Stephanie M. Trigsted et al., Greater fear of reinjury is related to stiffened jump-landing biomechanics and muscle activation in women after ACL reconstruction, april 2018, Knee Surgery, Sports Traumatology, Arthroscopy, DOI 10.1007/s00167-018-4950-2
Fear of reinjury is the most commonly cited reason for patients choosing not to return to sport. ACL injuries, reconstruction, and early rehabilitation are commonly painful experiences. Some patients may associate the pain with certain movements or activities and begin to avoid them. Alternatively, they may employ compensatory techniques or alter movement patterns in an attempt to avoid pain and reinjury.
This theoretical model is supported in the previous research in patients with other orthopedic injuries. For example, high fear of reinjury was associated with decreased sagittal plane motion and increased muscle guarding in patients with low back pain.
While the model is supported with the previous work, it has not yet been explored in an ACLR population.
The Tampa Scale of Kinesiophobia-11 (TSK-11) has been used in patients with ACL injuries to investigate fear f reinjury before, immediately after, and up to 20 years following ACLR. High fear of reinjury has been linked to
- low rates of return to sport
- selfreported activity
- lower self-reported knee function
- lower quadriceps strength
- worse hop performance
- greater risk of reinjury
Furthermore patients with ACLR exhibit a multitude of biomechanical deficits during functional tasks, like
- landing from a jump
- cutting tasks
- jump stops when compared to healthy individuals
- decreased hip and knee flexion during landing
- increased hip adduction and lateral trunk flexion.
- patients shift demands away from their injured limb and towards their healthy limb during functional tasks
36 female participants with unilateral ACLR was recruited from the university and surrounding communities. Inclusion criteria were less than 4 years from the time of surgery; 18–27 years of age; no history of multiple ligament reconstructions (MCL, PCL, and LCL); and report no lower extremity injuries in the past 3 months (hip, knee, ankle, or foot).
The participants performed five standardized jump-landing task from a 30 cm box to a force plates. Practice trials were allowed until the participant could perform the task comfortably. EMG data was used to measure muscle activity and the sensors were placed over the muscle belly, vastus lateralis, (VL), rectus femoris (RF), gluteus maximus (Gmax), gluteus medius (Gmed), biceps femoris (biceps), semimembranosus (semi), lateral gastrocnemius (latG) and medial gastrocnemius (medG).
The relationships between the TSK-11 total score and kinematic variables found a significant, negative relationship with knee flexion (p=0.006), hip flexion (p=0.003), trunk flexion (p=0.013) and a positive relationship with hip adduction (p=0.007). Relationships between TSK-11 scores and muscle activation found that Fear of reinjury had a significant, positive relationship with gluteus max pre-activation (p=0.001) and moderate, though non-significant, association with vastus lateralis and rectus femoris pre-activation There were not any significant relationships between fear of reinjury and muscle activation during the landing phase of the jump landing.
The most important finding of this study is that greater fear of reinjury is associated with stiffened movement patterns in the sagittal and transverse planes, greater motion in the frontal plane, and greater preparatory muscle activation.
Fear of reinjury appears to be related to movement patterns in females with a history of ACLR. Individuals with greater fear demonstrated stiffer landings in the sagittal plane and increased frontal plane motions. Fear is important in determining which patients will return to sport but may also be related to stiffened movement patterns during a jump landing.
Clinicians should evaluate psychological and emotional consequences of injury in addition to the physical consequences as they appear to be related.
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