Low Back Pain and Hamstring-to-Quadriceps Strength Ratio in Military Personnel (LBP-H/Q ratio)

Association Between Low Back Pain and Hamstring-to-Quadriceps Strength Ratio in Lithuanian National Defence Volunteer Forces Personnel

The aim of this study was to determine the association between low back pain and the strength of knee flexor and extensor muscles in Lithuanian National Defence Volunteer Forces personnel.

Study Overview

• Status: Completed
• Conditions: Low Back Pain; Military Personnel

Detailed Description

This cross-sectional study investigated the association between low back pain (LBP) and the hamstring-to-quadriceps (H/Q) strength ratio in personnel of the Lithuanian National Defence Volunteer Forces. Active-duty volunteers with and without LBP underwent isokinetic testing of knee flexor and extensor muscle strength using a Biodex System 4 Pro dynamometer at angular velocities of 60°/s and 120°/s. Hamstring strength, quadriceps strength, H/Q ratios, and inter-limb asymmetries were assessed to explore potential associations with low back pain in this military population.

• Study Type: Observational
• Enrollment (Actual): 71

Contacts and Locations

Study Locations

• Lithuania
  • LT
    • Kaunas, LT, Lithuania, 44221
      • Department of health promotion and rehabilitation

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

The study population included active-duty Lithuanian National Defence Volunteer Forces personnel recruited for participation in this cross-sectional analysis

Description

Inclusion Criteria:

• The study participants consisted of a targeted population of Lithuanian National Defence Volunteer Forces personnel

Exclusion Criteria:

• Individuals with a clinically diagnosed low back pain disorder or acute episodes of low back pain were excluded

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
Military personnel; Targeted population of Lithuanian National Defence Volunteer Forces personnel

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Low back pain prevalence	Participants were asked whether they had experienced low back pain during the past 12 months (yes/no). Participants who responded "yes" were classified into the low back pain group.	Baseline
Low back pain intensity	LBP intensity was assessed using the Visual Analogue Scale (VAS, 0-10) , where 0 - no pain, and 10 - worst imaginable pain.	Baseline
Low back pain duration	Participants were asked to indicate LBP duration. LBP pain duration was classified as acute (<3 months) or chronic (≥3 months)	Baseline
Muscle strength peak torque	Muscle strength was assessed using the Biodex System 4 isokinetic dynamometer. Participants were instructed to avoid vigorous physical activity 24 hours before testing and refrain from eating for at least 2 hours prior to assessment. A 10-minute warm-up on a cycle ergometer (50-60 W) and light dynamic exercises were performed before testing. Participants were seated with the backrest at 85° and hip flexion at 90°. The dynamometer axis was aligned with the lateral femoral epicondyle, and the lower leg was secured 2-3 cm above the ankle. The range of motion was set from 70° knee flexion to full extension. The trunk and tested limb were stabilized using straps. Testing included 5 repetitions at 60°/s and 10 repetitions at 120°/s, with a 30-second rest interval between sets. Prior to testing, participants performed 3-5 familiarization repetitions. Peak torque normalized to body weight (Nm/kg) was recorded.	Baseline
Average torque	Was measured in Nm	Baseline
Muscle power	in W	Baseline
Body weight	Measured in kg	Baseline
Body height	Measured in meters	Baseline
Age	Measured in years	Baseline

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Previous injuries	Participants were asked whether they had lumbar or lower limb injuries during the past 12 months that could influence the results (yes / no).	Baseline

Collaborators and Investigators

• Sponsor: Lithuanian Sports University

Publications and helpful links

General Publications

• Dudoniene V, Zemaitis E. Prevalence and risk factors of low back pain among Lithuanian national defense volunteer forces. BMC Musculoskelet Disord. 2025 Oct 17;26(1):978. doi: 10.1186/s12891-025-09235-1.

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2026
• Primary Completion (Actual): January 5, 2026
• Study Completion (Actual): April 22, 2026

Study Registration Dates

• First Submitted: April 24, 2026
• First Submitted That Met QC Criteria: May 18, 2026
• First Posted (Actual): May 26, 2026

Study Record Updates

• Last Update Posted (Actual): May 26, 2026
• Last Update Submitted That Met QC Criteria: May 18, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: strength; hamstrings; quadriceps muscle
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Back Pain; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Low Back Pain
• Other Study ID Numbers: Lithuanian Sports University31

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: Individual participant data (IPD) will not be publicly shared due to ethical and privacy restrictions related to participant confidentiality and informed consent agreements.Military personnel is sensitive

Drug and device information, study documents

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