## 1 Introduction  
Unilateral transfemoral amputees exhibit lower-limb asymmetry because of amputation and distinctive gait characteristics compared with healthy adults [1; 2]. They are affected to changes in suspension systems, prosthetic alignment, and prosthetic components, such as the feet, and knee joints [3; 4; 5; 6]. In transfemoral amputees, vaulting may be encountered during the prosthetic swing phase as a gait-compensatory mechanism meant to assist toe clearance. This mechanism is observed with the plantar flexion of the contralateral ankle during the single-limb support phase. [PERSON] et al. found that the contralateral limb of transfemoral amputees with vaulting produces higher ankle power during the single-support phase [7]. [PERSON] et al. stated that a significant difference in the plantar pressure-time integral under second-fourth MTP joints maintained in the intact contralateral limb in patients who were transtibial amputees may be the result of changes in gait [8]. The preservation of the contralateral limb is of critical importance, as it may impact the patient's mobility and quality of life. [PERSON] et al. studied muscle synergies between healthy subjects and transfemoral amputees, and statistically significant differences were observed particularly during the stance phase, which mainly activates plantar flexors in the gait cycle in the stance phase in TFA [9]. Technological advances that have led to the emergence of prosthetic knees with electronically controlled stance and swing phases have greatly increased the functional capabilities and safety of transfemoral amputation patients. The use of this technology can improve and increase mobility [10; 11; 12; 13] and walking speed [12; 13; 14], while reducing the use of walking aids reduces gait asymmetry [15; 16; 17]. Plantar pressure analysis is clinically effective in the diagnosis of foot deformities, the detection and treatment of gait disturbances, and the prevention of foot ulcers [18; 19]. One of the main parameters used in plantar pressure analysis is peak plantar pressure, which is considered to be the highest pressure that occurs in certain parts of the foot during the gait cycle. The instant of pressure peaks can also be calculated, allowing for the recognition of the order in which different parts of the foot are activated. However, the validity of plantar pressure analysis has not yet been determined, and its clinical applicability in field prosthetic use is not clear. [PERSON] and [PERSON] studied the ability of a plantar pressure analysis system to detect changes in the prosthetic alignment of transtibial amputees and concluded that plantar foot pressure analysis is a sensitive and applicable tool that can help clinicians measure gait parameters affected by prosthetic alignment [20]. With regard to the sound limb, although some studies have proven overloading occurs during gait movement [21; 22; 23], temporal foot roll-over features, plantar pressure distribution patterns, and the identification of specific overloaded zones have yet to be addressed. This information can assist clinicians in preventing foot plantar injuries such as blisters, callosity, and skin ulcers that occur at high-pressure peaks in the foot, and it is beneficial in gait training. Lightweight plantar pressure plates are an effective way to record these data. [PERSON] et al. indicated that unilateral TF amputees showed an asymmetrical plantar pressure distribution and that both lower extremities of patients who had undergone TF amputation were different from healthy subjects, as per plantar pressure analysis; the participants used mechanical knee joints, and the mean age of the participants was 50 [24]. The aim of this study was to measure the plantar pressure distribution under the intact limb of transfemoral amputees using microprocessor prosthetic knees (MPKs) and to evaluate possible gait compensatory mechanisms.