Isoinertial Rehabilitation in Recovering Hamstring Strength Following Surgical Anterior Cruciate Ligament Reconstruction

"Efficacy of Isoinertial Rehabilitation in Recovering Hamstring Strength Following Surgical Anterior Cruciate Ligament Reconstruction: a Randomized Controlled Trial"

The present experimental study aims to evaluate the effectiveness and tolerability of isoinertial strength training of the hamstrings using machines in patients with ACL-R during the intermediate post-intervention phases.

Study Overview

• Status: Not yet recruiting
• Conditions: Anterior Cruciate Ligament Injuries; Anterior Cruciate Ligament Rupture; ACL Injury; ACL Tear; ACL Sprain
• Intervention / Treatment: Other: Strength Training; Device: Isoinertial training

Detailed Description

A proper post-operative rehabilitation program is essential for a positive outcome after anterior cruciate ligament (ACL) reconstruction surgery, a procedure known to cause morpho-functional issues in the short, medium, and long term in individuals who undergo it. Generally, after an initial rehabilitation phase focused on protecting the healing process of the new ligament and regaining range of motion, the rehabilitation path focuses on muscular strengthening and neuromuscular control of both lower limbs. It has been demonstrated that deficits in extensor and flexor muscle strength, as well as their strength ratios, increase the risk of re-injury. Specifically, in athletes, the rate of recurrence, defined as a new injury to the same or opposite side ACL, is considerably high.

High-intensity resistance training of the operated limb has often been contraindicated in the early post-operative period, as it was considered detrimental to the new ligament, joint cartilage, and surrounding soft tissues. However, recent studies suggest that the early application of progressive eccentric-focused exercises, even with high loads, can be safely used to increase muscle volume and strength levels in individuals undergoing ACL reconstruction (ACL-R). Therefore, eccentric reinforcement can be a valid alternative to traditional concentric work for improving lower limb muscle strength after ACL-R.

Recently, it has been demonstrated that strength training using isoinertial machines in healthy individuals leads to positive chronic adaptations in terms of strength recovery, power, and functional capacities such as sprinting, change of direction, and agility. Isoinertial training allows for exercises in both closed and open kinetic chains, as well as multiplanar motor activities. The combination of concentric phases with subsequent eccentric overload allows for the development of high levels of strength and power with low energy cost, promotes intermuscular coordination, preferentially recruits motor units with high activation thresholds, and increases cortical activity. Increased muscle activation, particularly during eccentric muscle actions, indicates a higher mechanical load and a greater training stimulus, leading to better and earlier protein synthesis and subsequent muscle hypertrophy compared to traditional resistance training. Furthermore, the metabolic cost required for an eccentric contraction is about a quarter of that for a concentric contraction at the same external load. Therefore, at the same contraction velocity, eccentric contractions allow for a higher force expression.

While the use of isoinertial equipment is well-established in healthy individuals, scientific evidence regarding its use in rehabilitation protocols is currently limited. The use of eccentric overload, in addition to improving parameters related to muscle strength and power, seems to promote tendon remodeling due to an increased production of fibroblasts and collagen, generated by the higher mechanical load compared to traditional concentric exercise. In lower limb pathologies, isoinertial rehabilitation following injury can be a valid alternative to traditional strength training for the development of muscle hypertrophy and function. However, specific studies investigating the effects of isoinertial rehabilitation in the intermediate stages of recovery following ACL-R and monitoring the tolerability of the treatment are currently lacking.

• Study Type: Interventional
• Enrollment (Estimated): 52
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• having undergone ACL-R surgery following a unilateral rupture
• with reconstructive surgical technique using autograft tendon from the semitendinosus and gracilis muscles (ST-GR), also in the presence of meniscal injuries treated with selective meniscectomy or meniscal suturing.
• Participants must report a level of physical activity between 5 and 10 assessed using the Tegner scale, and have completed the third month of post-operative rehabilitation

Exclusion Criteria:

• concurrent injuries involving other ligaments of the knee, cartilage injuries requiring surgery to repair the damage
• previous ACL reconstruction (re-rupture with a new ACL reconstruction) on the knee affected by the new ACL injury.
• Additionally, if the level of pain prevents the subject from performing the functional tests, they will not be included in the study

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Gold Rehab + Strength Training; Gold standard rehabilitation plus traditional strength training with overloads	Other: Strength Training; The subjects included in the study will undergo traditional muscle strengthening for a period of 4 weeks, with 2 sessions per week consisting of strength training using classic exercises
Experimental: Gold Rehab + Isoinertial; Gold standard rehabilitation with the inclusion of isoinertial training	Device: Isoinertial training; The subjects included in the study will undergo traditional muscle strengthening for a period of 4 weeks, with 2 sessions per week consisting of strength training using isoinertial machines

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Active and passive range of motion (ROM) of the knee joint	Day 0
Active and passive range of motion (ROM) of the knee joint	Day 28
Strength of the thigh flexor and extensor muscles	Day 0
Strength of the thigh flexor and extensor muscles	Day 28
Qualitative analysis of the Single Leg Squat	Day 0
Qualitative analysis of the Single Leg Squat	Day 28
Maximal Hip Flexion Active Knee Extension Test	Day 0
Maximal Hip Flexion Active Knee Extension Test	Day 28
Quantitative analysis of the Drop Jump, with frontal and sagittal views	Day 0
Quantitative analysis of the Drop Jump, with frontal and sagittal views	Day 28

Collaborators and Investigators

• Sponsor: Università degli studi di Roma Foro Italico

Study record dates

Study Major Dates

• Study Start (Estimated): January 1, 2024
• Primary Completion (Estimated): October 31, 2024
• Study Completion (Estimated): October 31, 2024

Study Registration Dates

• First Submitted: July 28, 2023
• First Submitted That Met QC Criteria: September 25, 2023
• First Posted (Actual): October 3, 2023

Study Record Updates

• Last Update Posted (Actual): October 3, 2023
• Last Update Submitted That Met QC Criteria: September 25, 2023
• Last Verified: September 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Leg Injuries; Knee Injuries; Wounds and Injuries; Rupture; Anterior Cruciate Ligament Injuries
• Other Study ID Numbers: ISOHAMACL

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

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