School of Kinesiology, University of Michigan, Ann Arbor, MI, USA.
Department of Mechanical Engineering, Colorado School of Mines, Golden, CO, USA.
J Biomech. 2023 Mar;149:111485. doi: 10.1016/j.jbiomech.2023.111485. Epub 2023 Feb 6.
Due to the loss of ankle function, many people with a transtibial amputation (TTA) have difficulty maintaining balance during functional tasks. Prosthetic alignment may affect how people with TTA maintain balance as it affects ground reaction forces (GRFs) and centers of pressure. We quantified the effect of prosthetic alignment on dynamic balance during several functional tasks. Ten people with TTA and 10 controls without TTA completed tasks including walking and transitioning from a chair. Participants with TTA completed all tasks with their prescribed alignment and six shifted alignments, including ±10 mm anterior/posterior, medial/lateral, and ±20 mm in the vertical direction. For each task, we quantified dynamic balance as the range of whole-body angular momentum (H→) and quantified trunk range of motion (ROM) and peak GRFs. Compared to controls, participants with TTA using their prescribed alignment had a greater range of H→ in the sagittal plane during walking, in all planes during sit-to-stand, and in the transverse plane during stand-to-sit. These results were associated with GRF and trunk ROM differences between participant groups. Alignment only affected the range of H→ in the frontal plane during walking. The larger range for the tall alignment coincided with a greater difference in vertical GRF between intact and amputated legs compared to other alignments. Our findings suggest that people with TTA can adapt to small, translational, alignment changes to maintain similar levels of dynamic balance during chair transitions. Future work should investigate alignment changes during other tasks and in lower functioning individuals.
由于踝关节功能丧失，许多小腿截肢（TTA）患者在进行功能性任务时难以保持平衡。假肢对线可能会影响 TTA 患者的平衡能力，因为它会影响地面反作用力（GRF）和压力中心。我们定量研究了假肢对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线对线线对线对线对线对线对线线对线线线对线线对线线对线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线线的介绍
/****************************************************************
整数数组 arr
输出描述
如果整数是素数，返回 true，否则返回 false。
你可以先尝试用 Python 实现该函数，也可以使用 Java 实现。
def is_prime(n):
"""
判断一个整数是否是素数
"""
if n < 1:
return False
if n % 2!= 0:
return False
for i in range(2, n):
if n % i!= 0 and n % i % i == 0:
return False
return True
def is_prime(n):
return n > 1 and all(i % i!= 0 and n % i % 2 == 0)
print(is_prime(17))