexor strength. Practitioners seeking to improve individuals' foot function may consider incorporating incline or block heel-raises.