Is There a Pathological Gait Associated With Common Soft Tissue Running Injuries?

Can Foot Orthoses Benefit Symptomatic Runners? Mechanistic and Clinical Insights Through a Scoping Review

BACKGROUND

Running is a widely practiced sport worldwide associated with a host of benefits on cardiovascular, metabolic, musculoskeletal, and mental health, but often leads to musculoskeletal overuse injuries. The prescription of a foot orthosis (FO) is common to manage musculoskeletal impairments during physical activity or functional tasks. Although FOs are frequently prescribed by clinicians for symptomatic populations of runners, the existing literature supporting the prescription of FOs in runners has predominantly focused on either uninjured individuals or a mix of uninjured and symptomatic populations. Thus, the effects of FOs on the treatment and/or prevention of overuse running injuries need to be investigated to guide future research and assist clinicians in their decision-making process.

MAIN BODY

This scoping review aimed to evaluate the immediate and long-term effects of FOs on lower limb biomechanics, neuromuscular parameters, and pain and disability in symptomatic runners, and to identify factors that may influence the effects of FOs. Five databases (CINAHL, SPORTDiscus, MEDLINE, Embase, and Web of Science) were searched, resulting in 2536 studies. A total of 30 studies, published between 1992 and 2023 (730 symptomatic runners), were included following the removal of duplicates and the screening process. Wearing FOs while running is related to an immediate and a long-term decrease in pain and symptoms of overuse running injuries. Also, wearing FOs while running decreases eversion at the foot/ankle complex, leads to a more lateral plantar pressure at the heel and forefoot, and may change running motor control strategies. Finally, the effectiveness of FOs is influenced by its added features.

CONCLUSIONS

This study provides recommendations for future research such as the need for standardized methods in describing FOs, considering participant characteristics such as foot morphology, and comparing different types of FOs. Also, this scoping review provides valuable insights for guiding the prescription and design of FOs, and suggests that integrating FOs into a comprehensive treatment plan may yield better results than standalone first-line treatments. Nonetheless, this scoping review highlights the need for future research to explore the optimal integration of FOs into injury-specific treatment plans.

Is Achilles tendon structure associated with functional ability and chronic ankle instability in military recruits?

OBJECTIVE

To determine the relationship between Achilles tendon (AT) structure, functional ability and chronic ankle instability (CAI) in military recruits.

METHODS

Three hundred and sixty newly recruited infantry male soldiers recruited in April 2022 were assessed for AT structure by Ultrasound Tissue Characterization (UTC), for functional abilities (included proprioception ability, heel-raise test, dynamic postural balance, and hopping agility ability) and for CAI (recurrent sprains and a positive perceived instability).

RESULTS

Soldiers that were identified with disorganized tendon had significantly lower heel-raise and agility scores compared to those with organized tendon structures (33.6 ± 18.1(n) vs. 49.9 ± 28.9(n), p < 0.001; and 5.39 ± 2.12(n) vs. 6.16 ± 1.90(n), p = 0.002, respectively). The best discriminator between soldiers with organized vs. disorganized structure, was heel-raise test (AUC = 0.741). Moreover, soldiers with disorganized AT structure had a higher prevalence of CAI compared with those with organized tendon structures (p < 0.05).

CONCLUSION

Recruits with disorganized tendon structures displayed reduced heel-raise score, agility ability and dynamic postural-balance and greater ankle instability. Inferior tendon quality at the onset of military service is an important physical indicator to consider when seeking to manage future injuries and potential for physical performance. Pre-recruitment screening of the AT structure, CAI, and functional abilities, especially in high-intensity infantry programs, needs to be considered.

Biomechanics of human locomotion in the wind

In laboratory settings, human locomotion encounters minimal opposition from air resistance. However, moving in nature often requires overcoming airflow. Here, the drag force exerted on the body by different headwind or tailwind speeds (between 0 and 15 m·s-1) was measured during walking at 1.5 m·s-1 and running at 4 m·s-1. To our knowledge, the biomechanical effect of drag in human locomotion has only been evaluated by simulations. Data were collected on eight male subjects using an instrumented treadmill placed in a wind tunnel. From the ground reaction forces, the drag and external work done to overcome wind resistance and to sustain the motion of the center of mass of the body were measured. Drag increased with wind speed: a 15 m·s-1 headwind exerted a drag of ∼60 N in walking and ∼50 N in running. The same tailwind exerted -55 N of drag in both gaits. At this wind speed, the work done to overcome the airflow represented ∼80% of the external work in walking and ∼50% in running. Furthermore, in the presence of fast wind speeds, subjects altered their drag area (CdA) by adapting their posture to limit the increase in air friction. Moving in the wind modified the ratio between positive and negative external work performed. The modifications observed when moving with a head- or tailwind have been compared with moving uphill or downhill. The present findings may have implications for optimizing aerodynamic performance in competitive running, whether in sprints or marathons.NEW & NOTEWORTHY This is the first study to assess the biomechanical adaptations to a wide range of wind speeds inside a wind tunnel. Humans increase their mechanical work and alter their drag area (CdA) by adapting their posture when walking and running against increasing head and tailwinds. The observed drag force applied to the subject is different between walking and running at similar headwind speeds.

Test-retest reliability and minimal detectable change in pelvis and lower limb coordination during running assessed with modified vector coding

The objective of this study was to evaluate the reliability of Modified Vector Coding in assessing the coordination and coordination variability of the lower limbs and pelvis during running and to determine the Minimal Detectable Change (MDC). Twenty-five healthy runners participated in a biomechanical analysis of treadmill running using a motion capture system. Modified vector coding was applied to assess the three-dimensional coordination among various pelvis and lower limb segmental couplings. Reliability was assessed using the Intraclass Correlation Coefficient (ICC), Standard Error of Measurement (SEM), MDC, and Bland-Altman analysis to ascertain measurement consistency, agreement, and the smallest clinically meaningful change that exceeds measurement error. The test-retest reliability for 33 of 42 segmental couplings analyzed was good to excellent, with ICC values ranging from 0.613 to 0.928 (p <0.05), which substantiates the robustness of modified vector coding in running biomechanics. However, nine couplings, particularly femur-tibia in the sagittal plane during midstance and foot in the frontal plane-tibia in the transverse plane during late stance, exhibited poor to moderate reliability. These findings underscore the need for cautious interpretation due to significant proportional bias (p <0.05). SEM and MDC provided insights into the precision and minimal clinically significant changes for each coupling. The findings confirm the reliability of modified vector coding for biomechanical analysis in running, with most couplings demonstrating consistent high reliability. Nevertheless, specific couplings should be interpreted with caution due to potential measurement errors. The application of MDC highlights the precision of modified vector coding in biomechanical analyses and emphasizes the importance of careful interpretation to improve clinical and research outcomes in running-related injuries.

Is There a Pathologic Running Motion Associated with Running-Related Injuries? A Methodological Study Using a Motion Analysis System Without Sensors

(1) Background and objectives: Running-related injuries (RRIs) are commonly attributed to improper running posture and overuse. This study aims to analyze the running motions of individuals with and without RRIs using a sensor-free method, which offers a user-friendly and straightforward approach. (2) Materials and Methods: A total of 155 runners were divided into two groups: the normal runner group (runners who had never been injured, n = 50) and the RRI group (runners who had experience at least one injury while running, n = 105). The forward head posture (FHP), trunk lean, hip rotation, horizontal movement of the center of gravity (COG), vertical movement of the COG, pelvic rotation, hip hike, and type of strike were measured for posture analysis. (3) Results: We found that the left-right balance of the pelvis and the spinal posture during running were associated with RRIs. The difference in hip hike and FHP emerged as key predictors of running-related musculoskeletal injury occurrence from our logistic regression analysis. (4) Conclusions: Identifying pathological movements in runners through running motion analysis without the use of sensors can be instrumental in the prevention and treatment of RRIs.

Clustering analysis across different speeds reveals two distinct running techniques with no differences in running economy

Establishing the links between running technique and economy remains elusive due to high inter-individual variability. Clustering runners by technique may enable tailored training recommendations, yet it is unclear if different techniques are equally economical and whether clusters are speed-dependent. This study aimed to identify clusters of runners based on technique and to compare cluster kinematics and running economy. Additionally, we examined the agreement of clustering partitions of the same runners at different speeds. Trunk and lower-body kinematics were captured from 84 trained runners at different speeds on a treadmill. We used Principal Component Analysis for dimensionality reduction and agglomerative hierarchical clustering to identify groups of runners with a similar technique, and we evaluated cluster agreement across speeds. Clustering runners at different speeds independently produced different partitions, suggesting single speed clustering can fail to capture the full speed profile of a runner. The two clusters identified using data from the whole range of speeds showed differences in pelvis tilt and duty factor. In agreement with self-optimisation theories, there were no differences in running economy, and no differences in participants' characteristics between clusters. Considering inter-individual technique variability may enhance the efficacy of training designs as opposed to 'one size fits all' approaches.

