One-year longitudinal test-retest reliability and natural history of grip strength among adults with cerebral palsy

<b>Abstract</b>

<b>Purpose: </b>To assess the one-year longitudinal test-retest reliability of grip
strength (GS) and characterize the natural history of GS among adults with
cerebral palsy (CP).<b></b>

<b>Methods: </b>GS was measured in adults with CP approximately one year apart for
dominant and non-dominant hands using a handheld dynamometer. Test-retest
reliability was estimated with intraclass correlation coefficients (ICC;
two-way mixed-effects, consistency model) for the full cohort and for subgroups
defined by the Gross Motor Function Classification System (GMFCS) and Manual
Ability Classification System (MACS). The natural history of GS was summarized similarly,
including proportions of who increased, maintained, or decreased GS.<b></b>

<b>Results:</b> Fifty-three adults were included (58.5% women; mean [SD] age 37.5 [13.8]
years. ICC (95% CI) was 0.92 (0.86–0.95) for the dominant hand and 0.91
(0.85–0.95) for the non-dominant hand, indicating good-to-excellent
reliability. By GMFCS subgroup, ICCs ranged 0.79–0.91 (dominant) and 0.84–0.93
(non-dominant). By MACS subgroup, ICCs ranged 0.77–0.88 (dominant) and
0.11–0.90 (non-dominant). GS change over one year varied across GMFCS/MACS and
by direction of change.<b></b>

<b>Conclusions: </b>Clinical GS demonstrates good-to-excellent one-year
longitudinal reliability in adults with CP, with lower stability for the
non-dominant hand among individuals with MACS III–V.

**摘要**

**研究目的：** 评估成人脑瘫（cerebral palsy, CP）患者握力（grip strength, GS）的1年纵向重测信度，并阐明其握力的自然病程。

**研究方法：** 采用手持肌力测试仪（handheld dynamometer），对成人脑瘫患者的利手与非利手分别进行两次握力测量，两次测量间隔约1年。分别针对全部研究队列，以及按粗大运动功能分级系统（Gross Motor Function Classification System, GMFCS）、手功能分级系统（Manual Ability Classification System, MACS）划分的亚组，采用组内相关系数（intraclass correlation coefficient, ICC；两因素混合效应一致性模型）估算重测信度。同时以类似方式总结握力的自然病程，包括握力升高、维持或下降的人群占比。

**研究结果：** 本研究共纳入53名成人患者（女性占比58.5%；平均年龄[标准差]为37.5[13.8]岁）。利手的组内相关系数（95%置信区间）为0.92（0.86~0.95），非利手为0.91（0.85~0.95），提示握力具有良好至优秀的重测信度。按GMFCS亚组分析，利手的组内相关系数范围为0.79~0.91，非利手为0.84~0.93；按MACS亚组分析，利手的组内相关系数范围为0.77~0.88，非利手为0.11~0.90。1年内握力的变化情况因GMFCS/MACS分级以及变化方向而异。

**研究结论：** 成人脑瘫患者的临床握力具有良好至优秀的1年纵向重测信度，但MACS Ⅲ~Ⅴ级患者的非利手握力稳定性较差。