PMID- 37669589
OWN - NLM
STAT- Publisher
LR  - 20230929
IS  - 1873-2380 (Electronic)
IS  - 0021-9290 (Linking)
VI  - 159
DP  - 2023 Oct
TI  - During roof-to ladder transitions, walk-through extensions modify required 
      friction direction.
PG  - 111780
LID - S0021-9290(23)00351-2 [pii]
LID - 10.1016/j.jbiomech.2023.111780 [doi]
AB  - Severe and fatal falls involving ladders commonly occur during transitions across 
      the ladder and another support surface. Slipping is a common initiating event in 
      ladder falls. This study characterized the friction requirements and body 
      kinematics of descending roof-to-ladder transitions with and without a 
      walk-through extension. Healthy adults who regularly climb ladders (n = 17) 
      completed descending roof-to-ladder transitions, while foot-rung kinetics and 
      body kinematics were recorded. The peak required coefficient of friction (RCOF) 
      with respect to the plane of the shoe sole was calculated. The RCOF and body 
      angle were calculated using their resultant values and projections in the frontal 
      and sagittal planes. Foot angle was calculated in the sagittal plane. 
      Repeated-measures ANOVA determined that compared to a walk-through ladder, a 
      traditional ladder was associated with a higher RCOF in the medial-lateral (ML) 
      direction (F(1,1)((6)) = 190.07, p < 0.001) and a lower RCOF in the 
      anterior-posterior (AP) direction (F(1,16) = 11.02, p = 0.004), but had no 
      significant relationship with the resultant RCOF (F(1,16) = 0.098, p = 0.76). 
      Spearman's rho tests performed across all testing configurations identified 
      significant associations between foot angle and overall RCOF (r(s) = -0.724, 
      p < 0.001), foot angle and AP RCOF (r(s) = -0.871, p < 0.001), and frontal plane 
      body angle and ML RCOF (r(s) = 0.782, p < 0.001). Clustering in the data suggests 
      that ladder attachments reduced frontal plane kinematics, which altered the 
      direction of RCOF by reducing the medial-lateral component. These results have 
      implications for designing rungs with good friction in multiple directions and 
      the potential for body position monitoring in ladder tasks.
CI  - Copyright (c) 2023 Elsevier Ltd. All rights reserved.
FAU - Griffin, Sarah C
AU  - Griffin SC
AD  - University of Pittsburgh, Department of Bioengineering, Pittsburgh, PA 15232, 
      United States. Electronic address: scg57@pitt.edu.
FAU - Williams, Violet
AU  - Williams V
AD  - University of Pittsburgh, Department of Bioengineering, Pittsburgh, PA 15232, 
      United States.
FAU - Vidic, Natasa
AU  - Vidic N
AD  - University of Pittsburgh, Department of Industrial Engineering, Pittsburgh, PA 
      15261, United States.
FAU - Beschorner, Kurt E
AU  - Beschorner KE
AD  - University of Pittsburgh, Department of Bioengineering, Pittsburgh, PA 15232, 
      United States.
LA  - eng
PT  - Journal Article
DEP - 20230826
PL  - United States
TA  - J Biomech
JT  - Journal of biomechanics
JID - 0157375
SB  - IM
OTO - NOTNLM
OT  - Balance
OT  - Descent
OT  - Friction requirements
OT  - Ladder climbing
OT  - Slips, trips, and falls
COIS- Declaration of Competing Interest The authors declare that they have no known 
      competing financial interests or personal relationships that could have appeared 
      to influence the work reported in this paper.
EDAT- 2023/09/06 00:41
MHDA- 2023/09/06 00:41
CRDT- 2023/09/05 18:07
PHST- 2023/04/21 00:00 [received]
PHST- 2023/07/16 00:00 [revised]
PHST- 2023/08/25 00:00 [accepted]
PHST- 2023/09/06 00:41 [pubmed]
PHST- 2023/09/06 00:41 [medline]
PHST- 2023/09/05 18:07 [entrez]
AID - S0021-9290(23)00351-2 [pii]
AID - 10.1016/j.jbiomech.2023.111780 [doi]
PST - ppublish
SO  - J Biomech. 2023 Oct;159:111780. doi: 10.1016/j.jbiomech.2023.111780. Epub 2023 
      Aug 26.