Gait biomechanics do not differ between adolescents with and without patellofemoral pain

OBJECTIVES

To determine if adolescents with patellofemoral pain exhibit different biomechanical characteristics to asymptomatic adolescents during walking and running.

METHODS

Twenty-eight adolescents with patellofemoral pain (16 male, 12 female, mean [SD] age: 14.3 [1.7] years) and 24 asymptomatic adolescents (13 male, 11 female, mean [SD] age: 14.1 [1.6] years) participated. Participants walked and ran on an instrumented treadmill in a standardized athletic shoe. Continuous hip, knee, and ankle joint angles and moments, and frontal plane pelvic motion were compared between groups using one-dimensional statistical parametric mapping independent t-tests (alpha <0.05). Cadence and stride length were compared between groups using independent t-tests.

RESULTS

During walking, adolescents with patellofemoral pain had a higher hip extension moment at 7%-8% of the gait cycle (p = 0.04) and walked with a shorter stride length (mean difference [95% confidence interval] = -0.07 [-0.1, -0.01] m). There were no other differences between groups during walking. During running, adolescents with patellofemoral pain had greater knee flexion than asymptomatic adolescents at 35%-40% of the gait cycle (p = 0.04) and ran with a higher cadence (mean difference [95% confidence interval] = 5.8 [2.0, 9.5] steps/min). There were no other statistically significant differences between groups during running.

CONCLUSIONS

Adolescents with patellofemoral pain demonstrate few biomechanical differences to asymptomatic adolescents during walking and running. The identified differences are likely of limited clinical importance. Biomechanical alterations which have been previously associated with patellofemoral pain in adults, may not need to be the target of management of adolescent patellofemoral pain.

Preinjury Knee and Ankle Mechanics during Running Are Reduced among Collegiate Runners Who Develop Achilles Tendinopathy

INTRODUCTION

Achilles tendinopathies (AT) are common in runners, but prospective data assessing running mechanics associated with developing AT are limited. Asymmetry in running mechanics is also considered a risk factor for injury, although it is unknown if the problematic mechanics occur on the injured limb only or are present bilaterally.

PURPOSE

This study aimed to prospectively identify differences in preinjury running biomechanics in collegiate runners who did and did not develop AT and determine if between-limb asymmetries were associated with which limb developed AT.

METHODS

Running gait data were obtained preseason on healthy collegiate cross-country runners, and AT incidence was prospectively recorded each year. Spatiotemporal, ground reaction forces, and joint kinematics and kinetics were analyzed. Linear mixed-effects models assessed differences in biomechanics between those who did and did not develop AT during the subsequent year. Generalized linear mixed-effects models determined if the asymmetry direction was associated with which limb developed an AT, with odds ratios (OR) and 95% confidence intervals (95% CI) reported.

RESULTS

Data from 106 runners were analyzed and 15 developed AT. Preinjury biomechanics of runners who developed AT showed less peak knee flexion (noninjured: 45.9° (45.2°-46.6°), injured: 43.2° (41.5°-44.9°), P < 0.001), ankle dorsiflexion (noninjured: 28.7° (28.0°-30.2°), injured: 26.0° (23.8°-28.3°), P = 0.01), and knee extensor moment (noninjured: -2.18 (N·m)·kg -1 (-2.24 to -2.12 (N·m)·kg -1 ), injured: -2.00 (N·m)·kg -1 (-2.17 to -1.84 (N·m)·kg -1 ), P = 0.02). The limb demonstrating less peak knee flexion had greater odds of sustaining an AT (OR, 1.29 (1.00-1.65), P = 0.05).

CONCLUSIONS

Knee and ankle kinematics, in addition to knee kinetics, were associated with developing an AT. Monitoring these mechanics may be useful for prospectively identifying runners at risk of developing AT.

Association between Self-reported Sleep Quality and Single-task Gait in Young Adults: A Study Using Machine Learning

Objective  The objective of the present study was to find biomechanical correlates of single-task gait and self-reported sleep quality in a healthy, young population by replicating a recently published study. Materials and Methods  Young adults ( n  = 123) were recruited and were asked to complete the Pittsburgh Sleep Quality Inventory to assess sleep quality. Gait variables ( n  = 53) were recorded using a wearable inertial measurement sensor system on an indoor track. The data were split into training and test sets and then different machine learning models were applied. A post-hoc analysis of covariance (ANCOVA) was used to find statistically significant differences in gait variables between good and poor sleepers. Results  AdaBoost models reported the highest correlation coefficient (0.77), with Support-Vector classifiers reporting the highest accuracy (62%). The most important features associated with poor sleep quality related to pelvic tilt and gait initiation. This indicates that overall poor sleepers have decreased pelvic tilt angle changes, specifically when initiating gait coming out of turns (first step pelvic tilt angle) and demonstrate difficulty maintaining gait speed. Discussion  The results of the present study indicate that when using traditional gait variables, single-task gait has poor accuracy prediction for subjective sleep quality in young adults. Although the associations in the study are not as strong as those previously reported, they do provide insight into how gait varies in individuals who report poor sleep hygiene. Future studies should use larger samples to determine whether single task-gait may help predict objective measures of sleep quality especially in a repeated measures or longitudinal or intervention framework.

Validity and reliability of the DANU sports system for walking and running gait assessment

Objective. Gait assessments have traditionally been analysed in laboratory settings, but this may not reflect natural gait. Wearable technology may offer an alternative due to its versatility. The purpose of the study was to establish the validity and reliability of temporal gait outcomes calculated by the DANU sports system, against a 3D motion capture reference system.Approach. Forty-one healthy adults (26 M, 15 F, age 36.4 ± 11.8 years) completed a series of overground walking and jogging trials and 60 s treadmill walking and running trials at various speeds (8-14 km hr-1), participants returned for a second testing session to repeat the same testing.Main results. For validity, 1406 steps and 613 trials during overground and across all treadmill trials were analysed respectively. Temporal outcomes generated by the DANU sports system included ground contact time, swing time and stride time all demonstrated excellent agreement compared to the laboratory reference (intraclass correlation coefficient (ICC) > 0.900), aside from ground contact time during overground jogging which had good agreement (ICC = 0.778). For reliability, 666 overground and 511 treadmill trials across all speeds were examined. Test re-test agreement was excellent for all outcomes across treadmill trials (ICC > 0.900), except for swing time during treadmill walking which had good agreement (ICC = 0.886). Overground trials demonstrated moderate to good test re-test agreement (ICC = 0.672-0.750), which may be due to inherent variability of self-selected (rather than treadmill set) pacing between sessions.Significance. Overall, this study showed that temporal gait outcomes from the DANU Sports System had good to excellent validity and moderate to excellent reliability in healthy adults compared to an established laboratory reference.

The Association of Joint Power Kinetic Variables with Running Injuries: A Case-Control Study

Background

There is conflicting data on which kinetic variables are important to consider with running injuries. Furthermore, less is understood regarding differences in these variables when considering demographics such as age, sex, weight, and running speed. The primary question was what joint power kinetic variables were different between non-injured and injured runners.

Purpose

The purpose of this study was to identify if there were differences in joint power kinetic variables between non-injured runners and injured runners.

Study Design

Case-Control Study.

Methods

Kinetic data were collected on 122 runners (26 non-injured and 96 injured) over three years with a Bertec force plated treadmill and Qualisys 3D motion capture. The subjects were considered eligible if they self-identified themselves as runners or had running as a key component of their activity. The subjects ran at a comfortable, self-selected pace while two 10-second trials of recordings were used to calculate the means of peak power generated at the hips, knees, and ankles of each gait cycle. Foot strike was categorized by kinematic data. Two sample T-tests were used to compare peak power variables at the hips, knees, and ankles between non-injured and injured runners. Logistic regression analyses examined how a combination of demographics and peak power variables were associated with injuries.

