Abstract
Purpose (the aim of the study): Anterior cruciate ligament (ACL) injury increases the risk of knee osteoarthritis. After ACL injury and reconstruction, the musculoskeletal function likely changes alongside the early onset of knee pain but knowledge about this is lacking. Thus, the aim was to compare knee muscle strength and movement biomechanics during walking and forward lunging between ACL reconstructed individuals with and without knee pain at least 3 years after ACL reconstruction.
Methods: This cross-sectional study included participants aged 18 to 40 years at the time of primary ACL reconstruction (semitendinosus-gracilis tendon graft), with a post-surgery time of at least 3 years. Body mass index eligibility was ≤30. Symptomatic participants were identified by a pain score of at least 3 on a verbal rating scale (0-10) in the reconstructed knee during activities of daily living within the last week, while asymptomatic participants were characterized by a pain score of 0. We measured maximal isometric quadriceps and hamstring muscle strength at 60° knee flexion (Nm/kg), and 3D movement biomechanics during walking and forward lunging. From the movement biomechanics we analyzed peak knee joint extensor moment (Nm/kg), peak quadriceps muscle force (N/kg) and peak knee joint contact force (N/kg).
Results: 122 participants (30% females) were included; 33 symptomatic and 89 asymptomatic. The average time since ACL reconstruction was approximately 75 months (6 years). The symptomatic group had lower isometric muscle strength (Table 1). The movement biomechanics were similar across groups, apart from the lower peak quadriceps muscle force during the forward lunge movement used by the symptomatic compared to the asymptomatic group (Table 1).
Conclusions: 6 years after surgery ACL reconstructed individuals with knee pain have weaker knee muscles than asymptomatic ACL reconstructed individuals but seem to employ similar walking and forward lunge biomechanics, except for a slightly lower quadriceps force generation during forward lunging. Future studies could investigate if ACL reconstructed individuals with knee pain can reduce pain via targeted strength training for both quadriceps and hamstring muscles.
Table 1. Participant demographics, muscle strength and movement biomechanics outcomes in asymptomatic and symptomatic ACL reconstructed individuals
Methods: This cross-sectional study included participants aged 18 to 40 years at the time of primary ACL reconstruction (semitendinosus-gracilis tendon graft), with a post-surgery time of at least 3 years. Body mass index eligibility was ≤30. Symptomatic participants were identified by a pain score of at least 3 on a verbal rating scale (0-10) in the reconstructed knee during activities of daily living within the last week, while asymptomatic participants were characterized by a pain score of 0. We measured maximal isometric quadriceps and hamstring muscle strength at 60° knee flexion (Nm/kg), and 3D movement biomechanics during walking and forward lunging. From the movement biomechanics we analyzed peak knee joint extensor moment (Nm/kg), peak quadriceps muscle force (N/kg) and peak knee joint contact force (N/kg).
Results: 122 participants (30% females) were included; 33 symptomatic and 89 asymptomatic. The average time since ACL reconstruction was approximately 75 months (6 years). The symptomatic group had lower isometric muscle strength (Table 1). The movement biomechanics were similar across groups, apart from the lower peak quadriceps muscle force during the forward lunge movement used by the symptomatic compared to the asymptomatic group (Table 1).
Conclusions: 6 years after surgery ACL reconstructed individuals with knee pain have weaker knee muscles than asymptomatic ACL reconstructed individuals but seem to employ similar walking and forward lunge biomechanics, except for a slightly lower quadriceps force generation during forward lunging. Future studies could investigate if ACL reconstructed individuals with knee pain can reduce pain via targeted strength training for both quadriceps and hamstring muscles.
Table 1. Participant demographics, muscle strength and movement biomechanics outcomes in asymptomatic and symptomatic ACL reconstructed individuals
| Originalsprog | Engelsk |
|---|---|
| Artikelnummer | 350 |
| Tidsskrift | Osteoarthritis and Cartilage |
| Vol/bind | 32 |
| Udgave nummer | Suppl 1 |
| Sider (fra-til) | S250 |
| Antal sider | 1 |
| ISSN | 1063-4584 |
| DOI | |
| Status | Udgivet - 2024 |