The effects of hip external rotator exercises and toe-spread exercises on lower extremity muscle activities during stair-walking in subjects with pronated foot

Step width modification to change rearfoot eversion and medial longitudinal arch angle during walking and running in individuals with pronated feet

BACKGROUND

Individuals with pronated feet often experience altered foot biomechanics, leading to increased risk of lower limb injuries. Step width modification has been proposed as a potential intervention to improve foot alignment during gait.

RESEARCH QUESTION

Does modifying step width influence rearfoot eversion and medial longitudinal arch angle (MLAA) in individuals with pronated feet during walking and running?

METHODS

Twenty individuals with pronated feet underwent analysis during walking and running on treadmill, maintaining increased or decreased step width using real-time visual feedback. Three-dimensional motion analysis measured rearfoot eversion and MLAA during the stance phase of gait.

RESULTS

Wide step width significantly reduced peak rearfoot eversion during waking (mean difference - with normal step width - (MD) = 3.6°, p < 0.001) and running (MD = 4.4°, p < 0.001), time to peak rearfoot eversion during walking (MD = 16.6 p < 0.001) and running (MD = 13.8°, p = 0.014), rearfoot eversion at touch down (TD) during walking (MD = 1.3°, p = 0.004), rearfoot eversion excursion during running (MD = 4.3°, p < 0.001), and peak MLAA during walking (MD = 2.9°, p = 0.006) and MLAA excursion during running (MD = 4.8°, p = 0.004). By contrast, during running, narrow condition significantly increased peak rearfoot eversion (MD = 3.4°, p < 0.001). During walking, time to peak rearfoot eversion (MD = 16.1, p < 0.001), rearfoot eversion at TD (MD = 1.4°, p = 0.008), rearfoot eversion excursion (MD = 5.9°, p < 0.001), and peak MLAA (MD = 3.4°, p < 0.001) were significantly increased.

SIGNIFICANCE

This study highlights the potential of step width modification as a simple yet effective intervention to improve foot biomechanics in pronated feet individuals during walking and running. Further research could lead to the development of personalized strategies for pronated feet individuals.

Reductions in rearfoot eversion posture due to proximal muscle strengthening are dependent on foot-ankle varus alignment

BACKGROUND

Strengthening the hip and trunk muscles may decrease foot pronation in upright standing due to expected increases in hip passive torque and lower-limb external rotation. However, considering the increased pronation caused by a more varus foot-ankle alignment, subjects with more varus may experience smaller or no postural changes after strengthening.

OBJECTIVE

To investigate the effects of hip and trunk muscle strengthening on lower-limb posture during upright standing and hip passive torque of women with more and less varus alignment.

METHODS

This nonrandomized controlled experimental study included 50 young, able-bodied women. The intervention group (n = 25) performed hip and trunk muscle strengthening exercises, and the control group (n = 25) maintained their usual activities. Each group was split into two subgroups: those with more and less varus alignment. Hip, shank, and rearfoot-ankle posture and hip passive external rotation torque were evaluated. Mixed analyses of variance and preplanned contrasts were used to assess prepost changes and between-group differences (α = 0.05).

RESULTS

The less-varus subgroup of the intervention group had a reduced rearfoot eversion posture (P = 0.02). No significant changes were observed in the less-varus subgroup of the control group (P = 0.31). There were no significant differences in posture between the control and intervention groups when varus was not considered (P ≥ 0.06). The intervention group had increased hip passive torque (P = 0.001) compared to the control group, independent of varus alignment.

CONCLUSION

Despite the increases in hip passive torque, the rearfoot eversion posture was reduced only in women with a less-varus alignment. Having more foot-ankle varus may prevent eversion reductions.

Effects of physical interventions on pain and disability in chronic low back pain with pronated feet: a systematic review and meta-analysis

BACKGROUND

A link between pronated feet (PF) and chronic low back pain (CLBP) has been reported in the literature. However, physical interventions (PI) like physiotherapy and orthotics mainly target the lower back, neglecting the broader biomechanical impacts of PF that affect the feet, ankles, and overall posture. Currently, there is a lack of comprehensive meta-analyses or systematic reviews on this subject.

OBJECTIVES

This systematic review with a meta-analysis aimed to evaluate the effects of PI on pain and disability in patients having CLBP with PF.

METHODS

From inception until October 15, 2023, Medline/PubMed, Web of Science, and Scopus databases were searched using the desired keywords for randomized control trials (RCTs). The quality of the RCTs was evaluated using the PEDro scale and risk of bias tool.

RESULTS

Four studies involving 268 patients were identified, two compared custom-made foot orthoses to non-biomechanical foot insoles, while the other two used exercises. The meta-analysis included four studies for pain and three for disability. The results showed a significant change in pain [-2.43 (95% CI -2.73 to -2.13, p < .001)] and disability of -6.69 (95% CI -8.04 to -5.33, p < .001)].

CONCLUSIONS

This systematic review and meta-analysis of four RCTs elucidates that PI, specifically targeting PF, significantly alleviate pain and reduce disability in patients having CLBP with PF. These findings advocate for integrating foot-based PI within the treatment protocols for patients suffering from CLBP accompanied by PF.

