DOI: 10.5061/dryad.fn2z34v8s
title: Correlation between quadriceps activation and proprioception in patients with knee osteoarthritis

description: Objective: To investigate the correlation between the activation status of
 quadriceps muscle and the proprioceptive accuracy in patients with knee
 osteoarthritis (KOA). Methods: We included 43 outpatients diagnosed with
 KOA and 45 health subjects from October 2024 to May 2025. The correlation
 between the absolute error in knee Joint Position Reproduction (JPR) and
 the root mean square (RMS) and median frequency (MDF) of quadriceps
 surface electromyography during walking and stair climbing was analyzed.
 Results: The JPR of 45° in KOA patient is significantly higher than health
 subjects. There was no significant difference in 30° and 60° JRP between
 the two groups. While walking, there is no significant difference of the
 sEMG data in two group. While going up stair, the RMS of LVM and RVM in
 KOA group had increased activation compared with the health subjects. In
 KOA group, while going up stair, the JPR absolute error angle of 30° was
 negatively correlated with the MDF of RVL, the JPR absolute error angle of
 45° was positively correlated with the RMS of RVM, and the JPR absolute
 error angle of 60° was positively correlated with RMS of LVM and RVM.
 There are no significantly correlation in JPR absolute error angle and the
 surface electromyography of the quadriceps muscle while walking and in
 health control group. Partial correlation analysis was performed on the
 aforementioned correlated indicators with gender included as a control
 variable, and the results indicated that in women group, the JPR absolute
 error angle of 60° was positively correlated with RMS of LVM and RVM. In
 KOA group, the RMS of LVL, RVL and RVM in walking was positively
 correlated with the RMS of LVL, RVL and RVM in going up and down stair,
 and the MDF of LVL, RVL and RVM in walking was positively correlated with
 the MDF of LVL, RVL and RVM in going up and down stair. In health control
 group, the MDF of LVL, RVL and RVM in walking was positively correlated
 with the MDF of LVL, RVL and RVM in going up and down stair. Conclusion:
 This study indicated that during stair climb, KOA patients display a
 unique pattern of elevated RMS of the VM. Notable relationships were
 identified between the absolute error angles of JPR and sEMG parameters of
 VM. The pronounced positive correlations in muscle activation patterns
 between walking and stair upward and downward activities indicate a fixed,
 task-invariant neuromuscular approach in KOA patients, possibly resulting
 from compromised sensorimotor integration due to proprioceptive
 impairments. These findings offer new insights into the pathogenesis of
 KOA from a neuromuscular-sensory viewpoint, emphasizing the need
 for future rehabilitation therapies to concurrently target proprioceptive
 accuracy and the enhancement of muscle activation patterns.
description: # Correlation between quadriceps activation and proprioception in patients
 with knee osteoarthritis Dataset DOI:
 [10.5061/dryad.fn2z34v8s](https://doi.org/10.5061/dryad.fn2z34v8s) ##
 Description of the data and file structure **Surface
 Electromyography(sEMG) Data of the Quadriceps Muscle** The 8-channel
 distributed wireless electromyography acquisition system (Shenzhen Runyi
 Taiyi Technology Co., Ltd.) was utilized for data collection, with a
 sampling frequency of 2000 Hz. Subjects were prepared by cleaning the skin
 of both lower limbs with 75% alcohol, and any hair in the areas of
 electrode placement was shaved. Surface electrodes were affixed to the
 following muscles in both lower limbs: the vastus lateralis (VL), located
 at the highest point of the muscle belly in the lower third of the line
 connecting the lateral edge of the patella and the anterior superior iliac
 spine; and the VM, placed at the midpoint of the line connecting the
 medial edge of the patella and the anterior superior iliac spine. The
 electrodes were positioned on the most prominent part of each muscle
 belly, aligned with the direction of the muscle fibers. Subjects were
 instructed to remain barefoot, and the testing procedure was thoroughly
 explained to them prior to the commencement of the test to ensure their
 understanding and comfort. Maximum Voluntary Contraction (MVC)
 Standardization: Participants were instructed to perform bodyweight squats
 to their maximum comfortable depth under standardized conditions. A
 three-dimensional motion capture gait system (Opti_Knee, Innomotion Inc.,
 Shanghai, China) was used to determined the longitudinal axis of the femur
 and the longitudinal axis of the tibia create a 90-degree angle, the body
 inclines forward, and the center of gravity is situated at the base of the
 thumb on the anterior foot. The subjects maintained the squat position for
 3 seconds, then stood up straight^[15,16]^. This process was repeated
 three times to determine the MVC sEMG.  Treadmill Walking: Participants
 stood still on the treadmill and adjusted the speed between 1 km/h and 3
 km/h according to their habitual walking speeds. After 10 s of stable
 walking, the sEMG data of quadriceps and knee joint velocity data was
 collected for about 15s (15 walking gait cycles) for both knee joints. A
 synchronizer was employed to simultaneously collect sEMG data alongside
 motion capture gait system data. Walking Up and Down Steps: Subjects stood
 naturally on the ground with their legs relaxed. Upon hearing the walking
 command, the subject began to ascend the steps, first lifting the right
 thigh, followed by the left thigh, and then the right thigh again, taking
 one step at a time for a total of three steps. After reaching the third
