Nordic Hamstring Exercise After ACL Reconstruction Reconstruction

University of Toledo

Status: Completed

Conditions: Neuromuscular Manifestations; Muscle Weakness; ACL Injury

Treatments: Other: Nordic Hamstring Exercise

Study type: Interventional

Funder types: Other

Identifiers

NCT05738200

202737

Details and patient eligibility

About

Anterior cruciate ligament (ACL) injuries constitute a significant portion of major knee joint injuries sustained by young, active individuals, and significantly increase risk for long-term disability. Yet the recommended solution to restore joint stability following injury--ACL reconstruction (ACLR)--does not prevent post-traumatic knee osteoarthritis (PTOA). Post-traumatic quadriceps (dys)function is a hallmark characteristic following ACLR, reported to accelerate the onset of PTOA after ACL injury, making the recovery of muscle function a primary concern to clinicians. However, hamstrings muscle function is drastically underrepresented relative to the quadriceps in the context of recovery from ACLR, which impedes the ability to develop targeted treatment approaches. Persistent hamstrings weakness is widely reported in patients who undergo ACLR with a hamstring tendon (HT) autograft, which increases ACL strain, and may contribute to higher graft failure rates in this population. To effectively treat muscular impairments, underlying neuromuscular adaptations known to occur in response to ACLR must be targeted. Eccentric exercise is uniquely suited to enhance neuromuscular function. The Nordic hamstring exercise (NHE) is a specific form of eccentric exercise that is clinically relevant and easy to implement, but has not been explored as an intervention for hamstrings neuromuscular dysfunction in patients who undergo ACLR with HT. To establish an evidence-based treatment model, the investigators will use a single-blind, randomized controlled clinical trial to establish the feasibility and efficacy of a 4-week NHE protocol in patients who undergo ACLR with HT. Separate factorial ANOVAs will be used to assess the effects of group (NHE, control) and time (baseline, 4 weeks) on selected outcomes. Effect sizes will be calculated for within- and between-group comparisons. The investigators expect to observe improvements in hamstrings neuromuscular function following the NHE protocol, and that those improvements will be greater than the control group. Additionally, the investigators expect the protocol to be feasible in terms of intervention adherence and patient retention. This study will identify specific barriers to the implementation of NHE in patients who undergo ACLR with HT, and will provide support for the application of an easy to implement clinical intervention able to address a complex neurophysiological problem.

Enrollment: 23 patients

Sex: All

Ages: 18 to 35 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Age 18-35
• History of primary, unilateral ACL reconstruction (ACLR) with hamstrings tendon autograft

Exclusion criteria

• Lower extremity orthopedic surgery prior to ACLR
• Post-surgical complication (e.g. infection, delayed healing)
• Multiple ligament knee injury
• Treated articular cartilage lesion
• Known history of knee osteoarthritis
• Concussion within 6 months
• History of neurological disorder
• Currently taking prescription medication that may alter neural excitability (e.g. stimulants, depressants)

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

---

23 participants in 2 patient groups

Nordic Hamstring Exercise

Experimental group

Description:

A 4-week (10 session), progressive, Nordic Hamstring Exercise (NHE) protocol will be used for this study.

Treatment:

Other: Nordic Hamstring Exercise

Control

No Intervention group

Description:

Patients randomized to the control group will be instructed to avoid any changes to their normal routine (e.g., physical activity level, strength training, etc.). An investigator not involved in data collection will communicate with patients in the control group on a weekly basis to ensure they have not changed their physical activity level and do not have any questions. Patients randomized to the control group will participate in a minimum of 2 study visits at baseline and 4 weeks. These individuals will have the option to open enroll in the intervention group at the completion of their original 4-week study period. Those who choose to enroll in the intervention group at this time will return for 11 additional visits to complete the NHE protocol (visits 3-12) and final assessment (visit 13)