Etiology, Prevention, and Early Intervention of Overuse Injuries in Runners: a Biomechanical Perspective

To enhance the shock-absorbing performance of the midsole in conditions where thickness is limited, particularly in the forefoot region, this paper presents a novel design inspired by the structure and material assembly characteristics of ostrich metatarsophalangeal joints and toe pads. The shock-absorbing performance of the bionic unit was validated through finite element simulations and experimental testing using 3D-printed samples. In order to unravel the underlying mechanisms that enhance the cushioning performance, optimization factors for the forefoot bionic cushioning unit were determined based on the cushioning mechanism. The influence of the cantilever angle (La), cantilever taper (Lo), cantilever spacing (L3), thickness of the elastic energy-absorbing component (L4), and selected materials on the cushioning performance was discussed. The results demonstrate that with the configuration of La:Lo:L3:L4 = 60°:0.6:9 mm:3 mm and the outer frame material to elastic energy-absorbing component material ratio of T-4:T-2, compared to the non-optimized unit, the peak negative acceleration of the forefoot bionic unit has been reduced by 32.64%.Based on the optimization results, the production of the bionic cushioning sports shoes and the control shoes was completed. Finally, human wear experiments have shown that the bionic shoes exhibit a 23.7% to 29.8% increase in impact absorption compared to control shoes.

No systematic review has investigated the main biomechanical variables as predictors of running-related injuries.

To investigate the main biomechanical variables associated with running-related injuries.

Medline via PubMed, EMBASE, SPORTDiscus, Web of Science, and CINAHL were searched from inception until 1 November 2021. Each study included must have investigated the association of at least one biomechanical variable (kinetics, kinematics, electromyography, or pressure distribution) with running injuries. The meta-analysis was conducted, and a modified version of the Downs and Black Quality Index was used for methodological quality evaluation.

Across the 82 studies included, 5465 runners were investigated. The meta-analysis was conducted with 11 biomechanical variables from 51 articles (n=2395). The peak hip adduction angle was the sole biomechanical variable associated with running injury and was found to be higher in injured runners (0.57, 95% CI 0.21, 0.94) compared to uninjured runners. However, this result was highly influenced by two studies (out of five studies) conducted by the same group of authors.

Clinicians, coaches, and runners should be aware that minimal evidence supports that alterations of running biomechanics are associated with running-related injuries. Heterogeneity in evaluation conditions and inconsistency in the naming and definitions of biomechanical variables make definitive conclusions challenging.

PROSPERO, CRD42017068839

The pivotal role of biomechanics in the past 50 years in consolidating the basic knowledge that underpins prevention and rehabilitation measures has made this area a great spotlight for health practitioners. In clinical practice, biomechanics analysis of spatiotemporal, kinematic, kinetic, and electromyographic data in various chronic conditions serves to directly enhance deeper understanding of locomotion and the consequences of musculoskeletal dysfunctions in terms of motion and motor control. It also serves to propose straightforward and tailored interventions. The importance of this approach is supported by myriad biomechanical outcomes in clinical trials and by the development of new interventions clearly grounded on biomechanical principles. Over the past five decades, therapeutic interventions have been transformed from fundamentally passive in essence, such as orthoses and footwear, to emphasizing active prevention, including exercise approaches, such as bottom-up and top-down strengthening programs for runners and people with osteoarthritis. These approaches may be far more effective in reducing pain, dysfunction, and, ideally, incidence if they are based on the biomechanical status of the affected person. In this review, we demonstrate evidence of the impact of biomechanics and motion analysis as a foundation for physical therapy/rehabilitation and preventive strategies for three chronic conditions of high worldwide prevalence: diabetes and peripheral neuropathy, knee osteoarthritis, and running-related injuries. We conclude with a summary of recommendations for future studies needed to address current research gaps.

Interval training (IT) is influenced by several variables and its design. However, there is no consensus about the acute effects of this type of training on running kinematics and gait patterns due to the variety of session designs.

The aim of this systematic review was to determine the acute effects of IT on gait patterns and running kinematics in endurance runners depending on the characteristics of the training sessions.

A systematic search on four databases (Pubmed, WOS, Medline, and Scopus) was conducted on February 22, 2022. After analyzing 655 articles, studies were included if they met the inclusion criteria developed according to the PICO model. Nine studies were finally included.

Only two of these studies measured kinematics changes during IT bouts while seven measured pre-post changes of these parameters. The quality scores of the included studies in the review averaged 5.44 (good quality) points using the modified PEDro scale. The observed changes in running kinematics during IT sessions were an increase in stride frequency, contact time and vertical displacement of center of mass.

Regarding the type of IT, anaerobic and short aerobic interval sessions (200–1000 m) should include long recovery periods (2–3 min) to avoid the increase of stride frequency, contact time and vertical oscillation of the center of mass as a results of muscle fatigue. For long aerobic interval sessions (>1000 m), a short recovery (1–2 min) between bouts do not induce a high level of muscle fatigue nor modifications in gait patterns. Coaches and athletes must consider the relative intensity and recovery periods of IT, and the type of IT, to prevent excessive fatigue which can negatively affect running kinematics.

