Effect of LL-BFRE Training on Volitional Muscle Activation in Subjects with Knee Joint Impairment

NCT ID: NCT06603532

Last Updated: 2024-10-03

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 36 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2019-04-16
• Study Completion Date: 2020-09-09

Brief Summary

The aim of this study was to investigate whether 4 weeks of exercise training against low mechanical resistance in combination with partial blood flow restriction has an additional therapeutic effect on the patients' ability to activate the knee extensor muscle. Patients with chronic deficits in muscle strength due to knee injuries or surgery on one leg were invited to participate in this study on a completely voluntary basis.

Detailed Description

The effects of low-load exercise with blood flow restriction (BFR) on the ability to voluntarily activate skeletal muscle in people with joint injuries are poorly understood. The aim of our study was to investigate the effects of low-load BFR training on the level of voluntary activation (AL) of the quadriceps femoris muscle assessed using the interpolated twitch technique in people with different knee joint injuries. Thirty-three orthopedic patients assigned to either the BFR group or the SHAM-BFR group participated in the study. Over a period of four weeks, the participants completed 12 training sessions of unilateral knee extension and leg press at 30 RM. The BFR group trained with a pneumatic cuff-induced blood flow restriction (pressure = 120-140 mmHg), while the SHAM-BFR group trained with a sham blood flow restriction (pressure = 20 mmHg) that did not interfere with normal muscle perfusion. The assessment of knee muscle capacity and function consisted of dynamometric measurements of maximal isometric strength and endurance of the knee extensor muscles, level of voluntary muscle activation, surface electromiography, pain intensity and assessment of perceived exertion. All tests and measurements were performed twice, once before the intervention (baseline) and once at the end of the 4-week training period (POST).

Conditions

Arthrogenic Muscle Inhibition; Knee Injuries; Knee Surgery

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: DOUBLE

Study Groups

low-load blood flow restriction (BFR) resistance training

Group of patients that performed the experimental exercise training against low mechanical resistance (workload) with blood flow restriction (BFR) in the active thigh muscles.

Group Type: EXPERIMENTAL

low-load blood flow restriction (BFR) training

Intervention Type: OTHER

The training program lasted four weeks with three training sessions per week, for a total of 12 training sessions. Participants in the BFR group exercised with blood flow restriction caused by an inflatable cuff placed on the proximal part of the thigh and inflated to 120-140 mmHg. Subjects trained against the maximum mechanical resistance they could overcome thirty times (30 repetitions maximum; 30 RM). All training sessions were performed under the supervision of a physiotherapist and included leg press and knee extension exercises.

low-load resistance training

Group of patients that performed exercise training against low mechanical resistance (workload) with sham blood flow restriction (SHAM-BFR) in the active thigh muscles.

Group Type: SHAM_COMPARATOR

low-load resistance training

Intervention Type: OTHER

The training program lasted four weeks with three training sessions per week, for a total of 12 training sessions. Participants in SHAM-BFR group performed an identical exercise protocol as experimental (BFR) group, while having thigh cuff inflated to only 20 mmHg, which did not affect normal muscle blood flow. Subjects trained against the maximum mechanical resistance they could overcome thirty times (30 repetitions maximum; 30 RM). All training sessions were performed under the supervision of a physiotherapist and included leg press and knee extension exercises.

Interventions

low-load blood flow restriction (BFR) training

The training program lasted four weeks with three training sessions per week, for a total of 12 training sessions. Participants in the BFR group exercised with blood flow restriction caused by an inflatable cuff placed on the proximal part of the thigh and inflated to 120-140 mmHg. Subjects trained against the maximum mechanical resistance they could overcome thirty times (30 repetitions maximum; 30 RM). All training sessions were performed under the supervision of a physiotherapist and included leg press and knee extension exercises.

Intervention Type: OTHER

low-load resistance training

The training program lasted four weeks with three training sessions per week, for a total of 12 training sessions. Participants in SHAM-BFR group performed an identical exercise protocol as experimental (BFR) group, while having thigh cuff inflated to only 20 mmHg, which did not affect normal muscle blood flow. Subjects trained against the maximum mechanical resistance they could overcome thirty times (30 repetitions maximum; 30 RM). All training sessions were performed under the supervision of a physiotherapist and included leg press and knee extension exercises.

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• no systemic illness,
• no history of injuries to the contralateral knee,
• pain intensity during exercise ≤ 2 on numeric pain rating scale (0-10).

Exclusion Criteria

• neuromuscular impairments,
• spine or other lower limb injuries,
• presence or history of any vascular diseases or deep vein thrombosis
• pain intensity during exercise ≥ 3 on numeric pain rating scale (0-10).

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 55 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

University Medical Centre Ljubljana

OTHER

Sponsor Role: collaborator

University of Primorska

OTHER

Sponsor Role: collaborator

University of Ljubljana

OTHER

Sponsor Role: lead

Responsible Party

Alan Kacin

Head of Laboratory

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Alan Kacin, PhD, PT, Prof

Role: PRINCIPAL_INVESTIGATOR

University of Ljubljana, Faculty of Health Studies

Locations

University of Primorska, Faculty of Health Sciences

Izola, , Slovenia

University of Ljubljana, Faculty of Health Sciences

Ljubljana, , Slovenia

Countries

Slovenia

Other Identifiers

P3-0043

Identifier Type: OTHER_GRANT

Identifier Source: secondary_id

20190041; 20200063

Identifier Type: OTHER_GRANT

Identifier Source: secondary_id

0120-496-2018-8

Identifier Type: -

Identifier Source: org_study_id