# Muscle Geometry and its Influence on Function in Patients with Developmental Dysplasia of the Hip

> **NIH NIH K01** · WASHINGTON UNIVERSITY · 2020 · $110,845

## Abstract

PROJECT SUMMARY
 Developmental dysplasia of the hip (DDH) dramatically increases risk for early development of hip
osteoarthritis (OA) in adolescents and young adults. In cases of DDH, abnormal development of the
acetabulum (hip socket) and femur alter loading inside the joint, which can lead to painful acetabular labrum
tears and articular cartilage lesions. Without correction, this joint damage progresses to OA and may require
total joint replacement. Pain and physical limitation are common symptoms in patients with DDH. However, the
presentation, intensity and combination of symptoms do not always correspond with radiographic signs of bony
abnormalities or soft-tissue damage. Factors beyond bony structure, such as muscle function, likely contribute
to symptom onset and altered joint loading, but the role of muscle in DDH pathomechanics is not well
understood. This project will be the first to rigorously investigate the bone-muscle relationship as a factor in
pathomechanics and symptomatology in patients with DDH. In Aim 1, we will use magnetic resonance imaging
(MRI) and musculoskeletal models to compare hip muscle volumes, 3D muscle moment arms, and muscle
strength between patients with DDH and control subjects. Aim 1 will provide the first 3D analyses of muscle
geometry and moment arms in patients with DDH, and may elucidate relationships among muscle alterations,
the severity of bony abnormalities, and muscle weakness. In Aim 2, we will use 3D motion capture to quantify
hip movement and loading during activities of increasing biomechanical demand. Analyzing a range of
activities that are common for our patients with DDH can identify mechanical distinctions between patients and
control subjects that contribute to symptoms and joint damage. In Aim 3, we will identify translational
relationships between our laboratory measures and clinical measures of patient reported outcomes (PROs).
Identifying such relationships can establish novel links between important realms of patient evaluation –
laboratory measurement and clinical research. Ultimately, we seek coordinated surgical and nonsurgical
approaches that optimize joint loading and balance muscle use to improve treatment and delay OA for patients
with DDH. Thus, in an exploratory Aim 4, we will compare bone-muscle geometry, strength, hip mechanics,
and PROs one year after hip preservation surgery to pre-surgical values and determine the variables predictive
of post-surgical outcomes. This proposal builds on the candidate's prior work in intra-articular mechanics and
bone morphology and provides new training in MRI, strength testing, modeling, and clinical research with
patients with hip disorders. The mentor team consists of physical therapists, orthopedic surgeons and
bioengineers who are experts in muscle structure-function, MRI, OA development, and clinical intervention for
DDH. Together, the results from this proposal will provide preliminary data for an R01 focused on key factors
that aff...

## Key facts

- **NIH application ID:** 9888331
- **Project number:** 5K01AR072072-03
- **Recipient organization:** WASHINGTON UNIVERSITY
- **Principal Investigator:** Michael D Harris
- **Activity code:** K01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $110,845
- **Award type:** 5
- **Project period:** 2018-04-01 → 2023-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9888331

## Citation

> US National Institutes of Health, RePORTER application 9888331, Muscle Geometry and its Influence on Function in Patients with Developmental Dysplasia of the Hip (5K01AR072072-03). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9888331. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*