Background and Objectives. Bilateral knee osteoarthritis (KOA) in older patients compromises mobility and quality of life. Gait analysis provides objective, reproducible measures of physical performance. This study evaluated the integration of gait analysis for longitudinal monitoring and personalized rehabilitation, while ultrasound was performed only at baseline for characterization and did not inform adjustments to the interventions. Materials and Methods. We conducted a 6-week, randomized, parallel-group clinical trial including 130 participants aged ≥65 years. Patients were randomized to a Study Group (SG, n = 64) receiving 10 sessions of a comprehensive rehabilitation program (conventional measures plus gait training) or a Control Group (CG, n = 66) receiving 10 sessions of conventional rehabilitation (electrotherapy with magnetodiaflux, TENS, therapeutic ultrasound, low-intensity laser, plus standard kinesitherapy). Interventions were delivered daily, 5 days/week, over 2 consecutive weeks. Gait outcomes (BTS G-WALK/G-SENSOR 2) included TUG, Symmetry Index, 6MWD, and cadence; functional outcomes included VAS pain, WOMAC, and Lequesne Index. Quadriceps morphology was assessed sonographically, and a height-normalized quadriceps thickness index (QHNI) was calculated. Results. Of 130 randomized, 112 completed (93.3%). Compared with control, the intervention produced significant, clinically meaningful improvements: 6MWD increased by approximately 59 m, cadence by ~9 steps/min; TUG improved by ~2.6 s; gait symmetry by ~4–5 points; VAS pain decreased by ~1.7 points; WOMAC total by ~8.5 points; and Lequesne Index by ~2 points (all p < 0.001). QHNI showed no significant association with anthropometrics and performance measures, indicating limited value as a linear predictor at baseline; nonlinear models or subgroup analyses may be warranted. Conclusions. Both neuromuscular-focused rehabilitation and the conventional program improved gait and clinical outcomes. Integrating gait analysis with ultrasound evaluation enables comprehensive monitoring and supports personalized interventions to reduce joint loading and optimize gait mechanics in older patients with bilateral KOA.