Effects of External Upper Limb Loading on Gait and Trunk Muscle Activity in Cardiac Rehabilitation Patients (ND)

Biomechanical, Electromyographic, and Baropodometric Assessment of Gait Parameters and Trunk-Stabilizing Muscle Activity at Baseline and Under Unilateral and Bilateral Upper Limb Loading in Patients Undergoing Cardiac Rehabilitation

This study examines how external loading applied to the upper limbs affects gait parameters and the activity of selected trunk- and pelvis-stabilizing muscles (erector spinae, gluteus medius, tensor fasciae latae, external oblique) in patients undergoing cardiac rehabilitation. Participants are medically stable adults (18-80 years) referred to cardiac rehabilitation following a cardiac event or procedure, meeting NYHA class I-II criteria, with no unstable coronary disease, uncontrolled hypertension, neurological disease, or other exclusion criteria.

Participants will walk on a treadmill at 1 km/h, 3 km/h and 5 km/h under three conditions: without load, with unilateral upper-limb loading, and with bilateral upper-limb loading. Muscle activity will be recorded using surface electromyography (sEMG), and plantar pressure/gait parameters will be recorded simultaneously using baropodometry integrated into the treadmill. The procedure is non-invasive, does not breach the skin, and does not involve any additional intervention beyond standard rehabilitation. To contextualize functional outcomes, previously collected exercise stress test results (performed independently by the treating physician before and after cardiac rehabilitation, as part of routine clinical care) will be retrieved from participants' medical records for comparison; this is a retrospective data comparison, not an additional study intervention.

No financial compensation is provided. Each participant will receive an individual report of their sEMG and gait findings with professional interpretation. Risks are minimal and limited to transient skin irritation from electrodes and mild, temporary muscle fatigue or soreness typical of moderate exercise. Participants may withdraw at any time.

Study Overview

• Status: Active, not recruiting
• Conditions: Cardiovascular Diseases; Cardiac Rehabilitation; Exercise Tolerance; Muscle Contraction; Gait Abnormality
• Intervention / Treatment: Other: External Upper Limb Loading During Treadmill Walking

Detailed Description

Study Design and Rationale This is a prospective, observational biomechanical and neuromuscular study evaluating the effect of external upper-limb loading (unilateral, dominant and non-dominant side, and bilateral) on gait parameters and the activity of selected trunk- and pelvis-stabilizing muscles in patients undergoing cardiac rehabilitation. Existing literature on muscle activity during loaded walking is limited, and the extent and pattern of these changes are not yet well characterized. This study aims to address that gap and provide data relevant to rehabilitation practice, including load standardization in physiotherapy.

Participants 50-60 adults (18-80 years) referred to cardiac rehabilitation following a cardiac event or procedure (including patients several years post-event), medically stable and classified as NYHA class I-II. Recruitment uses stratified random sampling, with strata based on sex and age to ensure balanced representation. Exclusion criteria include unstable coronary artery disease, recent myocardial infarction (<4 weeks), NYHA class III-IV heart failure, uncontrolled hypertension, cardiac arrhythmias, neurological or neurodegenerative disease, acute lower-limb or spinal injury, gait pathology, poorly controlled diabetes with hypoglycemia risk, pregnancy, BMI >35 kg/m², and lack of consent.

Procedures Participants complete a health/medical history questionnaire followed by a preliminary diagnostic assessment of physical capacity. During the main protocol, participants walk on a treadmill at 1 km/h, 3 km/h and 5 km/h under three loading conditions (no load, unilateral, bilateral), while sEMG records activity of the erector spinae, gluteus medius, tensor fasciae latae, and external oblique muscles, and baropodometry (integrated into the treadmill) simultaneously records plantar pressure and gait parameters.

Additionally, exercise stress test results obtained by the participant's physician before and after cardiac rehabilitation - performed independently of this study as part of routine clinical care - are retrieved from medical records by a research team member with institutional authorization to access patient data, and compared with the sEMG/gait findings. No stress testing is performed by the research team as part of this protocol.

Ethical and Regulatory Compliance The protocol has been reviewed and approved by the relevant bioethics committee. Written informed consent is obtained from all participants prior to participation. Access to participants' medical records (stress test results) is conducted under existing institutional authorization held by a research team member.

• Study Type: Observational
• Enrollment (Actual): 60

Contacts and Locations

Study Locations

• Poland
  • Słupsk, Poland, 76-200
    • Wojewódzki Szpital Specjalistyczny w Słupsku

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

Participants are adult patients referred to a hospital-based cardiac rehabilitation program (Wojewódzki Szpital Specjalistyczny w Słupsku) following a cardiac event or procedure, who are medically stable and undergoing supervised outpatient/inpatient cardiac rehabilitation. Assessments are conducted by the biomechanics laboratory (Pomeranian University in Słupsk).

Description

Inclusion Criteria:

• Age ≥18 and ≤80 years
• Referred to cardiac rehabilitation following a cardiac event or procedure
• Medically stable, classified as NYHA class I-II
• Able and willing to provide informed consent
• Willing and able to complete the study procedures
• Able to safely perform treadmill walking and exercise testing
• No cardiological or pulmonological contraindications to exercise
• No limb deformities or gait pathology identified on clinical interview

Exclusion Criteria:

• Unstable coronary artery disease, recent myocardial infarction (<4 weeks), or recent revascularization (<4 weeks)
• Heart failure NYHA class III-IV
• Uncontrolled hypertension
• Cardiac arrhythmias
• Neurological or neurodegenerative disease
• Acute lower-limb or spinal injury, musculoskeletal deformity, or significant pain affecting gait
• Diabetes mellitus with hypoglycemia tendency
• Pregnancy
• BMI >35 kg/m²
• Lack of informed consent

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Cardiac Rehabilitation Patients; Adult patients (N=60) (18-80 years) referred to cardiac rehabilitation following a cardiac event or procedure, medically stable and classified as NYHA class I-II. Each participant is assessed at two time points: at the start of cardiac rehabilitation (Day 1) and approximately 20 rehab-days later, following completion of the rehabilitation program. At each session, participants walk on a treadmill at 3 km/h and 5 km/h under three loading conditions (no load, unilateral upper-limb loading, bilateral upper-limb loading), while gait parameters and trunk/pelvic muscle activity are recorded.