 step, the subject remained still for one second. Upon hearing the walking
 command again, the subject then descended the steps, first lowering the
 right thigh, followed by the left thigh, and finally standing on a flat
 surface. It is important to maintain an upright trunk throughout the
 process of ascending and descending the steps. Collect the data of going
 up and down the stairs three times. ### Files and variables #### File:
 full_indicators_summary.csv **Description:**  The comprehensive data
 summary of all the subjects collected.  ##### Variables number： the id of
 subject group：0 represents health subject，1 represents KOA subject age：age
 ranges，40 represents 40-49 years old;50 represents 50-59 years old;60
 represents 60-69 years old;70 represents 70-79 years old;80 represents
 80-89 years old gender： 0 represents female，1 represents male BMI： Weight
 (kg) / [Height (m)²] K-L grade： Kellgren-Lawrence grade KOA period：
 Clinical stages of knee osteoarthritis VAS score： Visual Analogue Scale
 WOMAC score： Western Ontario and McMaster Universities Osteoarthritis
 Index 30°JPR：Absolute error angle of knee joint position  reproduction in
 30°（average value of the three measurements） 45°JPR：Absolute error angle
 of knee joint position  reproduction in 45°（average value of the three
 measurements） 60°JPR：Absolute error angle of knee joint position 
 reproduction in 60°（average value of the three measurements）
 LW_LVM_RMS%:the RMS of left vastus medialis in walk test(Normalized with
 MVC data) LS_LVM_RMS%:the RMS of left vastus medialis in up-down
 stair(Normalized with MVC data) LW_LVL_RMS%:the RMS of left vastus
 lateralis in walk test(Normalized with MVC data) LS_LVL_RMS%:the RMS of
 left vastus lateralis in up-down stair(Normalized with MVC data)
 RW_RVM_RMS%:the RMS of right vastus medialis in walk test(Normalized with
 MVC data) RS_RVM_RMS%:the RMS of right vastus medialis in up-down
 stair(Normalized with MVC data) RW_RVL_RMS%:the RMS of right vastus
 medialis in walk test(Normalized with MVC data) RS_RVL_RMS%:the RMS of
 right vastus medialis in up-down stair(Normalized with MVC data)
 LW-LVM-MDF: the MDF of left vastus medialis in walk test LW-LVL-MDF: the
 MDF of left vastus lateralis in walk test LS-LVM-MDF: the MDF of left
 vastus medialis in up-down stair LS-LVL-MDF: the MDF of left vastus
 lateralis in up-down stair RW-RVM-MDF: the MDF of right vastus medialis in
 walk test RW-RVL-MDF: the MDF of right vastus medialis in walk test
 RS-RVM-MDF: the MDF of right vastus medialis in up-down stair RS-RVL-MDF:
 the MDF of right vastus medialis in up-down stair #### File:
 full_sEMG_data_in_correct_format.zip **Description:** The compressed file
 contains all surface electromyography data, organized into three folders
 corresponding to the maximum voluntary contraction (MVC) test, walking
 test, and up-down stair test. Each folder includes 88 Excel files, with
 each file representing the data collected from an individual subject. The
 files are labeled according to the respective subject ID. ##### Variables
 Variables definition for the excel file in the compressed file, take the
 Excel file "walk data\_ (1).csv" as an example
 EMG_IMU_1_EMG_CH1:the sEMG data of left vastus medialis
 EMG_IMU_1_EMG_CH2:the sEMG data of left vastus medialis (this chennel was
 used to calculated and analysised) EMG_IMU_2_EMG_CH1:the sEMG data of left
 rectus femoris EMG_IMU_2_EMG_CH2:the sEMG data of left rectus femoris
 (this chennel was used to calculated and analysised) EMG_IMU_3_EMG_CH1:the
 sEMG data of left vastus lateralis EMG_IMU_3_EMG_CH2:the sEMG data of left
 vastus lateralis (this chennel was used to calculated and analysised)
 EMG_IMU_4_EMG_CH1:the sEMG data of left biceps femoris
 EMG_IMU_4_EMG_CH2:the sEMG data of left biceps femoris
 EMG_IMU_5_EMG_CH1:the sEMG data of left biceps femoris
 EMG_IMU_5_EMG_CH2:the sEMG data of left biceps femoris
 EMG_IMU_9_EMG_CH1:the sEMG data of right vastus medialis
 EMG_IMU_9_EMG_CH2:the sEMG data of right vastus medialis (this chennel was
 used to calculated and analysised) EMG_IMU_10_EMG_CH1:the sEMG data of
 right rectus femoris EMG_IMU_10_EMG_CH2:the sEMG data of right rectus
 femoris EMG_IMU_11_EMG_CH1:the sEMG data of right vastus lateralis
 EMG_IMU_11_EMG_CH2:the sEMG data of right vastus lateralis (this chennel
 was used to calculated and analysised) EMG_IMU_12_EMG_CH1:the sEMG data of
 right biceps femoris EMG_IMU_12_EMG_CH2:the sEMG data of right biceps
 femoris EMG_IMU_13_EMG_CH1:the sEMG data of right biceps femoris
 EMG_IMU_13_EMG_CH2:the sEMG data of right biceps femoris ## Code/software
 MATLAB(R2024a) analysis software was employed to process the
 original sEMG signals from the medial femoris and lateral femoris. The
 original electromyography signal is subjected to denoising via a 20-450 Hz
 bandpass Butterworth filter, followed by rectification and smoothing for
 preprocessing. In the task of ascending and descending stairs, the limb
 that initiates the movement on the stairs is defined as the leading phase,
 while the limb that follows subsequently is referred to as the trailing
 phase. MATLAB analysis software was then employed to derive the amplitude
 values for all exercise cycles, determine the time range of each signal
 cycle based on the raw signals, and identify the Root Mean Square (RMS)
 and the Median Frequency (MDF) for each muscle within the Support phase of
 the gait cycle (0–60%) and leading phase. Additionally, the RMS were
 normalized [RMS(walking or up stair)/RMS(MVC)] using data from the RVC
 test. ## Access information Other publicly accessible locations of the
 data: *  None Data was derived from the following sources: * None ## Human
 subjects data All the participants included have signed the informed
 consent form.