Frontal plane kinematics predict three-dimensional hip adduction during running

Pre-pubertal runners demonstrate greater variability in running kinematics than post-pubertal runners

BACKGROUND

Adolescents undergo a period of motor incoordination during puberty characterized by high movement variability. It is unknown if differences in running kinematics variability exist among adolescent long-distance runners.

RESEARCH QUESTION

Is kinematic variability different among male and female adolescent long-distance runners of different stages of physical maturation?

METHODS

We enrolled 114 adolescent long-distance runners (ages 8-19, F = 55, M = 59) in this secondary analysis of a larger cross-sectional study. Participants completed a three-dimensional overground running analysis at a comfortable self-selected speed. Peak frontal, sagittal, and transverse plane hip, knee, and ankle/shoe joint angles from the right leg were identified during stance phase for at least five trials. Variability in running kinematics was quantified as the standard deviation of the peak joint angles among the running trials for each participant. Participants were stratified by sex and stage of physical maturation (pre-, mid-, post-pubertal) and two-way ANOVAs compared between-subjects variability among groups (p ≤ .05).

RESULTS

Significant sex by maturation interactions were observed for hip external rotation and ankle external rotation variability. Sex differences were observed for hip internal rotation, with males demonstrating greater variability, and ankle internal rotation, with females demonstrating greater variability. Pre-pubertal runners demonstrated significantly greater variability than mid-pubertal runners for hip flexion, and greater variability than post-pubertal runners for hip flexion, hip adduction, hip internal rotation, and knee flexion.

SIGNIFICANCE

Pre-pubertal adolescent long-distance runners demonstrate greater stance phase variability in running kinematics than post-pubertal adolescent long-distance runners, while adolescent males and females demonstrate similar variability. Anthropometric and neuromuscular changes that occur during puberty likely influence running patterns and may contribute to more consistent kinematic patterns for post-pubertal runners.

Knee Valgus Versus Knee Abduction Angle: Comparative Analysis of Medial Knee Collapse Definitions in Female Athletes

The knee valgus angle (KVA) is heavily researched as it has been shown to correlate to anterior cruciate ligament (ACL) injuries when measured during jumping activities. Many different methods of KVA calculation are often treated as equivalent. The purpose of this study is to elucidate differences between these commonly used angles within and across activities to determine if they can indeed properly be treated as equivalent. The kinematics of 23 female athletes, D1 soccer, D1 basketball, and club soccer (height = 171.2 ± 88.9 cm, weight = 66.3 ± 8.6 kg, age = 19.8 ± 1.9 years), was analyzed using a motion capture system during activities related to their sport and daily living. The abduction KVA, measured using body fixed axes, only correlated to the two-dimensional (2D) global reference frame angle (KVA 2G) in three of the six activities (walking, squatting, and walking down stairs), and one out of six in the three-dimensional (3D) measurements (jogging). This suggests that the abduction KVA does not always relate to other versions of KVA. The KVA with reference to the pelvis coordinate system (KVA 2P) correlated to the KVA 2G in six out of six activities (r = 0.734  ±  0.037, P << 0.001) suggesting the pelvis can be utilized as a reference plane during rotating tasks, such as run-to-cut, when a fixed global system is less meaningful. Not all measures of KVA are equivalent and should be considered individually. A thorough understanding of the equivalence or nonequivalence of various measures of KVA is essential in understanding ACL injury risk.

Extended Version of a Test Battery for Visual Assessment of Postural Orientation Errors: Face Validity, Internal Consistency, and Reliability

OBJECTIVE

Undesirable postural orientation may be a risk factor for a second anterior cruciate ligament (ACL) injury. The purpose of this study was to evaluate face validity, internal consistency, and interrater reliability of an extended version of a previous test battery for visual assessment of postural orientation errors (POEs) in patients during the late phase of rehabilitation following ACL reconstruction (ACLR) (ie, when they have initiated jumping exercises).

