Effects of Orthotic Insoles on Gait Kinematics and Low-Back Pain in Patients with Mild Leg Length Discrepancy.

BACKGROUND: Mild leg length discrepancy increases biomechanical asymmetry during gait, which leads to low-back pain. Orthotic insoles with a directly integrated heel lift were used to reduce this asymmetry and thus the associated low-back pain. The aim of this study was to analyze the biomechanical adaptations of the locomotor apparatus during gait and the subjective pain ratings before and after the establishment of orthotic insole use. METHODS: Eight patients with mild leg length discrepancy (≤2.0 cm) underwent three-dimensional biomechanical analysis while walking before and after 3 weeks of orthotic insole use. Low-back pain was assessed separately before both measurement sessions using a visual analog scale. RESULTS: Analysis of the kinematic parameters highlighted individual adaptations. The symmetry index of Dingwell indicated that orthotic insoles had no significant effect on the kinematic gait parameters and an unpredictable effect across patients. Orthotic insole use significantly and systematically (in all of the patients) reduced low-back pain (P < .05), which was correlated with changes in ankle kinematics (P = .02, r = 0.80). CONCLUSIONS: The effects of orthotic insoles on gait symmetry are unpredictable and specific to each patient's individual manner of biomechanical compensation. The reduction in low-back pain seems to be associated with the improved ankle kinematics during gait.

A comparative study between isolated gastrocnemius tightness patients and controls by quantitative Gait analysis and baropodometry.

BACKGROUND: Isolated gastrocnemius tightness (IGT) has been suggested as an etiologic factor in mechanical disorders of the foot and ankle without a clear pathophysiological mechanism in the literature. We hypothesized that restricted ankle dorsiflexion inducing increased forefoot pressure in IGT patients could be this pathophysiological mechanism. METHODS: Case/control experimental observational investigation. Forty lower limbs in 20 asymptomatic IGT patients were included and compared to controls. Quantitative gait analyses coupled with dynamic baropodometry were used for comparison between groups. The primary outcome was maximum ankle dorsiflexion during stance phase. Secondary outcomes were knee flexion and forefoot pressure. RESULTS: Maximum ankle dorsiflexion and maximum forefoot pressure were similar between groups. Increased knee flexion was found in the asymptomatic IGT group. CONCLUSIONS: IGT induced compensatory knee flexion during stance phase, which probably prevents increased pressure on the forefoot by allowing ankle dorsiflexion. LEVEL OF EVIDENCE: Level IV, Case/control experimental observational investigation.

The biomechanical effects of pronated foot function on gait. An experimental study.

The relationship between foot kinematics and the development of lower extremity musculoskeletal disorders (MSD) has been the focus of recent attention. However, most studies evaluated static foot type and not dynamic foot function. The purpose was to compare lower limb and foot kinematics, and plantar pressures during gait in physically active individuals with pronated and non-pronated foot function. Foot function in 154 adult participants was documented as pronated (n = 63) or neutral (n = 91) using 2 established methods: The Foot Posture Index and the Center of Pressure Excursion Index. Difference between the groups in triplanar motion of the lower limb during barefoot gait was evaluated using a 3D motion capture system incorporating the Oxford Foot Model. Dynamic parameters of plantar pressure were recorded using a pressure platform. Anterior-posterior pelvic tilt range of motion (ROM), peak knee internal rotation, forefoot dorsiflexion ROM, peak forefoot abduction, and rearfoot eversion were all increased in those with pronated foot function. Hallux contact time and time to peak force under the medial forefoot were increased with pronated foot function, and maximal force under the lateral forefoot was reduced. Pronated foot function affected the whole lower limb kinematic chain during gait. These kinematic alterations could increase the risk of developing MSD. Further studies should elucidate the relationship between pronated foot function and MSD, and, if confirmed, foot function should be evaluated in clinical practice for patients with lower limb and low back pain.