Results

No peak power variable at the hip, knee, or ankle was significantly different between injured and non-injured runners (p=0.07-0.87). However, higher hip power absorbed was found to be protective against injuries (odds ratio, .16; 95% CI .025-.88) when considering demographics using a logistic regression model including sex, foot strike, BMI, speed, age, and power variables from the hip, knee, and ankle. The area under the ROC curve was .74, which is acceptable discrimination.

Conclusion

When controlling for age, sex, BMI, foot strike, and speed; higher hip power absorbed was found to be protective against injury. This could be due to the hip muscles' unique role in absorbing force during early stance phase.

Level of Evidence

3b©The Author(s).

Running-Related Achilles Tendon Injury: A Prospective Biomechanical Study in Recreational Runners

There are relatively few running studies that have attempted to prospectively identify biomechanical risk factors associated with Achilles tendon (AT) injuries. Therefore, the aim was to prospectively determine potential running biomechanical risk factors associated with the development of AT injuries in recreational, healthy runners. At study entry, 108 participants completed a set of questionnaires. They underwent an analysis of their running biomechanics at self-selected running speed. The incidence of AT running-related injuries (RRI) was assessed after 1-year using a weekly questionnaire standardized for RRI. Potential biomechanical risk factors for the development of AT RRI injury were identified using multivariable logistic regression. Of the 103 participants, 25% of the sample (15 males and 11 females) reported an AT RRI on the right lower limb during the 1-year evaluation period. A more flexed knee at initial contact (odds ratio = 1.146, P = .034) and at the midstance phase (odds ratio = 1.143, P = .037) were significant predictors for developing AT RRI. The results suggested that a 1-degree increase in knee flexion at initial contact and midstance was associated with a 15% increase in the risk of an AT RRI, thus causing a limitation of training or a stoppage of running in runners.

Relationships between tibial accelerations and ground reaction forces during walking with load carriage

Peak tibial accelerations (TAs) during running are strongly related to early stance vertical ground reaction forces (GRFs), which are associated with musculoskeletal injury. However, few studies have examined these correlations during walking, and none have evaluated them during walking with loads, a relevant activity for military personnel. Our purpose was to determine the relationships between GRFs and TAs in US Army trainees (n = 649) walking with loads. An inertial measurement unit was attached over their distal antero-medial tibia. Participants walked on an instrumented treadmill at 1.21-1.34 m/s, with a pack loaded with 18.1 kg, for a 3-min warm-up followed by a minimum of 14 strides of data collection. Simple linear regression models were calculated for peak vertical and resultant TAs with vertical and posterior GRF loading rates and peak forces. The strongest relationships were between vertical loading rates and peak vertical TA (R = 0.43-0.50), however the relationships were weaker than has been reported for unloaded walking and running (R > 0.7). All other relationships were trivial to small (R = 0.06-0.27). The weaker relationships for vertical GRFs and TAs may be due to methodological differences between studies, or differences in gait mechanics, such as a longer double-limb support phase in loaded vs. unloaded walking.

Exploring variations in gait patterns and joint motion characteristics in school-aged children across different walking speeds: a comprehensive motion analysis study

This study aimed to investigate differences in gait patterns among individuals with different walking speeds and identify the range of motion (ROM) and angular velocity for various joints during gait. Forty-five schoolchildren were randomly selected for this study. To capture their walking patterns, two FDR-AX700 4K HDR camcorders were positioned to observe the predetermined walkway. Each participant completed a 5-meter walk at various speeds, including slow, normal, and fast, while maintaining a straight stride. There were significantly higher ROM and angular velocity (p<0.05) at the hip, knee, and ankle joints across most stages of walking at a faster speed compared to slow and normal speeds. At the same time, the angular velocity was significantly higher at the hip joint during hip extension terminal stance at normal speed compared to slow and fast speeds (p<0.05, ƞ2 =0.74). Similarly, the ROM of knee flexion swing, ankle plantar flexion loading response, and ankle dorsiflexion midswing angular velocity were significantly higher during normal walking speed (p<0.05). Conversely, slow-speed walking showed significantly higher ROM at knee extension terminal swing (ƞ2=0.52) and ankle dorsiflexion terminal stance (ƞ2=0.78) (p<0.05). The results indicate that individuals with different walking speeds exhibit significant differences in gait patterns. Slower walking speeds resulted in lower gait velocity and different joint motions compared to faster walking speeds.

Lower extremity kinematics during running and hip abductor strength in iliotibial band syndrome: A systematic review and meta-analysis

BACKGROUND

Iliotibial band syndrome is a common overuse injury that is twice as likely to affect female runners compared to male runners. It is unclear if there is a consistent running pattern and strength profile exhibited by female and male runners with iliotibial band syndrome.

RESEARCH QUESTION

The purpose of this systematic review and meta-analysis was to determine if any differences existed in lower-extremity kinematics and hip strength between runners who retrospectively, currently, or prospectively had iliotibial band syndrome.

METHODS

Papers included must have reported three-dimensional kinematic running data and/or hip strength data that were statistically analyzed between runners that never developed iliotibial band syndrome and runners with iliotibial band syndrome. Meta-analysis was performed for each kinematic or strength variable reported in at least three studies. Female and male runners were analyzed separately and grouped into three cohorts (retrospective, current, prospective).

RESULTS

Seventeen articles were included in this systematic review. Data from 10 cross-sectional studies were included for meta-analysis. Female runners with current iliotibial band syndrome exhibited smaller peak hip internal rotation angles and lower isometric hip abductor strength compared to controls.

SIGNIFICANCE

Although limited biomechanical evidence exists, risk factors for ITBS are different between female and male runners and may vary according to injury status. Specifically, transverse plane hip motion and hip abductor strength weakness may be biomechanical risk factors in female runners with current iliotibial band syndrome only.

Silicone Elastomeric-Based Materials of Soft Pneumatic Actuator for Lower-Limb Rehabilitation: Finite Element Modelling and Prototype Experimental Validation

This study describes the basic design, material selection, fabrication, and evaluation of soft pneumatic actuators (SPA) for lower-limb rehabilitation compression therapy. SPAs can be a promising technology in proactive pressure delivery, with a wide range of dosages for treating venous-related diseases. However, the most effective design and material selection of SPAs for dynamic pressure delivery have not been fully explored. Therefore, a SPA chamber with two elastomeric layers was developed for this study, with single-side inflation. The 3D deformation profiles of the SPA chamber using three different elastomeric rubbers were analyzed using the finite element method (FEM). The best SPA-compliant behavior was displayed by food-grade silicone A10 Shore with a maximum deformation value of 25.34 mm. Next, the SPA chamber was fabricated using A10 Shore silicone and experimentally validated. During the simulation in FEM, the air pressure was applied on the inner wall of the chamber (i.e., the affected area). This is to ensure the applied pressure was evenly distributed in the inner wall while the outer wall of the chamber remained undeformed for all compression levels. During the inflation process, pressure will be applied to the SPA chamber, causing exerted pressure on the skin which is then measured for comparison. The simulation and experimental results show an excellent agreement of pressure transmission on the skin for the pressure range of 0–120 mmHg, as depicted in the Bland–Altman plots. The findings exhibited promising results in the development of the SPA chamber using low-cost and biocompatible food-grade silicone.

Biomechanical characteristics of the lower extremities during running in male long-distance runners with a history of medial tibial stress syndrome: a case control study

BACKGROUND

Medial tibial stress syndrome (MTSS) is a running-related injury of the lower extremities. After returning to competition, there are often recurring episodes of MTSS. Therefore, it is important to prevent the onset and recurrence of MTSS among long-distance runners. This case-control study aimed to compare the kinematics and kinetics of runners with and without previous MTSS during running to clarify the biomechanical characteristics of the lower extremity of runners with previous MTSS.

METHODS

Thirteen male long-distance runners aged over 18 years and asymptomatic at the time of measurement were divided into an MTSS group and a non-MTSS group based on their history of MTSS as reported in a questionnaire. The kinetics and kinematics of running were analyzed when participants ran at a speed of 2.0 ± 0.2 m/s by a three-dimensional motion analysis system and two force plates. Data regarding the joint angles, moments, and powers of the ankle, knee, and hip during the stance phase while running were extracted and compared between the two groups using the Mann-Whitney U test.

RESULTS

Of the 13 participants, 5 and 8 were included in the MTSS (10 legs) and non-MTSS (16 legs) groups, respectively. The ankle maximum eversion moment was significantly larger in the MTSS group than in the non-MTSS group (p = 0.04). There were no significant differences in other parameters.

