Anchoring and Postural Stability

Anchoring and Its Effects on Postural Stability

This study will compare standing balance in adults ages 18 to 50 during normal standing, inward anchoring, and outward anchoring. Anchoring involves standing with the feet wider than shoulder width and trying to pull the legs together or push them apart without moving the feet. Participants will complete all three conditions in a randomly assigned order. A researcher will use a handheld force-measuring instrument at six points on the pelvis to measure how much pressure participants can resist before a foot lifts from the floor. Participants will also rate how stable they feel after each anchoring condition. The first 18 participants will repeat assessments to evaluate measurement consistency. Participation is expected to last 60 minutes, or 90 minutes for those completing repeat assessments.

Study Overview

• Status: Recruiting
• Conditions: Healthy Adult Participants
• Intervention / Treatment: Other: Normal Stance; Other: Inward Anchoring; Other: Outward Anchoring

Detailed Description

The study will enroll 72 adults from the University of Central Florida community. Participants will be randomized with equal probability to one of six counterbalanced orders of normal stance, inward anchoring, and outward anchoring. Every participant will complete all three conditions.

Inward anchoring involves attempting to draw the legs toward one another without moving the feet. Outward anchoring involves attempting to press the legs away from one another without moving the feet. Both anchoring conditions use a stance wider than shoulder width. Participants will wear their usual athletic footwear.

The same tester will apply a microFET2 handheld dynamometer at the right and left anterior superior iliac spines, iliac crests, and posterior superior iliac spines. Applied pressure will increase until the sole of the foot closest to the tester leaves the floor, at which point force will be recorded in newtons. Each site will be tested three times in each stance. Rest periods will be one minute between sets within a stance and two minutes between stances. Instructions for the next stance will be given during the final minute of the between-stance rest period.

After each anchoring condition, participants will rate perceived stability. The first 18 participants will complete additional repeat assessments for intrarater reliability analysis. The protocol plans repeated-measures analyses for stance/order comparisons and intraclass correlation coefficients for reliability.

• Study Type: Interventional
• Enrollment (Estimated): 72
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: William J Hanney, PhD; Phone Number: 4078230217; Email: william.j.hanney@ucf.edu

Study Locations

• United States
  • Florida
    • Orlando, Florida, United States, 32816
      • Recruiting
      • University of Central Florida Spine and Mobility Lab
      • Contact: William J Hanney, PhD; Phone Number: 4078230217; Email: william.j.hanney@ucf.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 50 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Adults aged 18-50 years.
• Able to provide informed consent and independently read, write, and communicate in English.

Exclusion Criteria:

• History of neurological or vestibular conditions affecting balance, such as stroke, Parkinson's disease, multiple sclerosis, or vertigo, or uncorrected/inadequately corrected visual deficits affecting postural control.
• Lower-extremity or spinal injury, orthopedic surgery, or a musculoskeletal condition within the past 6-12 months that may affect balance, force production, or safe participation.
• Current pain or dysfunction limiting safe standing or weight-bearing tasks.
• Use of medications that may affect balance, coordination, or muscle performance, such as muscle relaxants, opioids, or sedatives.
• A cardiovascular or systemic condition that makes participation unsafe, such as uncontrolled hypertension, dizziness, or syncope, or inability to stand independently for the duration of testing.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Screening
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