Other: External Upper Limb Loading During Treadmill Walking; Participants walk on a treadmill at controlled speeds (3 km/h and 5 km/h) under three conditions: without external load, with unilateral upper-limb loading (dominant and non-dominant side), and with bilateral upper-limb loading. Gait parameters and lower-limb/trunk muscle activity are recorded simultaneously via surface electromyography (sEMG) and baropodometry integrated into the treadmill system. This is a non-invasive assessment procedure, not a therapeutic intervention.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean sEMG-Derived Neuromuscular Asymmetry Index	Asymmetry index from normalized RMS sEMG amplitude of erector spinae, gluteus medius, tensor fasciae latae, and external oblique, dominant vs. non-dominant side during unloaded treadmill walking. Expressed as a percentage; 0% indicates perfect symmetry, higher values greater asymmetry. Unit of Measure: percentage · Measure Type: Mean	Day 1 of cardiac rehabilitation (baseline)
Mean Plantar Pressure Distribution Asymmetry Index	Asymmetry index from baropodometric plantar pressure distribution, dominant vs. non-dominant lower limb during unloaded treadmill walking. Expressed as a percentage; 0% indicates perfect symmetry, higher values greater asymmetry. Unit of Measure: percentage · Measure Type: Mean	Day 1 of cardiac rehabilitation (baseline)
Mean Spatiotemporal Gait Asymmetry Index	Asymmetry index from spatiotemporal gait parameters (step length, stance and swing phase duration), dominant vs. non-dominant lower limb during unloaded treadmill walking. Expressed as a percentage; 0% indicates perfect symmetry, higher values greater asymmetry. Unit of Measure: percentage · Measure Type: Mean	Day 1 of cardiac rehabilitation (baseline)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean Change from Baseline in sEMG-Derived Neuromuscular Asymmetry Index After Rehabilitation	Mean change from baseline (Day 1) to the end of the rehabilitation program (after 20 sessions, approximately 30 days) in the sEMG-derived neuromuscular asymmetry index (normalized RMS sEMG amplitude of erector spinae, gluteus medius, tensor fasciae latae, and external oblique), during unloaded treadmill walking at 1, 3, and 5 km/h. Expressed in percentage points; a negative value indicates reduced asymmetry. Unit of Measure: percentage points · Measure Type: Mean	After completion of 20 rehabilitation sessions (approximately 30 days)
Mean Change from Baseline in Plantar Pressure Distribution Asymmetry Index After Rehabilitation	Mean change from baseline (Day 1) to the end of the rehabilitation program (after 20 sessions, approximately 30 days) in the baropodometric plantar pressure distribution asymmetry index, during unloaded treadmill walking at 1, 3, and 5 km/h. Expressed in percentage points; a negative value indicates reduced asymmetry. Unit of Measure: percentage points · Measure Type: Mean	After completion of 20 rehabilitation sessions (approximately 30 days)
Mean Change from Baseline in Spatiotemporal Gait Asymmetry Index After Rehabilitation	Mean change from baseline (Day 1) to the end of the rehabilitation program (after 20 sessions, approximately 30 days) in the spatiotemporal gait asymmetry index (step length, stance and swing phase duration), during unloaded treadmill walking at 1, 3, and 5 km/h. Expressed in percentage points; a negative value indicates reduced asymmetry. Unit of Measure: percentage points · Measure Type: Mean	After completion of 20 rehabilitation sessions (approximately 30 days)

Collaborators and Investigators

• Sponsor: Pomeranian University in Slupsk
• Investigators: Principal Investigator: Wojciech Nawos-Wysocki, MSc PT, Pomeranian University in Słupsk; Study Director: Agnieszka Grochulska, PhD, MSc PT, Pomeranian University in Słupsk

Study record dates

Study Major Dates

• Study Start (Actual): May 15, 2026
• Primary Completion (Estimated): August 31, 2026
• Study Completion (Estimated): August 31, 2026

Study Registration Dates

• First Submitted: August 12, 2026
• First Submitted That Met QC Criteria: September 2, 2026
• First Posted (Actual): September 3, 2026

Study Record Updates

• Last Update Posted (Actual): September 3, 2026
• Last Update Submitted That Met QC Criteria: September 2, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Keywords: gait analysis; cardiac rehabilitation; surface electromyography; external loading; trunk and pelvic muscle activation; treadmill walking; upper limb loading
• Additional Relevant MeSH Terms: Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Cardiovascular Diseases; Mobility Limitation
• Other Study ID Numbers: K01

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: De-identified individual participant data supporting the specific results reported in each peer-reviewed publication arising from this study will be made available, typically as supplementary material accompanying the relevant article. Data are shared on a per-publication basis rather than as a complete raw dataset
• IPD Sharing Time Frame: Data underlying each publication will be made available at the time of publication of that article, as supplementary material.
• IPD Sharing Access Criteria: De-identified data supporting published results will be provided as supplementary files with each publication. Data beyond what is published may be requested from the corresponding author for legitimate research purposes and will be reviewed on a case-by-case basis.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL

Drug and device information, study documents

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