CONCLUSIONS

This study found that the ankle maximum eversion moment during the stance phase of running was larger in the MTSS group than in the non-MTSS group. Even after the disappearance of the symptoms of MTSS, the running biomechanics of participants with previous MTSS differed from those of participants without previous MTSS.

Kinematic and Kinetic Gait Characteristics in People with Patellofemoral Pain: A Systematic Review and Meta-analysis

BACKGROUND

Patellofemoral pain (PFP) is a prevalent knee condition with many proposed biomechanically orientated etiological factors and treatments.

OBJECTIVE

We aimed to systematically review and synthesize the evidence for biomechanical variables (spatiotemporal, kinematic, kinetic) during walking and running in people with PFP compared with pain-free controls, and determine if biomechanical variables contribute to the development of PFP.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

We searched Medline, CINAHL, SPORTDiscus, Embase, and Web of Science from inception to October 2021.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

All study designs (prospective, case-control [± interventional component, provided pre-intervention data were reported for both groups], cross-sectional) comparing spatiotemporal, kinematic, and/or kinetic variables during walking and/or running between people with and without PFP.

RESULTS

We identified 55 studies involving 1300 people with PFP and 1393 pain-free controls. Overall pooled analysis identified that people with PFP had slower gait velocity [moderate evidence, standardized mean difference (SMD) - 0.50, 95% confidence interval (CI) - 0.72, - 0.27], lower cadence (limited evidence, SMD - 0.43, 95% CI - 0.74, - 0.12), and shorter stride length (limited evidence, SMD - 0.46, 95% CI - 0.80, - 0.12). People with PFP also had greater peak contralateral pelvic drop (moderate evidence, SMD - 0.46, 95% CI - 0.90, - 0.03), smaller peak knee flexion angles (moderate evidence, SMD - 0.30, 95% CI - 0.52, - 0.08), and smaller peak knee extension moments (limited evidence, SMD - 0.41, 95% CI - 0.75, - 0.07) compared with controls. Females with PFP had greater peak hip flexion (moderate evidence, SMD 0.83, 95% CI 0.30, 1.36) and rearfoot eversion (limited evidence, SMD 0.59, 95% CI 0.03, 1.14) angles compared to pain-free females. No significant between-group differences were identified for all other biomechanical variables. Data pooling was not possible for prospective studies.

CONCLUSION

A limited number of biomechanical differences exist when comparing people with and without PFP, mostly characterized by small-to-moderate effect sizes. People with PFP ambulate slower, with lower cadence and a shortened stride length, greater contralateral pelvic drop, and lower knee flexion angles and knee extension moments. It is unclear whether these features are present prior to PFP onset or occur as pain-compensatory movement strategies given the lack of prospective data.

TRIAL REGISTRATION

PROSPERO # CRD42019080241.

Biomechanics and lower limb function are altered in athletes and runners with achilles tendinopathy compared with healthy controls: A systematic review

Achilles tendinopathy (AT) is a debilitating injury in athletes, especially for those engaged in repetitive stretch-shortening cycle activities. Clinical risk factors are numerous, but it has been suggested that altered biomechanics might be associated with AT. No systematic review has been conducted investigating these biomechanical alterations in specifically athletic populations. Therefore, the aim of this systematic review was to compare the lower-limb biomechanics of athletes with AT to athletically matched asymptomatic controls. Databases were searched for relevant studies investigating biomechanics during gait activities and other motor tasks such as hopping, isolated strength tasks, and reflex responses. Inclusion criteria for studies were an AT diagnosis in at least one group, cross-sectional or prospective data, at least one outcome comparing biomechanical data between an AT and healthy group, and athletic populations. Studies were excluded if patients had Achilles tendon rupture/surgery, participants reported injuries other than AT, and when only within-subject data was available.. Effect sizes (Cohen's d) with 95% confidence intervals were calculated for relevant outcomes. The initial search yielded 4,442 studies. After screening, twenty studies (775 total participants) were synthesised, reporting on a wide range of biomechanical outcomes. Females were under-represented and patients in the AT group were three years older on average. Biomechanical alterations were identified in some studies during running, hopping, jumping, strength tasks and reflex activity. Equally, several biomechanical variables studied were not associated with AT in included studies, indicating a conflicting picture. Kinematics in AT patients appeared to be altered in the lower limb, potentially indicating a pattern of "medial collapse". Muscular activity of the calf and hips was different between groups, whereby AT patients exhibited greater calf electromyographic amplitudes despite lower plantar flexor strength. Overall, dynamic maximal strength of the plantar flexors, and isometric strength of the hips might be reduced in the AT group. This systematic review reports on several biomechanical alterations in athletes with AT. With further research, these factors could potentially form treatment targets for clinicians, although clinical approaches should take other contributing health factors into account. The studies included were of low quality, and currently no solid conclusions can be drawn.

Trunk Biomechanics in Individuals with Knee Disorders: A Systematic Review with Evidence Gap Map and Meta-analysis

BACKGROUND

The trunk is the foundation for transfer and dissipation of forces throughout the lower extremity kinetic chain. Individuals with knee disorders may employ trunk biomechanical adaptations to accommodate forces at the knee or compensate for muscle weakness. This systematic review aimed to synthesize the literature comparing trunk biomechanics between individuals with knee disorders and injury-free controls.

METHODS

Five databases were searched from inception to January 2022. Observational studies comparing trunk kinematics or kinetics during weight-bearing tasks (e.g., stair negotiation, walking, running, landings) between individuals with knee disorders and controls were included. Meta-analyses for each knee disorder were performed. Outcome-level certainty was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE), and evidence gap maps were created.

RESULTS

A total of 81 studies investigating trunk biomechanics across six different knee disorders were included (i.e., knee osteoarthritis [OA], total knee arthroplasty [TKA], patellofemoral pain [PFP], patellar tendinopathy [PT], anterior cruciate ligament deficiency [ACLD], and anterior cruciate ligament reconstruction [ACLR]). Individuals with knee OA presented greater trunk flexion during squatting (SMD 0.88, 95% CI 0.58-1.18) and stepping tasks (SMD 0.56, 95% CI 0.13-.99); ipsilateral and contralateral trunk lean during walking (SMD 1.36; 95% CI 0.60-2.11) and sit-to-stand (SMD 1.49; 95% CI 0.90-2.08), respectively. Greater trunk flexion during landing tasks in individuals with PFP (SMD 0.56; 95% CI 0.01-1.12) or ACLR (SMD 0.48; 95% CI 0.21-.75) and greater ipsilateral trunk lean during single-leg squat in individuals with PFP (SMD 1.01; 95% CI 0.33-1.70) were also identified. No alterations in trunk kinematics of individuals with TKA were identified. Evidence gap maps outlined the lack of investigations for individuals with PT or ACLD, as well as for trunk kinetics across knee disorders.

CONCLUSION

Individuals with knee OA, PFP, or ACLR present with altered trunk kinematics in the sagittal and frontal planes. The findings of this review support the assessment of trunk biomechanics in these individuals in order to identify possible targets for rehabilitation and avoidance strategies.

TRIAL REGISTRATION

PROSPERO registration number: CRD42019129257.

The effect of fatigue on the ankle and knee kinematics and kinetics in moderately and highly trained healthy non-rearfoot runners

The aim of this study was to compare selected ankle and knee kinematic and kinetic parameters before and a fter a prolonged exhaustive treadmill run between two groups of non-rearfoot footstrike pattern (NRFP) runners with different training volumes. Twenty-eight habitual NRFP runners were assigned to two groups based on their weekly training volume (Highly-trained (HT)/Moderately-trained (MT)). Participants underwent the VO2max test, and the exhaustive treadmill ran with biomechanical analysis at the beginning and the end. The two-way RMANOVA was used to assess differences between the groups and the phase of the run. A paired t-test was used for post-hoc analysis in case of significant interaction effect. Kinetic results showed significant group effect for ankle plantarflexion moment and hip external rotation moment (end-phase: both greater in MT group). Kinematic results showed significant group×phase interaction for ankle dorsiflexion angle (end-phase: greater in MT group) at initial contact (IC), peak knee flexion angle (end-phase: greater in MT group), and peak ankle eversion angle during the stance phase (end-phase: greater in HT group). Additionally, a group effect was found for knee flexion angle at IC (end-phase: greater in HT group). This study suggests that HT healthy NRFP runners may have less potential for increased biomechanical risk of AT overload during an exhaustive run.

