This group comprised elderly patients (≥60 years old) clinically diagnosed with Cervical Spondylosis with Myelopathy Group through radiographic findings and symptomatology. Exclusion criteria encompassed: (1) concurrent neurological disorders (e.g., peripheral neuropathy, cerebrovascular disease); (2) comorbid spinal pathologies (e.g., degenerative scoliosis, spondylolisthesis); (3) lower extremity conditions potentially impacting gait biomechanics (e.g., severe osteoarthritis, prior arthroplasty); and (4) any history of spinal or lower limb surgical interventions, thereby minimizing potential confounders.

This group comprised healthy elderly patients (≥60 years old) . Exclusion criteria encompassed: (1) concurrent neurological disorders (e.g., peripheral neuropathy, cerebrovascular disease); (2) comorbid spinal pathologies (e.g., degenerative scoliosis, LSS, LDH, spondylolisthesis); (3) lower extremity conditions potentially impacting gait biomechanics (e.g., severe osteoarthritis, prior arthroplasty); and (4) any history of spinal or lower limb surgical interventions, thereby minimizing potential confounders.

Swing Phase is a critical stage in the Gait Cycle, referring to the movement process from when the foot leaves the ground and swings forward until it makes contact with the ground again. During this phase, the lower limb completes actions such as acceleration and deceleration in the air, as well as preparing for the next support phase. In three-dimensional gait analysis, the Swing Phase is quantified using motion capture systems (such as marker points, force plates, and surface electromyography) to measure joint angles, muscle activity, and spatiotemporal parameters, providing objective data for clinical gait assessment.

Single Support Phase is a critical stage in the Gait Cycle, referring to the period when one foot fully bears the body weight while the other lower limb is in the Swing Phase.

The Double Support Phase is a crucial time stage in the gait cycle, referring to the moment during walking when both feet are simultaneously in contact with the ground. This phase holds significant importance in gait analysis, particularly in 3D Gait Analysis, where it is used to assess balance, gait stability, and neuromuscular control.

Stride Length refers to the horizontal distance between two consecutive points of contact by the same foot. It is a crucial parameter in gait analysis for evaluating the walking cycle, particularly significant in clinical rehabilitation, sports medicine, and biomechanics research.

Step length refers to the horizontal distance between two consecutive ground contact points of the heel on the same side (i.e., the forward distance from the previous heel contact point to the next heel contact point when the left/right foot takes a step).

Step Width is a crucial parameter in Gait Analysis, used to quantify gait stability and balance control during human walking. It holds significant clinical value, particularly in fields such as neuromuscular disorders, fall risk assessment, and sports injury rehabilitation.

The Gait Deviation Index is a standardized metric used to quantitatively assess the degree of gait abnormalities, calculated based on data from 3D motion analysis systems. It is widely applied in rehabilitation medicine, orthopedics, and neuroscience, particularly for gait analysis in patients with conditions such as cerebral palsy, stroke, and spinal cord injuries.

Hip joint range of motion refers to the dynamic angular changes of the hip joint in three planes of movement, quantitatively measured using a motion capture system during three-dimensional gait analysis (3D Gait Analysis). It is a critical parameter for assessing gait abnormalities, hip joint function, and neuromuscular disorders.

Knee range of motion refers to the dynamic movement range of the knee joint in the sagittal, coronal, and transverse planes quantitatively measured by a motion capture system during three-dimensional gait analysis. It is one of the core parameters for evaluating walking function, joint stability, and postoperative rehabilitation outcomes.

Ankle range of motion (AROM) refers to the dynamic movement range of the ankle joint during the gait cycle, typically quantified and assessed in three dimensions: the sagittal plane (flexion-extension), the coronal plane (inversion-eversion), and the horizontal plane (internal-external rotation). It holds significant importance for diagnosing gait abnormalities, monitoring rehabilitation outcomes, and surgical planning.

Hip joint moment refers to the biomechanical load acting on the hip joint during the gait cycle, reflecting the mechanical balance of muscles, ligaments, and bones around the joint. In three-dimensional gait analysis, it is calculated using dynamic models, with units in newton-meters (N·m) or normalized to body weight multiples (N·m/kg).

Knee joint moment is a key dynamic parameter in gait analysis, referring to the rotational force (torque) acting on the knee joint during walking or movement, which reflects the mechanical load state of the muscles, ligaments, and bones around the knee joint.

Ankle Joint Moment refers to the internal and external moments acting on the ankle joint in the sagittal, coronal, and horizontal planes, calculated through combined measurements using a 3D motion capture system and force plates during gait analysis. It reflects the dynamic load state of the muscles, ligaments, and skeletal structures surrounding the ankle joint.

Average EMG (AEMG) refers to the average amplitude value of the electrical signals from the target muscle collected via surface electromyography (sEMG) after rectification and filtering during a gait cycle (or a specific time period) in three-dimensional gait analysis, reflecting the overall intensity of muscle activity.

The integrated electromyography (iEMG) is a quantitative metric in surface electromyography (sEMG) analysis, referring to the cumulative sum of EMG signal amplitudes over a specific time period, reflecting the overall intensity of muscle activity. In three-dimensional gait analysis, iEMG is commonly used to assess the synergistic activation patterns and fatigue levels of different muscles during the walking cycle.

The root mean square (RMS) average of surface electromyography is a time-domain analysis method used in surface electromyography (sEMG) signal processing to quantify the electrical activity intensity of muscles during specific movements (such as walking or running).

The maximum root mean square of surface electromyography (RMSmax) refers to the maximum activation intensity value (unit: μV or mV) of a specific muscle during the gait cycle, obtained by processing the muscle's electrical signals collected via surface electrodes using root mean square (RMS) analysis in three-dimensional gait analysis.

Mean Power Frequency (MPF) is one of the key indicators in the frequency domain analysis of surface electromyography (sEMG), reflecting the main frequency energy distribution of motor unit action potentials (MUAPs) during muscle contraction. In 3D gait analysis, MPF is used to quantify muscle fatigue levels, neuromuscular control strategies, and functional movement states.

The median frequency of surface electromyography (sEMG) refers to the frequency point in the power spectrum where the total energy is divided into two equal parts (i.e., 50% of the energy lies above and below this frequency) through spectral analysis of the EMG signal (typically using Fast Fourier Transform, FFT).

The validated ODI is a self-administered questionnaire for evaluating back-specific functional disability, consisting of 10 items with scores from 0 to 5, and higher ODI indicates more severe disability.