People with Parkinson disease demonstrate increased gait variability, but the primary variability sources are poorly understood. People with Parkinson disease and freezing of gait (freezers) have greater gait impairments than people with Parkinson disease without freezing of gait (nonfreezers), which may relate to cerebellar dysfunction. Thirteen freezers and 31 nonfreezers completed backward, forward, and forward with dual task gait trials. Sagittal joint angle waveforms were extracted for the hip, knee, and ankle using 3D motion capture. Decomposition indices were calculated for the 3 joint combinations. Principal component analysis extracted variance sources from the joint waveforms. Freezers had significantly greater decomposition between hip-ankle (F1,42 = 5.1, P = .03) and hip-knee (F1,42 = 5.3, P = .03) movements. The principal component analysis did not differentiate freezers and nonfreezers; however, primary variance sources differed between conditions. Primary variance during forward and forward with dual task gait came from joint angle magnitude and peak angle timing. Backward gait showed primary variance from joint angle magnitude and range of motion. The results show that freezers decompose movement more than nonfreezers, implicating cerebellar involvement in freezing of gait. Primary variance differs between gait conditions, and tailoring gait interventions to address variability sources may improve intervention efficacy.

中文翻译：

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帕金森病患者的后向、前向和双重任务步态运动学的横截面分析，有和没有冻结步态。

帕金森病患者的步态变异性增加，但人们对变异性的主要来源知之甚少。患有帕金森病和冻结步态（冻结者）的人比患有帕金森病但没有冻结步态（非冻结者）的人有更大的步态障碍，这可能与小脑功能障碍有关。13 台冷冻机和 31 台非冷冻机完成了向后、向前和向前的双任务步态试验。使用 3D 运动捕捉提取髋部、膝部和踝部的矢状关节角度波形。计算了 3 个关节组合的分解指数。主成分分析从联合波形中提取方差源。冰柜在髋-踝 (F1,42 = 5.1, P = .03) 和髋-膝 (F1,42 = 5.3, P = .03) 运动之间的分解明显更大。主成分分析没有区分冷冻柜和非冷冻柜；然而，主要方差来源因条件而异。双任务步态前进和前进期间的主要方差来自关节角度大小和峰值角度计时。向后步态显示出关节角度大小和运动范围的主要变化。结果表明，冷冻者比非冷冻者更能分解运动，这表明小脑参与了步态的冻结。步态条件之间的主要方差不同，调整步态干预措施以解决变异源可能会提高干预效果。