Healthy Running Habits for the Distance Runner: Clinical Utility of the American College of Sports Medicine Infographic

ABSTRACT

Healthy running form is characterized by motion that minimizes mechanical musculoskeletal injury risks and improves coactivation of muscles that can buffer impact loading and reduce stresses related to chronic musculoskeletal pain. The American College of Sports Medicine Consumer Outreach Committee recently launched an infographic that describes several healthy habits for the general distance runner. This review provides the supporting evidence, expected acute motion changes with use, and practical considerations for clinical use in patient cases. Healthy habits include: taking short, quick, and soft steps; abdominal bracing; elevating cadence; linearizing arm swing; controlling forward trunk lean, and; avoiding running through fatigue. Introduction of these habits can be done sequentially one at a time to build on form, or more than one over time. Adoption can be supported by various feedback forms and cueing. These habits are most successful against injury when coupled with regular dynamic strengthening of the kinetic chain, adequate recovery with training, and appropriate shoe wear.

Clinical Application of Gait Retraining in the Injured Runner

Despite its positive influence on physical and mental wellbeing, running is associated with a high incidence of musculoskeletal injury. Potential modifiable risk factors for running-related injury have been identified, including running biomechanics. Gait retraining is used to address these biomechanical risk factors in injured runners. While recent systematic reviews of biomechanical risk factors for running-related injury and gait retraining have been conducted, there is a lack of information surrounding the translation of gait retraining for injured runners into clinical settings. Gait retraining studies in patients with patellofemoral pain syndrome have shown a decrease in pain and increase in functionality through increasing cadence, decreasing hip adduction, transitioning to a non-rearfoot strike pattern, increasing forward trunk lean, or a combination of some of these techniques. This literature suggests that gait retraining could be applied to the treatment of other injuries in runners, although there is limited evidence to support this specific to other running-related injuries. Components of successful gait retraining to treat injured runners with running-related injuries are presented.

Association between Self-Reported Prior Night's Sleep and Single-Task Gait in Healthy, Young Adults: A Study Using Machine Learning

Failure to obtain the recommended 7−9 h of sleep has been associated with injuries in youth and adults. However, most research on the influence of prior night’s sleep and gait has been conducted on older adults and clinical populations. Therefore, the objective of this study was to identify individuals who experience partial sleep deprivation and/or sleep extension the prior night using single task gait. Participants (n = 123, age 24.3 ± 4.0 years; 65% female) agreed to participate in this study. Self-reported sleep duration of the night prior to testing was collected. Gait data was collected with inertial sensors during a 2 min walk test. Group differences (<7 h and >9 h, poor sleepers; 7−9 h, good sleepers) in gait characteristics were assessed using machine learning and a post-hoc ANCOVA. Results indicated a correlation (r = 0.79) between gait parameters and prior night’s sleep. The most accurate machine learning model was a Random Forest Classifier using the top 9 features, which had a mean accuracy of 65.03%. Our findings suggest that good sleepers had more asymmetrical gait patterns and were better at maintaining gait speed than poor sleepers. Further research with larger subject sizes is needed to develop more accurate machine learning models to identify prior night’s sleep using single-task gait.

Comparison of impact accelerations between injury-resistant and recently injured recreational runners

Introduction/Purpose

Previous injury has consistently been shown to be one of the greatest risk factors for running-related injuries (RRIs). Runners returning to participation following injury may still demonstrate injury-related mechanics (e.g. repetitive high impact loading), potentially exposing them to further injuries. The aim of this study was to determine if the magnitude (Peak_accel) and rate of loading (Rate_accel) at the tibia and sacrum differ between runners who have never been injured, those who have acquired injury resistance (runners who have not been injured in the past 2 years) and those who have been recently injured (RRI sustained 3–12 months ago).

Methods

Runners completed an online survey capturing details of their RRI history over the previous 2 years. Never injured runners were matched by sex, quarterly annual mileage and typical training speed to runners who had acquired injury resistance and to runners who had been recently injured. Differences in Peak_accel and Rate_accel of the tibia and sacrum were assessed between the three groups during a treadmill run at a set speed, with consideration for sex.

Results

A total of 147 runners made up the three injury status groups (n: 49 per group). There was a significant main effect of injury status for Peak_accel and Rate_accel at the sacrum, with recently injured runners demonstrating significantly greater Rate_accel than never injured and acquired injury resistant runners. There was also a significant main effect for sex, with females demonstrating greater tibial Peak_accel, sacrum Peak_accel and Rate_accel than males.

Conclusion

Rate_accel at the sacrum distinguishes recently injured runners from never injured runners and runners who may have acquired injury resistance, potentially highlighting poor impact acceleration attenuation in recently injured runners.

What differentiates rearfoot strike runners with low and high vertical load rates?

BACKGROUND

Runners with a rearfoot strike pattern typically show high vertical ground reaction force loading rates (LRs), that are associated with injuries, compared with forefoot strikers. However, some runners with a rearfoot strike pattern run in a way that reduces LRs. Our purpose was to identify differences in running mechanics between rearfoot strike runners with high and low vertical LRs.

METHODS

42 healthy runners, 21 with high (≥ 80.5 BW/s) and 21 with low (≤ 46.3 BW/s) LRs, were included in the current study. Lower extremity kinematic and kinetic data were then collected while participants ran along a 30 m runway. Running mechanics were calculated, including sagittal plane knee stiffness during early stance, the components of knee stiffness (Δ knee flexion and flexion moment), sagittal joint angles at initial contact, as well as cadence. The two LR groups were compared for differences in outcome variables using independent t-tests or Mann Whitney U tests.

FINDINGS

Knee stiffness was significantly lower in the low LR group (p < 0.01, d = 0.87), due to higher knee flexion excursion (p < 0.01, d = 1.38). At initial contact, the low LR group showed lower hip and knee flexion, but greater ankle and foot dorsiflexion (p = 0.01-0.04, d = 0.64-0.93). No differences were found in cadence.

INTERPRETATION

These results provide potential targets, related to gait kinematics and kinetics, for gait retraining aimed at reducing LRs in rearfoot strike runners.

Biomechanical running gait assessments across prevalent adolescent musculoskeletal injuries

BACKGROUND

While there is substantial information available regarding expected biomechanical adaptations associated with adult running-related injuries, less is known about adolescent gait profiles that may influence injury development.

RESEARCH QUESTIONS

Which biomechanical profiles are associated with prevalent musculoskeletal lower extremity injuries among adolescent runners, and how do these profiles compare across injury types and body regions?

METHODS

We conducted a cross-sectional study of 149 injured adolescents (110 F; 39 M) seen at a hospital-affiliated injured runner's clinic between the years 2016-2021. Biomechanical data were obtained from 2-dimensional video analyses and an instrumented treadmill system. Multivariate analyses of variance covarying for gender and body mass index were used to compare continuous biomechanical measures, and Chi-square analyses were used to compare categorical biomechanical variables across injury types and body regions. Spearman's rho correlation analyses were conducted to assess the relationship of significant outcomes.

RESULTS

Patients with bony injuries had significantly higher maximum vertical ground reaction forces (bony: 1.87 body weight [BW] vs. soft tissue: 1.79BW, p = 0.05), and a higher proportion of runners with contralateral pelvic drop at midstance (χ² =5.3, p = 0.02). Maximum vertical ground reaction forces and pelvic drop were significantly yet weakly correlated (ρ = 0.20, p = 0.01). Foot strike patterns differed across injured body regions, with a higher proportion of hip and knee injury patients presenting with forefoot strike patterns (χ² =22.0, p = 0.01).

SIGNIFICANCE

These biomechanical factors may represent risk factors for injuries sustained by young runners. Clinicians may consider assessing these gait adaptations when treating injured adolescent patients.

Intraobserver Assessment of Shear Wave Elastography in Tensor Fasciae Latae and Gluteus Maximus Muscle: The Importance of the Hip Abductor Muscles in Runners Knee Compared to Healthy Controls

Background: Iliotibial band syndrome (ITBS) represents one of the most common running related injuries. The pathophysiology is postulated to be caused by excessive ITB tension, impingement and irritation of soft tissues at the lateral femoral epicondyle. However, direct evidence has yet to be found and the multifactorial etiology is under discussion. The purpose was to evaluate stiffness of ITB, gluteus maximus (GM) and tensor fasciae latae (TFL) muscles using shear wave elastography (SWE). Methods: In 14 patients with clinically verified ITBS and 14 healthy controls, three SWE measurements each of ITB, GM and TFL in both legs was performed to determine measurement reliability and between-group and -leg differences. Results: The mean value of ITB was 12.8 m/s with ICC of 0.76, whereas the values measured in the GM were 3.02 m/s with an ICC of 0.87. No statistically significant difference in controls compared to patients were found (p = 0.62). The mean value of TFL was 5.42 m/s in healthy participants, compared to 3.89 m/s patients with an ICC of 0.98 (p = 0.002). Conclusion: Although SWE showed no difference in ITB stiffness, significant differences for TFL muscle stiffness in runner’s knee was found, suggesting that the hip abductor muscles might play a bigger role in the pathophysiology of ITBS. We aimed to implement baseline values for stiffness assessments and prove reliability for further prospective studies of SWE in runner’s knee.

