Abstract：
Maintaining normal patellar alignment is important for knee health. Altered activation of individual quadriceps muscles have been found related to patellar alignment. However, the relationships between strength and passive stiffness of the quadriceps and patellar alignment remains unexplored.
Participants aged between 60 and 80 years with activity-induced knee pain were recruited. Knee pain was quantified using an 11-point numeric rating scale. Quadriceps strength was assessed using a Cybex dynamometer and passive stiffness of rectus femoris, vastus lateralis, and vastus medialis were measured by shear-wave ultrasound elastography. Patellar alignments were assessed using MR imaging. Linear regression was used to examine relationships between quadriceps properties and patellar alignments with and without controlling for potential covariates.
Ninety-two eligible participants were assessed (71.7% females, age: 65.6 ± 3.8 years; pain scale: 4.6 ± 2.0), most of whom had knee pain during stair climbing (85.9%). We found that 17% of patellar lateral tilt angle could be explained by lower quadriceps strength (adjusted R2 = 0.117; P < 0.001), especially in females (R2 = 0.281; P < 0.001; adjusted R2 = 0.211; P < 0.001). In addition, a higher stiffness ratio of vastus lateralis/medialis accounted for 12% of patellar lateral displacement (adjusted R2 = 0.112; P = 0.008).
Quadriceps strength and relative stiffness of lateral to medial heads are associated with patellar alignment in older adults with knee pain. It suggests that quadriceps weakness and relatively stiffer lateral quadriceps may be risk factors related to patellar malalignments in the elderly.
Participants aged between 60 and 80 years with activity-induced knee pain were recruited. Knee pain was quantified using an 11-point numeric rating scale. Quadriceps strength was assessed using a Cybex dynamometer and passive stiffness of rectus femoris, vastus lateralis, and vastus medialis were measured by shear-wave ultrasound elastography. Patellar alignments were assessed using MR imaging. Linear regression was used to examine relationships between quadriceps properties and patellar alignments with and without controlling for potential covariates.
Ninety-two eligible participants were assessed (71.7% females, age: 65.6 ± 3.8 years; pain scale: 4.6 ± 2.0), most of whom had knee pain during stair climbing (85.9%). We found that 17% of patellar lateral tilt angle could be explained by lower quadriceps strength (adjusted R2 = 0.117; P < 0.001), especially in females (R2 = 0.281; P < 0.001; adjusted R2 = 0.211; P < 0.001). In addition, a higher stiffness ratio of vastus lateralis/medialis accounted for 12% of patellar lateral displacement (adjusted R2 = 0.112; P = 0.008).
Quadriceps strength and relative stiffness of lateral to medial heads are associated with patellar alignment in older adults with knee pain. It suggests that quadriceps weakness and relatively stiffer lateral quadriceps may be risk factors related to patellar malalignments in the elderly.
摘要：
背景：保持正常的髌骨对准对膝关节健康很重要。已发现个体股四头肌的激活改变与the骨对齐有关。然而,股四头肌的强度和被动刚度与髌骨对齐之间的关系仍未探索。
方法：招募年龄在60至80岁之间的活动性膝关节疼痛患者。使用11点数字评定量表量化膝关节疼痛。使用Cybex测功机和股直肌被动刚度评估股四头肌强度。股外侧肌,采用剪切波超声弹性成像技术测量股内侧肌。使用MR成像评估髌骨对齐。线性回归用于检查股四头肌特性与the骨对齐之间的关系，并控制和不控制潜在的协变量。
结果：对92名符合条件的参与者进行了评估（71.7%为女性，年龄：65.6±3.8岁；疼痛评分：4.6±2.0），大多数人在爬楼梯时膝盖疼痛(85.9%)。我们发现17％的髌骨侧向倾斜角可以解释为较低的股四头肌强度（调整后的R2=0.117；P<0.001），尤其是女性（R2=0.281;P<0.001;调整后的R2=0.211;P<0.001）。此外,较高的股外侧肌/中肌刚度比占髌骨外侧位移的12%(调整后的R2=0.112;P=0.008).
结论：在患有膝关节疼痛的老年人中，股四头肌的力量和外侧至内侧头的相对刚度与髌骨对齐有关。这表明股四头肌无力和股四头肌外侧相对较硬可能是老年人髌骨畸形的危险因素。
方法：招募年龄在60至80岁之间的活动性膝关节疼痛患者。使用11点数字评定量表量化膝关节疼痛。使用Cybex测功机和股直肌被动刚度评估股四头肌强度。股外侧肌,采用剪切波超声弹性成像技术测量股内侧肌。使用MR成像评估髌骨对齐。线性回归用于检查股四头肌特性与the骨对齐之间的关系，并控制和不控制潜在的协变量。
结果：对92名符合条件的参与者进行了评估（71.7%为女性，年龄：65.6±3.8岁；疼痛评分：4.6±2.0），大多数人在爬楼梯时膝盖疼痛(85.9%)。我们发现17％的髌骨侧向倾斜角可以解释为较低的股四头肌强度（调整后的R2=0.117；P<0.001），尤其是女性（R2=0.281;P<0.001;调整后的R2=0.211;P<0.001）。此外,较高的股外侧肌/中肌刚度比占髌骨外侧位移的12%(调整后的R2=0.112;P=0.008).
结论：在患有膝关节疼痛的老年人中，股四头肌的力量和外侧至内侧头的相对刚度与髌骨对齐有关。这表明股四头肌无力和股四头肌外侧相对较硬可能是老年人髌骨畸形的危险因素。
