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Differences in Knee and Hip Adduction and Hip Muscle Activation in Runners With and Without Iliotibial Band Syndrome

PainSci » bibliography » Baker et al 2018
Tags: biomechanics, etiology, knee, IT band pain, pro, leg, limbs, pain problems, overuse injury, injury, running, exercise, self-treatment, treatment, tendinosis

One article on PainSci cites Baker 2018: The Complete Guide to IT Band Syndrome

PainSci commentary on Baker 2018: ?This page is one of thousands in the bibliography. It is not a general article: it is focused on a single scientific paper, and it may provide only just enough context for the summary to make sense. Links to other papers and more general information are provided wherever possible.

This tiny study identified a tiny difference in the activation of the tensor fascia latae muscle, and a tiny difference in adduction, in runners with IT band syndrome — all of which has only a tiny chance of having any clinical or even etiological meaning in the absence of more and better data, from research actually designed to explore the topic. It’s probably just a bit of noise in the data. Even if the signal was clearer, good luck interpreting it.

It’s not a bad study or paper, but it is trivial. To the authors’ credit, they wrote: “We advise caution using these findings to support treatments intended to modify tensor fasciae latae activation…” It they hadn’t said it, I would have!

~ Paul Ingraham

Common issues and characteristics relevant to this paper: ?Scientific papers have many common characteristics, flaws, and limitations, and many of these are rarely or never acknowledged in the paper itself, or even by other reviewers. I have reviewed thousands of papers, and described many of these issues literally hundreds of times. Eventually I got sick of repeating myself, and so now I just refer to a list common characteristics, especially flaws. Not every single one of them applies perfectly to every paper, but if something is listed here, it is relevant in some way. Note that in the case of reviews, the issue may apply to the science being reviewed, and not the review itself.

  1. Risk of inadequate statistical power.
  2. A junky or trivial little study that was probably published more to pad someone’s resumé than to actually answer a research question. We are drowning in studies like this, which mostly just muddy the waters with more inadequate data.

original abstract Abstracts here may not perfectly match originals, for a variety of technical and practical reasons. Some abstacts are truncated for my purposes here, if they are particularly long-winded and unhelpful. I occasionally add clarifying notes. And I make some minor corrections.

BACKGROUND: Iliotibial band syndrome (itbs) has been associated with altered hip and knee kinematics in runners. Previous studies have recommended further research on neuromuscular factors at the hip. The frontal plane hip muscles have been a strong focus in strength comparison but not for electromyography investigation.

OBJECTIVE: To compare hip surface electromyography, and frontal plane hip and knee kinematics, in runners with and without ITBS.

DESIGN: Observational cross-sectional study.

SETTING: Biomechanics research laboratory within a university.

PARTICIPANTS: Thirty subjects were recruited consisting of 15 injured runners with ITBS and 15 gender-, age-, and body mass index-matched controls. In each group, 8 were male runners and 7 were female runners. Inclusion criteria for the injured group were pain within 2 months related to ITBS and a positive Noble compression test. Participants were excluded if they reported other lower extremity diagnoses within the last year or active lower extremity or low back pain not related to ITBS. Controls were excluded if they reported a history of ITBS. Convenience sampling was used based on referrals from local running clinics and orthopedic clinics.

METHODS: Three-dimensional motion capture was performed with 10 high-speed cameras synchronized with wireless surface electromyography during a 30-minute run. The first data point was at 3 minutes, using a constant speed of 2.74 meters per second. A second data point was at 30 minutes, using a self-selected pace by the participant to allow for a challenging run until completion at 30 minutes.

MAIN OUTCOME MEASUREMENTS: Motion capture was reported as peak kinematic values from heel strike to peak knee flexion for hip adduction and knee adduction. Surface electromyography was reported as a percentage of maximal voluntary contraction for the gluteus maximus, gluteus medius and tensor fascia latae muscles.

RESULTS: Injured runners demonstrated increased knee adduction compared with control runners at 30 minutes (P = .002, control = -1.48°, injured = 3.74°). Tensor fasciae latae muscle activation in injured runners was increased compared with control runners at 3 minutes (P = .017, control = 7% maximal voluntary isometric contraction, injured = 11% maximal voluntary isometric contraction).

CONCLUSION: The results of this study suggest that lateral knee pain in runners localized to the distal iliotibial band is associated with increased knee adduction at 30 minutes. Increased tensor fasciae latae muscle activation at 3 minutes is noted, but more investigation is needed to better understand the clinical meaning. «Understatement!» These findings are consistent with but not conclusive evidence supporting the theory that neuromuscular factors of the hip muscles may contribute to increased knee adduction in runners with ITBS. We advise caution using these findings to support treatments intended to modify tensor fasciae latae activation, given the small differences of 4% in muscle activation. Increased knee adduction in runners at 30 minutes was over 5° and beyond the minimal detectable difference. Additional research is needed to confirm whether the degree of knee adduction changes earlier versus later in a run and whether fatigue is a clinically relevant factor.


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This page is part of the PainScience BIBLIOGRAPHY, which contains plain language summaries of thousands of scientific papers & others sources. It’s like a highly specialized blog. A few highlights: