The objective of the study was to evaluate the clinical, functional, and biomechanical symptoms in patients with anterior cruciate ligament (ACL) rupture before and after ACL reconstruction. The study enrolled 20 patients and 20 healthy subjects as controls. Walking biomechanics was assessed at three time points: before surgery and three months and a year or more after surgical reconstruction. Impact loads on both sides differed significantly from the respective values before surgery (p<0.05). Walking cycle duration decreased with time after surgery. On both sides (affected and unaffected), hip movement amplitudes were significantly smaller than in control (p<0.05). They remained so in the follow-up periods after the reconstruction. Before ACL reconstruction, the amplitude of the main flexion of the knee was significantly reduced both on the affected and unaffected sides. The amplitude gradually increased after the reconstruction, and a year post-surgery, it reached, on the operated side, the same values as in the control group. Complete functional recovery of the knee joint was not achieved within a year after the ACL surgical reconstruction. The remaining changes, however, were not clinically pronounced and could only be detected by instrumental gait analysis. The compensatory processes developed bilaterally, in both the hip and knee joints.

Deforming osteoarthritis (OA) of the knee is a progressive disease associated with pain and compromised function of the joint. Typical biomechanical modifications in the gait of subjects with medial knee OA are characterized by decreased gait speed and overload on the affected limb. The borderline stage for conservative versus surgical management is Grade II OA. The aim of this research was to study preoperatively the specific features of gait, knee, and hip function in patients with Grade II medial OA. We examined 26 patients with Grade II unilateral gonarthritis with varus deformity and 20 healthy adults. Biomechanical parameters of gait were recorded using an inertial sensor system. The gait cycle (GC) slightly increased both for the affected and for the intact limb. The hip joint movements showed significant symmetrical reduction in the first flexion amplitude, as well as a symmetrical delay in full hip extension at the end of the stance phase. In the knee, the first flexion amplitude was significantly reduced on the affected side compared to healthy control. The extension amplitude in the single support phase was significantly increased in both the affected and the intact lower limbs. The swing amplitude was significantly reduced on the affected side. On the affected side, the changes were more pronounced, both in incidence and in severity. The affected knee showed a syndrome of three reduced amplitudes. In patients, walking is characterized by several groups of symptoms: those of unloading of the affected limb, those of limiting the load on the affected joint and the musculoskeletal system as a whole, and those of gait harmonization. The symptoms of unloading the affected side and those of harmonization are the common symptoms of adaptation, typical for several pathological conditions with a relatively preserved function. The intensity of the observed symptoms can help assess changes in the subject’s functional condition over time and during the treatment.

Background: Currently available studies on the long-term functional outcomes of anterior cruciate ligament (ACL) reconstruction have yielded conflicting results. The purpose of this study was to evaluate the biomechanical characteristics of walking in the long term after ACL reconstruction. Methods: The study included a test group of 18 patients (3.4 years from the date of ACL reconstruction on average) and a control group of 20 healthy subjects. Their gaits were assessed using functional tests at voluntary walking and fast-walking speeds. The biomechanical assessments utilized included spatiotemporal and kinematic parameters of walking, as well as surface electromyography (EMG) amplitudes of the main flexor-extensor muscles of the lower extremities. Results: Fast-walking speeds and the clearances of the operated-upon limbs in the patient group exceeded those in the control group. The gait cycle in the patient group was significantly longer when walking at a voluntary speed compared to the control group. In the patient group, most of the movements were symmetrical at both speeds, and the parameters did not differ from the control group. The only exception was the hip joint amplitude and the main amplitude of the knee joint flexion, which significantly and simultaneously increased when walking at a fast speed. Conclusions: In the postoperative period, at voluntary speeds, the patient group was characterized by increased amplitudes in the hip and knee joints and higher EMG amplitudes, which almost disappeared at higher speeds.

The goal of this research was to investigate functional and biomechanical symptoms in patients with chondromalacia patella. Material and Methods — Gait biomechanics was assessed in 35 patients with diagnosed unilateral chondromalacia patella and in 20 healthy adult controls. We recorded hip and knee movements, impact loads and temporal characteristics of the gait cycle (GC) during self-paced walking. Results — The temporal characteristics of gait and the impact loads remained normal in the patient population. Hip flexion amplitude decreased both on the affected (p=0.002) vs. unaffected (p=0.016) sides, compared to healthy control, whereas the amplitude phase increased on the affected (p=0.012) vs. unaffected (p=0.001) sides, versus healthy control. Hip extension and adduction-abduction amplitudes did not change significantly. Stance-phase and swing-phase knee flexion amplitudes did not change significantly. Knee extension amplitude on the affected limb increased (p=0.015), and knee rotation on the unaffected limb decreased versus control (p=0.016). The so-called stairstep symptom defined in the study was found in 83% of patients: in 23 patients bilaterally and in 6 patients unilaterally. Conclusion — Chondromalacia patella affected the gait biomechanics on both sides. The changes in the kinematic patterns during the flat-surface walking were not substantial. The only pathognomonic functional symptom of the condition was the stairstep symptom.