6

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Normal Stance → Inward Anchoring → Outward Anchoring; Participants complete normal stance, then inward anchoring, then outward anchoring. The same force assessments are performed in each condition, with two minutes of rest between conditions.	Other: Normal Stance; Participants stand normally while the tester performs the protocol's pelvic force assessments. This condition provides the within-participant comparison for the two anchoring techniques; Other: Inward Anchoring; Participants stand upright with their feet wider than shoulder width and attempt to pull their legs toward each other without moving the feet. They maintain the position during the pelvic force assessments.; Other: Outward Anchoring; Participants stand upright with their feet wider than shoulder width and attempt to push their legs away from each other without moving the feet. They maintain the position during the pelvic force assessments.
Experimental: Normal Stance → Outward Anchoring → Inward Anchoring; Participants complete normal stance, then outward anchoring, then inward anchoring. The same force assessments are performed in each condition, with two minutes of rest between conditions.	Other: Normal Stance; Participants stand normally while the tester performs the protocol's pelvic force assessments. This condition provides the within-participant comparison for the two anchoring techniques; Other: Inward Anchoring; Participants stand upright with their feet wider than shoulder width and attempt to pull their legs toward each other without moving the feet. They maintain the position during the pelvic force assessments.; Other: Outward Anchoring; Participants stand upright with their feet wider than shoulder width and attempt to push their legs away from each other without moving the feet. They maintain the position during the pelvic force assessments.
Experimental: Outward Anchoring → Normal Stance → Inward Anchoring; Participants complete outward anchoring, then normal stance, then inward anchoring. The same force assessments are performed in each condition, with two minutes of rest between conditions.	Other: Normal Stance; Participants stand normally while the tester performs the protocol's pelvic force assessments. This condition provides the within-participant comparison for the two anchoring techniques; Other: Inward Anchoring; Participants stand upright with their feet wider than shoulder width and attempt to pull their legs toward each other without moving the feet. They maintain the position during the pelvic force assessments.; Other: Outward Anchoring; Participants stand upright with their feet wider than shoulder width and attempt to push their legs away from each other without moving the feet. They maintain the position during the pelvic force assessments.
Experimental: Outward Anchoring → Inward Anchoring → Normal Stance; Participants complete outward anchoring, then inward anchoring, then normal stance. The same force assessments are performed in each condition, with two minutes of rest between conditions.	Other: Normal Stance; Participants stand normally while the tester performs the protocol's pelvic force assessments. This condition provides the within-participant comparison for the two anchoring techniques; Other: Inward Anchoring; Participants stand upright with their feet wider than shoulder width and attempt to pull their legs toward each other without moving the feet. They maintain the position during the pelvic force assessments.; Other: Outward Anchoring; Participants stand upright with their feet wider than shoulder width and attempt to push their legs away from each other without moving the feet. They maintain the position during the pelvic force assessments.
Experimental: Inward Anchoring → Normal Stance → Outward Anchoring; Participants complete inward anchoring, then normal stance, then outward anchoring. The same force assessments are performed in each condition, with two minutes of rest between conditions.	Other: Normal Stance; Participants stand normally while the tester performs the protocol's pelvic force assessments. This condition provides the within-participant comparison for the two anchoring techniques; Other: Inward Anchoring; Participants stand upright with their feet wider than shoulder width and attempt to pull their legs toward each other without moving the feet. They maintain the position during the pelvic force assessments.; Other: Outward Anchoring; Participants stand upright with their feet wider than shoulder width and attempt to push their legs away from each other without moving the feet. They maintain the position during the pelvic force assessments.
Experimental: Inward Anchoring → Outward Anchoring → Normal Stance; Participants complete inward anchoring, then outward anchoring, then normal stance. The same force assessments are performed in each condition, with two minutes of rest between conditions.	Other: Normal Stance; Participants stand normally while the tester performs the protocol's pelvic force assessments. This condition provides the within-participant comparison for the two anchoring techniques; Other: Inward Anchoring; Participants stand upright with their feet wider than shoulder width and attempt to pull their legs toward each other without moving the feet. They maintain the position during the pelvic force assessments.; Other: Outward Anchoring; Participants stand upright with their feet wider than shoulder width and attempt to push their legs away from each other without moving the feet. They maintain the position during the pelvic force assessments.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean Break-Point Force at the Right Anterior Superior Iliac Spine	A microFET2 handheld dynamometer is applied at the right anterior superior iliac spine during normal stance, inward anchoring, and outward anchoring. Force in newtons is recorded when the sole of the foot closest to the tester leaves the floor. Three readings are collected per stance	Day 1
Mean Break-Point Force at the Left Anterior Superior Iliac Spine	A microFET2 handheld dynamometer is applied at the left anterior superior iliac spine during normal stance, inward anchoring, and outward anchoring. Force in newtons is recorded when the sole of the foot closest to the tester leaves the floor. Three readings are collected per stance.	Day 1
Mean Break-Point Force at the Right Iliac Crest	A microFET2 handheld dynamometer is applied at the right iliac crest during normal stance, inward anchoring, and outward anchoring. Force in newtons is recorded when the sole of the foot closest to the tester leaves the floor. Three readings are collected per stance	Day 1
Mean Break-Point Force at the Left Iliac Crest	A microFET2 handheld dynamometer is applied at the left iliac crest during normal stance, inward anchoring, and outward anchoring. Force in newtons is recorded when the sole of the foot closest to the tester leaves the floor. Three readings are collected per stance.	Day 1
Mean Break-Point Force at the Right Posterior Superior Iliac Spine	A microFET2 handheld dynamometer is applied at the right posterior superior iliac spine during normal stance, inward anchoring, and outward anchoring. Force in newtons is recorded when the sole of the foot closest to the tester leaves the floor. Three readings are collected per stance.	Day 1
Mean Break-Point Force at the Left Posterior Superior Iliac Spine	A microFET2 handheld dynamometer is applied at the left posterior superior iliac spine during normal stance, inward anchoring, and outward anchoring. Force in newtons is recorded when the sole of the foot closest to the tester leaves the floor. Three readings are collected per stance.	Day 1
Perceived Stability Rating After Inward Anchoring	After inward anchoring, participants answer how stable they felt during that stance. Ratings range from 0 (not at all stable) to 10 (completely stable); 5 means neutral, or the same stability as normal standing. Higher scores indicate greater perceived stability.	Day 1
Perceived Stability Rating After Outward Anchoring	After outward anchoring, participants answer how stable they felt during that stance. Ratings range from 0 (not at all stable) to 10 (completely stable); 5 means neutral, or the same stability as normal standing. Higher scores indicate greater perceived stability	Day 1

Collaborators and Investigators

• Sponsor: University of Central Florida
• Investigators: Principal Investigator: William J Hanney, PhD, University of Central Florida