Prehabilitation for Recreational Runners: Motivators, Influencers, and Barriers to Injury Prevention Strategies for Running-Related Injury

CONTEXT

Injury prevention programs are effective when implemented in team sports, but many recreational runners have less access to such focused interventions or peer support and often seek other sources to learn about injury reduction strategies.

OBJECTIVE

This study aimed to explore runners' motivations in attending a prehabilitation (prehab) for runners workshop, establish their comprehension of prehab, and identify barriers to ongoing engagement with injury prevention.

DESIGN

Qualitative study using focus groups.

PARTICIPANTS AND SETTING

Twenty-two runners participating in prehab for runners workshops took part in one of 4 focus groups, each recorded, transcribed, and analyzed using Grounded Theory to create codes, subthemes, and themes.

RESULTS

Four themes emerged: (1) Participation was influenced by experience of previous injury and worry of cessation of running. As the workshop ran weekly for 4 weeks, opportunity to see someone more than once who was also a physiotherapist influenced participation. (2) Runners welcomed clarification for online exercises and advice suggested for runners. They were surprised by the difficulty of single-leg neuromuscular facilitation exercises and reported benefit from most or all information especially non-exercise-based approaches such as load management, pain monitoring, and running cues. (3) Participants were empowered by a structured, holistic, and evidence-based approach that embraced autonomy for exercise self-selection and progression. Confidence to engage in open discussion was due to small group size. (4) Barriers to prehab were personal responsibility, equipment, time, lack of supervision, and peer influence.

CONCLUSION

A composite approach to strategies for injury risk reduction during prehab, combining progressive exercises with educational resources, can address runners' individual needs. Early discussion of motivational tools on commencement of prehab with guidance from runners on how to incorporate prehab independently into running training is recommended. Providing these tools allows runners to self-identify the approach best suited to their personal running profile at that given time.

Lower Extremity Kinetics and Kinematics in Runners with Patellofemoral Pain: A Retrospective Case–Control Study Using Musculoskeletal Simulation

Patellofemoral pain (PFP) is a common atraumatic knee pathology in runners, with a complex multifactorial aetiology influenced by sex differences. This retrospective case–control study therefore aimed to evaluate lower limb kinetics and kinematics in symptomatic and control male and female runners using musculoskeletal simulation. Lower extremity biomechanics were assessed in 40 runners with PFP (15 females and 25 males) and 40 controls (15 females and 25 males), whilst running at a self-selected velocity. Lower extremity biomechanics were explored using a musculoskeletal simulation approach. Four intergroup comparisons—(1) overall PFP vs. control; (2) male PFP vs. male control; (3) female PFP vs. female control; and (4) male PFP vs. female PFP—were undertaken using linear mixed models. The overall (stress per mile: PFP = 1047.49 and control = 812.93) and female (peak stress: PFP = 13.07 KPa/BW and control = 10.82 KPa/BW) comparisons showed increased patellofemoral joint stress indices in PFP runners. A significantly lower strike index was also shown in PFP runners in the overall (PFP = 17.75% and control = 33.57%) and female analyses (PFP = 15.49% and control = 40.20%), revealing a midfoot strike in control, and a rearfoot pattern in PFP runners. Peak rearfoot eversion and contralateral pelvic drop range of motion (ROM) were shown to be greater in PFP runners in the overall (eversion: PFP = −8.15° and control = −15.09°/pelvic drop ROM: PFP = 3.64° and control = 1.88°), male (eversion: PFP = −8.05° and control = −14.69°/pelvic drop ROM: PFP = 3.16° and control = 1.77°) and female (eversion: PFP = 8.28° and control = −15.75°/pelvic drop ROM: PFP = 3.64° and control = 1.88°) PFP runners, whilst female PFP runners (11.30°) exhibited a significantly larger peak hip adduction compared to PFP males (7.62°). The findings from this investigation highlight biomechanical differences between control and PFP runners, as well as demonstrating distinctions in PFP presentation for many parameters between sexes, highlighting potential risk factors for PFP that may be addressed through focused intervention modalities, and also the need, where appropriate, for sex-specific targeted treatment approaches.

Running-Related Biomechanical Risk Factors for Overuse Injuries in Distance Runners: A Systematic Review Considering Injury Specificity and the Potentials for Future Research

BACKGROUND

Running overuse injuries (ROIs) occur within a complex, partly injury-specific interplay between training loads and extrinsic and intrinsic risk factors. Biomechanical risk factors (BRFs) are related to the individual running style. While BRFs have been reviewed regarding general ROI risk, no systematic review has addressed BRFs for specific ROIs using a standardized methodology.

OBJECTIVE

To identify and evaluate the evidence for the most relevant BRFs for ROIs determined during running and to suggest future research directions.

DESIGN

Systematic review considering prospective and retrospective studies. (PROSPERO_ID: 236,832).

DATA SOURCES

PubMed. Connected Papers. The search was performed in February 2021.

ELIGIBILITY CRITERIA

English language. Studies on participants whose primary sport is running addressing the risk for the seven most common ROIs and at least one kinematic, kinetic (including pressure measurements), or electromyographic BRF. A BRF needed to be identified in at least one prospective or two independent retrospective studies. BRFs needed to be determined during running.

RESULTS

Sixty-six articles fulfilled our eligibility criteria. Levels of evidence for specific ROIs ranged from conflicting to moderate evidence. Running populations and methods applied varied considerably between studies. While some BRFs appeared for several ROIs, most BRFs were specific for a particular ROI. Most BRFs derived from lower-extremity joint kinematics and kinetics were located in the frontal and transverse planes of motion. Further, plantar pressure, vertical ground reaction force loading rate and free moment-related parameters were identified as kinetic BRFs.

CONCLUSION

This study offers a comprehensive overview of BRFs for the most common ROIs, which might serve as a starting point to develop ROI-specific risk profiles of individual runners. We identified limited evidence for most ROI-specific risk factors, highlighting the need for performing further high-quality studies in the future. However, consensus on data collection standards (including the quantification of workload and stress tolerance variables and the reporting of injuries) is warranted.

Injury Prevention, Safe Training Techniques, Rehabilitation, and Return to Sport in Trail Runners

This current concept, narrative review provides the latest integrated evidence of the musculoskeletal injuries involved with trail running and therapeutic strategies to prevent injury and promote safe participation. Running activities that comprise any form of off-road running (trail running, orienteering, short-long distance, different terrain, and climate) are relevant to this review. Literature searches were conducted to 1) identify types and mechanisms of acute and chronic/overuse musculoskeletal injuries in trail runners, 2) injury prevention techniques most relevant to running trails, 3) safe methods of participation and rehabilitation timelines in the sport. The majority of acute and chronic trail running-related musculoskeletal injuries in trail running occur in the lower leg, primarily in the knee and ankle. More than 70% are due to overuse, and ankle sprains are the most common acute injury. Key mechanisms underlying injury and injury progression include inadequate neuromotor control-balance-coordination, running through fatigue, and abnormal kinematics on variable terrain. Complete kinetic chain prehabilitation programs consisting of dynamic flexibility, neuromotor strength and balance, and plyometrics exercise can foster stable, controlled movement on trails. Patient education about early musculoskeletal pain symptoms and training adjustment can help prevent injury from progressing to serious overuse injuries. Real-time adjustments to cadence, step length, and knee flexion on the trail may also mitigate impact-related risk for injury. After injury occurs, rehabilitation will involve similar exercise components, but it will also incorporate rest and active rest based on the type of injury. Multicomponent prehabilitation can help prevent musculoskeletal injuries in trail runners through movement control and fatigue resistance.

Conservative treatment of iliotibial band syndrome in runners: Are we targeting the right goals?