METHODS

This study used a cross-sectional design. Fifty-three patients (45% women) in the late phase of ACLR rehabilitation performed 5 functional tasks of varying difficulty. POEs of the lower extremity and trunk were visually assessed from video and scored on a scale from 0 (good) to 2 (poor).

RESULTS

The side-hop and 2 new POEs (femur medial to shank, femoral valgus) were added to the test battery after expert focus group discussions. Internal consistency was calculated for all tasks (α = .712-.823). Interrater reliability showed fair to substantial agreement for femur medial to shank and femoral valgus during all tasks (K = 0.31-0.815) and almost perfect agreement for side-hop (intraclass correlation coefficient = 0.88).

CONCLUSIONS

The good internal consistency and reliability after adding side-hop, femur medial to shank, and femoral valgus suggests that this test battery is a suitable tool to quantify postural orientation throughout ACLR rehabilitation.

IMPACT

This test battery for visual assessment of POEs was evaluated in a heterogeneous group of patients in different phases of ACLR battery and can be used in clinical practice to measure POEs in patients with ACLR, including in the late phase of rehabilitation to return to sport. This study encourages research on more demanding tasks and additional POEs to cover the entire rehabilitation period after ACL injury or reconstruction.

Effect of neuromuscular training augmented with knee valgus control instructions on lower limb biomechanics of male runners

OBJECTIVE

To examine if combining neuromuscular training (NMT) with knee valgus control instructions (VCIs) can affect lower limb biomechanics and injury incidence in male novice runners and assess over 1-year follow-up.

DESIGN

Controlled laboratory Study.

SETTING

University research laboratory.

PARTICIPANTS

60 male novice runners randomly assigned into NMT (n = 20), NMT plus VCIs (n = 20), and sham (n = 20).

MAIN OUTCOME MEASURES

Kinematic and kinetic were measured at pre- and post-test and 1-year follow-up. Injury incidence assessed at pre-test and 1-year follow up.

RESULTS

There were significant between-group differences in kinetics after 6 weeks in NMT plus VCIs group. No significant differences were observed between NMT and NMT plus VCIs in kinematic variables. No significant change was seen in the sham in all variables. At 1-year follow-up, the minimal changes were seen in kinetic variables. Reduction reported running-related injuries were 31.58% in the NMT alone group, 65.52% in NMT plus VCIs group. In sham, it increased to 13.46%.

CONCLUSIONS

NMT plus VCIs was effective to reduce kinetics and improve kinematics in novice runners. Also, it could reduce injury incidence. This protocol may be an option for both athletic trainers and coaches for preventing of lower limbs' injury in male runners.

Do alterations in muscle strength, flexibility, range of motion, and alignment predict lower extremity injury in runners: a systematic review

Background

Injury is common in running and seen to impact up to 94% of recreational runners. Clinicians often use alterations from normal musculoskeletal clinical assessments to assess for risk of injury, but it is unclear if these assessments are associated with future injury.

Objectives

To identify alterations in muscle strength, flexibility, range of motion, and alignment that may predict lower extremity injury in runners.

Methods

Articles were selected following a comprehensive search of PubMed, Embase, CINAHL, and SPORTDiscus from database inception to May 2018. Included articles were prospective cohort studies, which specifically analyzed musculoskeletal impairments associated with future running-related injury. Two authors extracted study data, assessed the methodological quality of each study using the Critical Appraisal Tool and assessed the overall quality using the GRADE approach.

Results

Seven articles met the inclusion criteria. There was very low quality of evidence for the 7 identified clinical assessment alteration categories. Strong hip abductors were significantly associated with running-related injury in one study. Increased hip external-to-internal rotation strength and decreased hip internal range of motion were protective for running injury, each in one study. Decreased navicular drop in females had a protective effect for running-related injury in one study.

Conclusions

Due to very low quality of evidence for each assessment, confounders present within the studies, a limited number of studies, different measurement methods among studies, measurement variability within clinical assessments, inconsistent definitions of injury and runner, different statistical modeling, and study bias, caution is suggested in interpreting these results.