Lower extremity neuromuscular compensations during instrumented single leg hop testing 2-10 years following ACL reconstruction

BACKGROUND

This study compared lower extremity EMG activation and sagittal plane kinematics of subjects at a minimum of 2 years post-successful ACL reconstruction and rehabilitation during instrumented single leg hop testing.

METHODS

Comparisons were made based on subject responses to the following question, "compared to prior to your knee injury how capable are you now in performing sports activities"? Group 1=very capable, Group 2=capable, and Group 3=not capable. In addition to EMG (1000 Hz) and kinematic (60 Hz) data, subjective knee function, internal health locus of control, sports activity characteristics (intensity, frequency) pre-knee injury, and at follow-up were also compared.

RESULTS

Group 3 had lower perceived knee function, decreased perceived sports intensity, and more subjects with decreased sports activity intensity by two levels compared to pre-injury values. Perceived function scores, anterior laxity measurements and grades were similar between groups. During single leg hop propulsion and landing Group 1 (very capable) had greater involved lower extremity gluteus maximus and medial hamstring activation amplitudes than Group 3 (not capable). Perceived sports capability was related to better subjective knee function, and higher perceived sports activity intensity.

CONCLUSION

Neuromuscular compensations suggesting a hip bias with increased gluteus maximus and medial hamstring activation were identified at the involved lower extremity among most subjects who perceived high perceived sports capability compared to pre-injury status. These compensations may be related to a permanent neurosensory deficit, and its influence on afferent pathway changes that influence CNS sensorimotor re-organization.

Alterations in physical and neurocognitive wellness across recovery after ACLR: A preliminary look into learned helplessness

OBJECTIVES

Neural alterations after anterior cruciate ligament reconstruction (ACLR) may initiate a maladaptive neurocognitive response (learned helplessness [LH]). Understanding the interrelationships between neural inhibition, quadriceps function and psychological responses can provide clinicians areas to target during recovery. The purpose was to longitudinally evaluate neural excitability, strength and self-reported LH after ACL injury and to explore the relationship between these measures and knee mechanics and patient reported function.

DESIGN

Case-series.

SETTING

University.

PARTICIPANTS

Eight patients were evaluated across recovery after ACL injury.

MAIN OUTCOME MEASURES

Neural activity, quadriceps function, and self-reported LH were evaluated at pre-surgery, 3-months post-ACLR and at the time of return to play (RTP).

RESULTS

Patients presented with higher helplessness between 3-months and RTP. Neural excitability and quadriceps function were variable and associated with various aspects of LH. These findings indicate a systemic inability to generate appropriate neural signaling to the quadriceps and highlights how these changes may influence perceived helplessness and overall function after ACLR.

CONCLUSIONS

LH is related to both measures of physical function and neural outcomes and varies across recovery. This may provide clinicians with a feasible clinical tool that has the potential to identify a variety of impairments arising after ACLR.

Sports activity level after ACL reconstruction is predicted by vastus medialis or vastus medialis obliquus thickness, single leg triple hop distance or 6-m timed hop, and quality of life score

PURPOSE

Recovery after anterior cruciate ligament reconstruction (ACLR) may take > 2 years, and younger athletes have higher re-injury risk. The purpose of this prospective longitudinal study was to determine how the early to mid-term Tegner Activity Level Scale (TALS) scores of athletically active males ≥ 2 years post-ACLR follow-up was predicted by bilateral isokinetic knee extensor and flexor torque, quadriceps femoris thickness, single leg hop test performance, and self-reported knee function (Knee Injury and Osteoarthritis Outcome Score (KOOS); International Knee Documentation Committee (IKDC) Subjective Assessment score).

METHODS

After ACLR with a hamstring tendon autograft and safely returning to sports at least twice weekly, 23 men (18.4 ± 3.5 years of age) were evaluated at final follow-up (mean = 4.5, range = 2-7 years). Exploratory forward stepwise multiple regression was used to determine the relationship between independent surgical and non-surgical lower limb variables peak concentric isokinetic knee extensor-flexor torque at 60°/sec and 180°/sec, quadriceps femoris muscle thickness, single leg hop test profile results, KOOS subscale scores, IKDC Subjective Assessment scores, and time post-ACLR on TALS scores at final follow-up.

RESULTS

Subject TALS scores were predicted by KOOS quality of life subscale score, surgical limb vastus medialis obliquus (VMO) thickness, and surgical limb single leg triple hop for distance (SLTHD) performance. Subject TALS scores were also predicted by KOOS quality of life subscale score, non-surgical limb vastus medialis (VM) thickness, and non-surgical limb 6 m single leg timed hop (6MSLTH) performance.

CONCLUSION

TALS scores were influenced differently by surgical and non-surgical lower extremity factors. At ≥ 2 years post-ACLR, ultrasound VM and VMO thickness measurements, single leg hop tests that challenge knee extensor function, and self-reported quality of life measurements predicted sports activity levels. The SLTHD test may be better than the 6MSLTH for predicting long-term surgical limb function.