OBJECTIVE

Iliotibial band syndrome (ITBS) is presumably caused by excessive tension in the iliotibial band (ITB) leading to compression and inflammation of tissues lying beneath it. Usually managed conservatively, there is a lack of scientific evidence supporting the treatment recommendations, and high symptom recurrence rates cast doubt on their causal effectiveness. This review discusses the influence of common physiotherapeutic measures on risk factors contributing to tissue compression beneath the ITB.

METHODS

The potential pathogenic factors are presented on the basis of a simple biomechanical model showing the forces acting on the lateral aspect of the knee. Existent literature on the most commonly prescribed physiotherapeutic interventions is critically discussed against the background of this model. Practical recommendations for the optimization of physiotherapy are derived.

RESULTS

According to biomechanical considerations, ITBS may be promoted by anatomical predisposition, joint malalignments, aberrant activation of inserting muscles as well as excessive ITB stiffness. Hip abductor strengthening may correct excessive hip adduction but also increase ITB strain. Intermittent stretching interventions are unlikely to change the ITB's length or mechanical properties. Running retraining is a promising yet understudied intervention.

CONCLUSIONS

High-quality research directly testing different physiotherapeutic treatment approaches in randomized controlled trials is needed.

Novel biomechanical injury risk score demonstrates correlation with lower limb posterior chain injury in 50 elite-level rugby union athletes

Objectives

Lower limb posterior chain injury (PCI) is common among athletic populations, with multifactorial risk factors including age, previous injury, strength measurements, range of motion and training load. Biomechanics are commonly considered in the prevention and rehabilitation of PCI by performance staff. However, there is no documented testing method to assess for associations between biomechanics and PCI. The aim of this study was to investigate whether there is an association between an easily applicable, novel biomechanical assessment tool and PCI.

Methods

Fifty male elite-level rugby union athletes (age 22.83±5.08) participating in the highest tier of England were tested at the start of the 2019 preseason period and PCIs (N=48) were recorded over the 2019/2020 playing season. Participants’ biomechanics were analysed using two-dimensional video analysis against an injury risk score (IRS) system in the performance of the combined movement—prone hip extension and knee flexion. Participants’ biomechanics in carrying out this movement were scored against the 10-point IRS, where the more compensatory movement recorded sees an increase in an individual’s IRS. Participants’ IRS was then compared against the number of PCIs sustained and Spearman’s correlation coefficient was used for statistical analysis.

Results

There is a significant association between IRS and PCI (R=0.542, p<0.001). Linear regression demonstrated that an increase in 1 in IRS was associated with a 35% increase in PCI incidence (R²=0.346).

Conclusion

A significance between the IRS and PCI provides preliminary support for its use as an injury risk assessment tool.

The influence of maturation and sex on pelvis and hip kinematics in youth distance runners

OBJECTIVES

This study aimed to investigate differences in stance phase pelvic and hip running kinematics based on maturation and sex among healthy youth distance runners.

DESIGN

Cross-Sectional.

METHODS

133 uninjured youth distance runners (M = 60, F = 73; age = 13.5 ± 2.7 years) underwent a three-dimensional running analysis on a treadmill at a self-selected speed (2.8 ± 0.6 m·s^-1). Participants were stratified as pre-pubertal, mid-pubertal, or post-pubertal according to the modified Pubertal Maturational Observation Scale. Stance phase pelvis and hip range of motion (RoM) and peak joint positions were extracted. Two-way ANCOVAs (sex, maturation; covariate of running velocity) were used with Bonferroni-Holm method to control for multiple comparisons with a target alpha level of 0.05.

RESULTS

A two-way interaction between sex and maturation was detected (p = 0.009) for frontal plane pelvic obliquity RoM. Post-hoc analysis identified a maturation main effect only among females (p˂0.008). Pelvic obliquity RoM was significantly greater among post-pubertal (p = 0.001) compared to pre-pubertal females. Significant main effects of sex (p = 0.02), and maturation (p = 0.01) were found for hip adduction RoM. Post-hoc analysis indicated a significant increase in hip adduction RoM from pre-pubertal to post-pubertal female runners (p = 0.001). A significant main effect of sex was found for peak hip adduction angle (p = 0.001) with female runners exhibiting greater maximum peak hip adduction compared to males.

CONCLUSIONS

Maturation influences pelvic and hip kinematics greater in female than male runners. Sex differences became more pronounced during later stages of puberty. These differences may correspond to an increased risk for running-related injuries in female runners compared to male runners.

A preliminary analysis of physical therapist agreement regarding the perceived impairments in cases of runners with knee pain

Background: There is a scarcity of evidence describing how physical therapists use data from clinical examinations to inform the treatment of runners with knee pain.Objective: Our purpose was to examine the between physical therapist agreement on the selection of perceived impairments in runners with knee pain.Methods: Twelve physical therapists reviewed two cases of runners with knee pain. The cases included clinical subjective information, objective data, and review of videos of each participant running. Each rater selected up to three perceived impairments (from a list of eight) that each physical therapist would address at the next physical therapy session. Percent agreement was calculated to determine the between rater agreement on each individual perceived impairment selection and Fleiss Kappa was calculated for each unique combination of three perceived impairments per case.Results: Twelve raters with 51 (18-156) months of clinical experience participated. Percent agreement ranged from 8%-100% for both cases for individual impairments. When assessing the unique combination of three impairments selected, inter-rater agreement was less than what is expected due to chance alone (κ = -0.09, p = .92; κ = -0.09, p = .98) for both cases.Conclusion: The 12 physical therapists demonstrated poor to excellent levels of agreement when selecting an individual perceived impairment. Agreement was worse than chance when selecting a combination of three unique impairments.

Kinematic Characteristics of Male Runners With a History of Recurrent Calf Muscle Strain Injury

BACKGROUND

Calf muscle strain injuries are a common running injury affecting male runners and are known to have high reoccurrence rates. Currently, limited evidence exists investigating factors associated with this injury with no previous study investigating the running kinematics of male runners with a history of repeat calf muscle strain injuries.

PURPOSE

To investigate whether male runners with a history of repeat calf muscle strain injury demonstrate differences in stance phase running kinematics when compared to healthy controls.

STUDY DESIGN

Case-control investigation.

LEVEL OF EVIDENCE

3b.

METHODS

Stance phase kinematics were compared between 15 male runners with a history of calf muscle strain injury and 15 male control participants during treadmill running at 3.2m/s. Independent t-tests were used to compare differences in stance phase kinematic parameters between groups and effect sizes were calculated using Cohen's d.

RESULTS

The group with a history of calf muscle strain injury demonstrated a significant 2.1⁰ and 3.1⁰ increase in contralateral pelvic drop and anterior pelvic tilt during mid stance. In addition, this group exhibited longer stance times and a more anterior tilted pelvis, flexed hip and a greater distance between the heel and centre of mass at initial contact. Large effect sizes, greater than 0.8, were observed for all differences. No significant differences were observed for ankle and knee joint kinematics between the groups.

CONCLUSION

This is the first study to identify kinematic characteristics associated with recurrent calf muscle strain injury. While it is not possible to determine causality, the observed kinematic differences may contribute to recurrent nature of this injury. Specifically, it is possible that neuromuscular deficits of the hip and calf muscle complex may lead to increased strain on the calf complex. Rehabilitation interventions which focus on addressing pelvis and hip kinematics may reduce the demands placed upon the calf complex and could prove clinically effective.

Validity of a Rehab and Reconditioning Program Following an Adductor Longus Injury in Professional Soccer

CONTEXT

The high rates of adductor injuries and reinjuries in soccer have suggested that the current rehabilitation programs may be insufficient; therefore, there is a need to create prevention and reconditioning programs to prepare athletes for the specific demands of the sport.

OBJECTIVE

The aim of this study is to validate a rehab and reconditioning program (RRP) for adductor injuries through a panel of experts and determine the effectiveness of this program through its application in professional soccer.

DESIGN

A 20-item RRP was developed, which was validated by a panel of experts anonymously and then applied to 12 injured male professional soccer players.

SETTING

Soccer pitch and indoor gym.

PARTICIPANTS

Eight rehabilitation fitness coaches (age = 33.25 [2.49] y) and 8 academic researchers (age = 38.50 [3.74] y) with PhDs in sports science and/or physiotherapy. The RRP was applied to 12 male professional players (age = 23.75 [4.97] y; height = 180.56 [8.41] cm; mass = 76.89 [3.43] kg) of the Spanish First and Second Division (La Liga).