Publications and helpful links

General Publications

• Nakagawa HB, Ferraresi JR, Prata MG, Scheicher ME. Postural balance and functional independence of elderly people according to gender and age: cross-sectional study. Sao Paulo Med J. 2017 May-Jun;135(3):260-265. doi: 10.1590/1516-3180.2016.0325280217.
• Johansson J, Nordstrom A, Gustafson Y, Westling G, Nordstrom P. Increased postural sway during quiet stance as a risk factor for prospective falls in community-dwelling elderly individuals. Age Ageing. 2017 Nov 1;46(6):964-970. doi: 10.1093/ageing/afx083.
• Thomas DT, R S, Prabhakar AJ, Dineshbhai PV, Eapen C. Hip abductor strengthening in patients diagnosed with knee osteoarthritis - a systematic review and meta-analysis. BMC Musculoskelet Disord. 2022 Jun 29;23(1):622. doi: 10.1186/s12891-022-05557-6.
• Zemkova E, Zapletalova L. The Role of Neuromuscular Control of Postural and Core Stability in Functional Movement and Athlete Performance. Front Physiol. 2022 Feb 24;13:796097. doi: 10.3389/fphys.2022.796097. eCollection 2022.
• Inacio M, Creath R, Rogers MW. Low-dose hip abductor-adductor power training improves neuromechanical weight-transfer control during lateral balance recovery in older adults. Clin Biomech (Bristol). 2018 Dec;60:127-133. doi: 10.1016/j.clinbiomech.2018.10.018. Epub 2018 Oct 13.
• Iwamoto K, Yoshio M, Takata Y, Kozuka N. Reliability and validity of standing balance assessment index using a hand-held dynamometer in stroke patients. J Phys Ther Sci. 2016 Nov;28(11):3158-3161. doi: 10.1589/jpts.28.3158. Epub 2016 Nov 29.
• Hyun SJ, Lee J, Lee BH. The Effects of Sit-to-Stand Training Combined with Real-Time Visual Feedback on Strength, Balance, Gait Ability, and Quality of Life in Patients with Stroke: A Randomized Controlled Trial. Int J Environ Res Public Health. 2021 Nov 21;18(22):12229. doi: 10.3390/ijerph182212229.
• Delmore RJ, Laudner KG, Torry MR. Adductor longus activation during common hip exercises. J Sport Rehabil. 2014 May;23(2):79-87. doi: 10.1123/jsr.2012-0046. Epub 2013 Aug 12.
• Sorlen N, Hult A, Nordstrom P, Nordstrom A, Johansson J. Short-term balance training and acute effects on postural sway in balance-deficient older adults: a randomized controlled trial. BMC Sports Sci Med Rehabil. 2021 Mar 9;13(1):23. doi: 10.1186/s13102-021-00251-x.
• Low DC, Walsh GS, Arkesteijn M. Effectiveness of Exercise Interventions to Improve Postural Control in Older Adults: A Systematic Review and Meta-Analyses of Centre of Pressure Measurements. Sports Med. 2017 Jan;47(1):101-112. doi: 10.1007/s40279-016-0559-0.
• Hislop A, Collins NJ, Tucker K, Semciw AI. The association between hip strength, physical function and dynamic balance in people with unilateral knee osteoarthritis: A cross-sectional study. Musculoskelet Sci Pract. 2023 Feb;63:102696. doi: 10.1016/j.msksp.2022.102696. Epub 2022 Dec 5.
• Wang Q, Li L, Mao M, Sun W, Zhang C, Mao D, Song Q. The relationships of postural stability with muscle strength and proprioception are different among older adults over and under 75 years of age. J Exerc Sci Fit. 2022 Oct;20(4):328-334. doi: 10.1016/j.jesf.2022.07.004. Epub 2022 Aug 7.
• Steinberg N, Nemet D, Pantanowitz M, Zeev A, Hallumi M, Sindiani M, Meckel Y, Eliakim A. Longitudinal Study Evaluating Postural Balance of Young Athletes. Percept Mot Skills. 2016 Feb;122(1):256-79. doi: 10.1177/0031512516628989. Epub 2016 Feb 1.
• Sabashi K, Ishida T, Matsumoto H, Mikami K, Chiba T, Yamanaka M, Aoki Y, Tohyama H. Dynamic postural control correlates with activities of daily living and quality of life in patients with knee osteoarthritis. BMC Musculoskelet Disord. 2021 Mar 18;22(1):287. doi: 10.1186/s12891-021-04164-1.

Study record dates

Study Major Dates

• Study Start (Actual): August 23, 2026
• Primary Completion (Estimated): September 30, 2027
• Study Completion (Estimated): May 2, 2028

Study Registration Dates

• First Submitted: September 9, 2026
• First Submitted That Met QC Criteria: September 17, 2026
• First Posted (Actual): September 24, 2026

Study Record Updates

• Last Update Posted (Actual): September 24, 2026
• Last Update Submitted That Met QC Criteria: September 17, 2026
• Last Verified: September 1, 2026

More Information

Terms related to this study

• Keywords: Postural Balance, Postural Stability, Anchoring, Handheld Dynamometry
• Other Study ID Numbers: 9152

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No