Iliotibialis syndrome is one of the most common types of running injury of the lateral knee. Earlier studies have mainly focused on the relationship between iliotibialis syndrome and hip muscle forces, since the latter are often the target of intervention during rehabilitation. The results suggest that a curved shoe sole may affect lower limb mechanics during running. The main purpose of this study was to assess the effects of different curves of rocker shoes on activation of the musculus gluteus medius and maximus under various running conditions.

Fifteen recreational runners (1.77 ± 0.44 m height, 74.25 ± 6.68 kg weight, 23.73 ± 1.79 kg/m² BMI) were recruited to test three rocker shoes with different forefoot curvatures on a flat laboratory floor and a treadmill at flat, uphill, and downhill gradients. Surface electromyography data were collected for musculus gluteus medius and maximus, resulting in a three-way within-subject design (running condition (4) x shoe (3) x muscle (2)) with 24 measurement combinations for each runner. A linear mixed model was fitted to the data to quantify running condition, shoe curve and muscle effects.

The main effects of running condition, shoe and muscle were estimated. While running uphill, significant decreases were observed in both peak (P = 0.021, log%MVC) and duration (P = 0.015, log%MVC) compared to running on a flat laboratory surface. Both average (0.033 log%MVC) and peak muscle activation (0.069 log%MVC) were increased with a smaller radius of shoe curvature.

In conclusion, the study shows that rocker shoes appear to affect gluteal muscle activation and could potentially assist in stabilising the pelvis during running. This knowledge might be of interest for runners with an increased risk of ITBS and may therefore gain health benefits from wearing rocker shoes.

Le syndrome de l’iliotibialis est l’un des types les plus courants de blessure en course à pied du genou latéral. Les études précédentes se sont principalement concentrées sur la relation entre le syndrome iliotibialis et les forces musculaires de la hanche, puisque ces dernières sont souvent la cible d’interventions lors de la rééducation. Les résultats suggèrent qu’une semelle de chaussure incurvée peut affecter la mécanique des membres inférieurs pendant la course. L’objectif principal de cette étude était d’évaluer les effets de différentes courbes de chaussures à bascule sur l’activation du muscle fessier moyen et du muscle grand fessier dans diverses conditions de course.

Quinze coureurs récréatifs (1,77 ± 0,44 m taille, 74,25 ± 6,68 kg poids, 23,73 ± 1,79 kg/m² BMI) ont été recrutés pour tester trois chaussures à bascule avec différentes courbures de l’avant-pied sur un sol de laboratoire plat et un tapis roulant à plat, en montée et en descente. Des données d’électromyographie de surface ont été recueillies pour le musculus gluteus medius et le maximus, ce qui a permis d’obtenir une conception à trois voies au sein du sujet (condition de course (4) x chaussure (3) x muscle (2)) avec 24 combinaisons de mesures pour chaque coureur. Un modèle linéaire mixte a été adapté aux données pour quantifier les effets de la condition de course, de la courbe de la chaussure et du muscle.

Les principaux effets de la condition de course, de la chaussure et du muscle ont été estimés. Lors de la course en montée, des diminutions significatives ont été observées tant au niveau du pic (p = 0,021, log%MVC) que de la durée (p = 0,015, log%MVC) par rapport à la course sur une surface plane de laboratoire. L’activation musculaire moyenne (0,033 log%MVC) et maximale (0,069 log%MVC) a augmenté avec un rayon de courbure de la chaussure plus petit.

En conclusion, l’étude montre que les chaussures à bascule semblent affecter l’activation des muscles fessiers et pourraient potentiellement aider à stabiliser le bassin pendant la course. Cette connaissance pourrait être intéressante pour les coureurs présentant un risque accru de SII et qui pourraient donc tirer des avantages pour leur santé du port de chaussures à bascule.

Runners have a high risk of acquiring a running-related injury. Understanding the mechanisms of impact force attenuation into the body when a runner fatigues might give insight into the role of running kinematics on the aetiology of overuse injuries.

How do running kinematics change due to running-induced fatigue? And what is the influence of experience level on changes in running kinematics due to fatigue?

Three electronic databases were searched: PubMed, Web of Science, and Scopus. This resulted in 33 articles and 19 kinematic quantities being included in this review. A quality assessment was performed on all included articles and meta-analyses were performed for 18 kinematic quantities.

Main findings included an increase in peak acceleration at the tibia and a decrease in leg stiffness after a fatiguing protocol. Additionally, level running-induced fatigue increased knee flexion at initial contact and maximum knee flexion during swing. An increase in vertical centre of mass displacement was found in novice but not in experienced runners with fatigue. Overall, runners changed their gait pattern due to fatigue by moving to a smoother gait pattern (i.e. more knee flexion at initial contact and during swing, decreased leg stiffness). However, these changes were not sufficient to prevent an increase in peak accelerations at the tibia after a fatigue protocol. Large inter-individual differences in responses to fatigue were reported. Hence, it is recommended to investigate changes in running kinematics as a result of fatigue on a subject-specific level since group-level analysis might mask individual responses.