Using a modified vector coding technique to describe the calcaneus-shank coupling relationship during unanticipated changes of direction: theoretical implications for prophylactic ACL strategies

Shank rotation is associated with increased risk in lower limb injuries of weight-bearing sport activity. Straight-line running injury prevention research proposes a 'bottom-up' approach to minimising injury risk to the knee. This prophylactic recommendation is due to the observed distal-proximal coupling relationship between rearfoot and shank rotations. However, the coupling relationship between the calcaneus and shank is unknown in sports with high intensity decelerations, frequent changes of direction, associated with increased anterior cruciate ligament (ACL) injury risk. The aim of this study was to determine whether the movement of the calcaneus has a potential effect on the internal and external rotational movement of the shank, associated with ACL injury risk. We implemented a modified vector coding technique using segmental velocities in a local, anatomical reference frame to quantify the coupling relationship between the individual tri-planar calcaneus rotations and transverse plane shank rotations. During the loading phase, a distal-proximal coupling relationship between calcaneus eversion deceleration, abduction acceleration, and shank internal rotation deceleration was observed amongst most subjects. The distal-proximal coupling found between the calcaneus and shank justifies exploring interventions geared towards manipulating calcaneus motion to affect shank rotational movements during unanticipated change of direction tasks associated with ACL injury risk.

Effect of Systematic Corrective Exercises on the Static and Dynamic Balance of Patients with Pronation Distortion Syndrome: A Randomized Controlled Clinical Trial Study

Background:

The purpose of this study was to determine the effect of systematic corrective exercises on the static and dynamic balance of students with pronation distortion syndrome.

Methods:

In this randomized controlled clinical trial study, 30 volunteers were selected and randomly divided into the control and experimental groups (15 subjects per group). The experimental group performed systematic corrective exercises for 12 weeks, while the control group performed the routine exercise. Static and dynamic balance was evaluated before and after the interventions. The data were analyzed using independent and paired t-tests (P < 0.05).

Results:

The results showed significant improvement (P < 0.05) in the static and dynamic balance in the experimental group, but not in the control group. A significant difference was evident between the experimental and control groups in terms of static and dynamic balances, in static balance including Flamingo balance test (42.26 ± 5.35 vs. 10.13 ± 1.92) stabilometr (1.23 ± 0.48 vs. 3.71 ± 1.02), and in dynamic balance including star excursion balance test (anterior direction 82.4 ± 6.2 vs. 66.7 ± 6.9, Posterior-internal direction 87.8 ± 4.7 vs. 69.6 ± 6.3, posterior-external direction 86.06 ± 6.93 vs. 67.2 ± 6.2), stabilometr (3.8 ± 0.6 vs. 11.18 ± 1.8) (P < 0.05 for all variables).

Conclusions:

It can be concluded that systematic corrective exercises improve static and dynamic balance in students with pronation distortion syndrome and it could be recommended as modalities for these people.

The effect of changing foot progression angle using real-time visual feedback on rearfoot eversion during running

Atypical rearfoot in/eversion may be an important risk factor for running-related injuries. Prominent interventions for atypical rearfoot eversion include foot orthoses, footwear, and taping but a modification derived from gait retraining to correct atypical rearfoot in/eversion is lacking. We aimed to investigate changes in rearfoot in/eversion, subtalar pronation, medial longitudinal arch angle, and selected lower limb joint biomechanics while performing toe-in/toe-out running using real-time visual feedback. Fifteen female runners participated in this study. Subjects performed toe-in/toe-out running using real-time visual feedback on foot progression angle, which was set ±5° from habitual foot progression angle. 3D kinematics of rearfoot in/eversion, subtalar supination/pronation, medial longitudinal arch angle, foot progression angle, hip flexion, ab/adduction and internal/external rotation, knee flexion, ankle dorsiflexion, and ankle power were analyzed. A repeated-measures ANOVA followed by pairwise comparisons was used to analyze changes between three conditions. Toe-in running compared to normal and toe-out running reduced peak rearfoot eversion (mean difference (MD) with normal = 2.1°; p<0.001, MD with toe-out = 3.5°; p<0.001), peak pronation (MD with normal = -2.0°; p<0.001, MD with toe-out = -3.4; p = <0.001), and peak medial longitudinal arch angle (MD with normal = -0.7°; p = 0.022, MD with toe-out = -0.9; p = 0.005). Toe-out running significantly increased these kinematic factors compared to normal and toe-in running. Toe-in running compared to normal running increased peak hip internal rotation (MD = 2.3; p<0.001), and reduced peak knee flexion (MD = 1.3; p = 0.014). Toe-out running compared to normal running reduced peak hip internal rotation (MD = 2.5; p<0.001), peak hip ab/adduction (MD = 2.5; p<0.001), peak knee flexion (MD = 1.5; p = 0.003), peak ankle dorsiflexion (MD = 1.6; p<0.001), and peak ankle power (MD = 1.3; p = 0.001). Runners were able to change their foot progression angle when receiving real-time visual feedback for foot progression angle. Toe-in/toe-out running altered rearfoot kinematics and medial longitudinal arch angle, therefore supporting the potential value of gait retraining focused on foot progression angle using real-time visual feedback when atypical rearfoot in/eversion needs to be modified. It should be considered that changes in foot progression angle when running is accompanied by changes in lower limb joint biomechanics.