Weight-Acceptance Phase of Single- Leg Jump Landing Kristin Morgan - - PowerPoint PPT Presentation

▶

Oct 23, 2022 550 likes •785 views

Muscle Force Estimates During The Weight-Acceptance Phase of Single- Leg Jump Landing Kristin Morgan BME 599 4/26/12 Motivation Over 200,000 anterior cruciate ligament (ACL) injuries $1.5 billion annually 78% are non-contact

SLIDE 1

Muscle Force Estimates During The Weight-Acceptance Phase of Single- Leg Jump Landing

Kristin Morgan BME 599 4/26/12

SLIDE 2

Motivation

Over 200,000 anterior

cruciate ligament (ACL) injuries

$1.5 billion annually
78% are non-contact

injury

22% result from jump

landing

SLIDE 3

Background

Role of the Anterior Cruciate Ligament (ACL)

One of four ligaments in the

knee (ACL, PCL, MCL, LCL)

Restricts anterior translation
f the tibia
Limits rotational movement
Stabilizer

http://www.aidmyknee.com/anterior-cruciate-ligament.php

SLIDE 4

Background

Characteristics of ACL Injury

Small Knee Flexion Angle
Elevated Knee Valgus

Moment

Anterior Translation of

the Tibia

http://www.youcanbefit.com/ACL.html

SLIDE 5

Research Question

Kinematics
Kinetics
Surface electromyography

(sEMG)

Muscles support the knee

and could potentially reduce ACL injury risk

http://www.emg-eeg.com/emg/rutin-emg

What are the individual muscle force contributions to single-leg jump landing?

SLIDE 6

Experimental Design

58 participants conducted a

SLJL procedure

– Jumped & Landed with preferred leg – Ball was perturbed during flight phase

Whole body kinematics &

GRF were measured

sEMG collected for six

muscles

10 participant trials were

randomly chosen for further analysis

1 2 4 3 5 7 6 8 9

SLIDE 7

Experimental Design

SLIDE 8

Weight Acceptance Phase

Series of images for a subject-specific simulation during the weight acceptance

f single-leg jump landing using a

musculoskeletal model.

1 2 3 4 5 6

SLIDE 9

3D Musculoskeletal Model

q6 q7 q8 q3 q4 q5 q9 q11 q10 q12 q2 q1 q13

Delp et al. (1990, 2007), IEEE Trans Biomed Eng

92 muscle-tendon actuators
23 degrees of freedom
Scaled to patient data

2 male Australian football players Height: 1.89m Mass: 86kg

SLIDE 10

Create Subject-Specific Simulation

Scaling

Generic musculoskeletal model was scaled to subjects’ mass properties and segment dimensions obtained from experimental exams and marker data

Inverse Kinematics (IK)

Derive joint angles from the experimental kinematic data

Residual Reduction Analysis (RRA)

Create dynamically consistent simulations with the experimentally recorded ground reaction forces

Computed Muscle Control (CMC)

Used to estimate muscle excitations and muscle forces

SLIDE 11

Computed Muscle Control

SLIDE 12

Computed Muscle Control Results

SLIDE 13

Computed Muscle Control Files

Actuator Control Constraints Task Weightings

SLIDE 14

Computed Muscle Control Results

SLIDE 15

Validation Check

Evaluate IK and CMC Kinematics

1.4 1.44 1.48 30 60

Time (s) Knee Flexion (°)

Inverse Kinematics CMC Kinematics

SLIDE 16

Validation Check

Analyze CMC Residuals

SLIDE 17

Validation Check

Compare sEMG and CMC Excitations

SLIDE 18

Computed Muscle Control Results

SLIDE 19

Computed Muscle Control Results

SLIDE 20

Discussion

Largest muscle force estimates in

decreasing order were the quadriceps and gastrocnemius followed by the hamstrings

Primary motor control task during

landing of producing a support moment capable of maintaining the center of mass in an upright position

The gastrocnemius plays a much

larger role than the hamstrings muscles in dynamic knee movements during single-leg landing.

Further analysis is necessary to

determine whether muscles may be selectively recruited based on moment arms to support the knee from externally valgus knee loading.

SLIDE 21

Future Work

Additional Subjects Induced Acceleration

SLIDE 22