INTERVENTIONS

The experts validated an indoor and on-field reconditioning program, which was based on strengthening the injured muscle and retraining conditional capacities with the aim of reducing the risk of reinjury.

MAIN OUTCOME MEASURES

Aiken V for each item of the program and number of days taken by the players to return to full team training.

RESULTS

The experts evaluated all items of the program very highly as seen from Aiken V values between 0.77 and 0.94 (range: 0.61-0.98) for all drills, and the return to training was in 13.08 (±1.42) days.

CONCLUSION

This RRP following an injury to the adductor longus was validated by injury experts, and initial results suggested that it could permit a faster return to team training.

The between-day repeatability, standard error of measurement and minimal detectable change for discrete kinematic parameters during treadmill running

BACKGROUND

Kinematic parameters of the trunk, pelvis and lower limbs are frequently associated with both running injuries and performance, and the target of clinical interventions. Currently there is limited evidence reporting the between-day repeatability of discrete kinematic parameters of the trunk, pelvis and lower limbs during treadmill running.

RESEARCH QUESTION

What is the between-day repeatability, standard error of measurement and minimal detectable change of discrete kinematic parameters of the trunk, pelvis and lower limbs during treadmill running?

METHODS

16 healthy participants attended two kinematic data collection sessions two weeks apart. Three-dimensional kinematic data were collected while participants ran on a motorised treadmill at 3.2 m/s. The interclass correlation coefficient, standard error of measurement and minimal detectable change were calculated for discrete kinematic parameters at initial contact, toe off, peak angles and joint excursions during the stance phase of running.

RESULTS

Good to excellent repeatability with low standard error of measurement and minimal detectable change values were observed for sagittal and frontal plane kinematics at initial contact (Range: ICC, 0.829-0.941; SEM, 0.6°- 2.6°; MDC, 1.5°- 7.2) and peak angles during stance (Range: ICC, 0.799 - 0.946; SEM, 0.6°- 2.6°; MDC, 1.7°- 7.1°). Peak transverse plane kinematics of the hip (ICC, 0.783; SEM, 3.2°; MDC, 8.7°) and knee (ICC, 0.739; SEM, 3°; MDC, 8.4°) demonstrated moderate between-day repeatability with large SEM and MDC values. Kinematics at toe off demonstrated the lowest ICC values and largest measurement errors of all parameters (Range: ICC, 0.109 - 0.900; SEM, 0.8°- 5.7°; MDC, 2.5°- 15.7°).

SIGNIFICANCE

This is the first study detailing the measurement error and minimal detectable change for discrete kinematic parameters of the trunk and pelvis during treadmill running. The reported values may provide a useful reference point for future studies investigating between-day differences in running kinematics.

Effect of ACTN3 R577X Genotype on Injury Epidemiology in Elite Endurance Runners

The p.R577X polymorphism (rs1815739) in the ACTN3 gene causes individuals with the ACTN3 XX genotype to be deficient in functional α-actinin-3. Previous investigations have found that XX athletes are more prone to suffer non-contact muscle injuries. This investigation aimed to determine the influence of the ACTN3 R577X polymorphism in the injury epidemiology of elite endurance athletes. Using a cross-sectional experiment, the epidemiology of running-related injuries was recorded for one season in a group of 89 Spanish elite endurance runners. ACTN3 R577X genotype was obtained for each athlete using genomic DNA samples. From the study sample, 42.7% of athletes had the RR genotype, 39.3% had the RX genotype, and 18.0% had the XX genotype. A total of 96 injuries were recorded in 57 athletes. Injury incidence was higher in RR runners (3.2 injuries/1000 h of running) than in RX (2.0 injuries/1000 h) and XX (2.2 injuries/1000 h; p = 0.030) runners. RR runners had a higher proportion of injuries located in the Achilles tendon, RX runners had a higher proportion of injuries located in the knee, and XX runners had a higher proportion of injuries located in the groin (p = 0.025). The ACTN3 genotype did not affect the mode of onset, the severity, or the type of injury. The ACTN3 genotype slightly affected the injury epidemiology of elite endurance athletes with a higher injury rate in RR athletes and differences in injury location. However, elite ACTN3 XX endurance runners were not more prone to muscle-type injuries.

The Effect of Manual Therapy on Lower Extremity Joint Kinematics during Running: A single-subject case study

BACKGROUND

While there is scarcity of current literature to support the effectiveness of muscle energy techniques (MET) with musculoskeletal injuries, the overall impact on gait kinematics necessitates investigation. This case study involved a 48-year-old male runner and aimed to determine the effect of manual therapy, including joint mobilization and MET, on lower extremity (LE) kinematics. The subject had a medical history that included: Achilles tendonitis, low back pain, and iliotibial band syndrome.

METHODS

A clinical exam and Xsens motion capture were performed on the subject prior to treatment and at the conclusion of the 6 weeks of treatment. Motion capture was used to examine bilateral foot contact time, hip transverse plane motion and ankle sagittal plane motion. Pre-treatment and post-treatment ipsilateral and bilateral differences between groups were analyzed.

RESULTS

Changes were noted between ipsilateral and bilateral pre- and post-treatment contact times; right foot sagittal plane joint angle at foot off; left hip transverse plane joint angle at foot contact and foot off, all bilateral pre- and post-treatment hip angles at foot contact and foot off, all bilateral pre- and post-treatment ankle angles at foot contact and foot off.

CONCLUSIONS

Clinical exams paralleled the change in hip external rotation bringing the hips to a more neutral position. In addition, the final clinical exam noted a decrease in subtalar eversion bilaterally, which may relate to the improved pelvic symmetry and biomechanical compensation pattern. Clinically, these findings may coincide with improving proximal lumbopelvic symmetry assisting with normalizing distal mobility by using manual therapy.

Comparison of Transverse Plane Tibial and Frontal Plane Rearfoot Motion and Movement Coordination Between Runners With Medial Tibial Stress Syndrome and Healthy Controls

Medial tibial stress syndrome (MTSS) is a common running-related injury. Alterations in movement patterns and movement coordination patterns have been linked to the development of overuse injuries. The aim of this study was to compare transverse plane tibial and frontal plane rearfoot motion and the coordination of these movements between runners with MTSS and healthy controls. A total of 10 recreational runners with MTSS and 10 healthy controls ran at 11 km/h on a treadmill. A 3-camera motion analysis system operating at 200 Hz was used to calculate tibia and rearfoot motion. Stance phase motion patterns were compared between groups using multivariate analysis, specifically, Hotelling T2 test with statistical parametric mapping. A modified vector coding technique was used to classify the coordination of transverse plane tibial and frontal plane rearfoot motion. The frequency of each coordination pattern displayed by each group was compared using independent samples t tests. Individuals with MTSS displayed significantly (P = .037, d = 1.00) more antiphase coordination (tibial internal rotation with rearfoot inversion) despite no significant (P > .05) differences in stance phase kinematics. The increased antiphase movement may increase the torsional stress placed upon the medial aspect of the tibia, contributing to the development of MTSS.

Wearable Sensors Detect Differences between the Sexes in Lower Limb Electromyographic Activity and Pelvis 3D Kinematics during Running

Each year, 50% of runners suffer from injuries. Consequently, more studies are being published about running biomechanics; these studies identify factors that can help prevent injuries. Scientific evidence suggests that recreational runners should use personalized biomechanical training plans, not only to improve their performance, but also to prevent injuries caused by the inability of amateur athletes to tolerate increased loads, and/or because of poor form. This study provides an overview of the different normative patterns of lower limb muscle activation and articular ranges of the pelvis during running, at self-selected speeds, in men and women.

METHODS

38 healthy runners aged 18 to 49 years were included in this work. We examined eight muscles by applying two wearable superficial electromyography sensors and an inertial sensor for three-dimensional (3D) pelvis kinematics.

RESULTS

the largest differences were obtained for gluteus maximus activation in the first double float phase (p = 0.013) and second stance phase (p = 0.003), as well as in the gluteus medius in the second stance phase (p = 0.028). In both cases, the activation distribution was more homogeneous in men and presented significantly lower values than those obtained for women. In addition, there was a significantly higher percentage of total vastus medialis activation in women throughout the running cycle with the median (25th-75th percentile) for women being 12.50% (9.25-14) and 10% (9-12) for men. Women also had a greater range of pelvis rotation during running at self-selected speeds (p = 0.011).

CONCLUSIONS

understanding the differences between men and women, in terms of muscle activation and pelvic kinematic values, could be especially useful to allow health professionals detect athletes who may be at risk of injury.