Assessing Infant Carriage Systems: Ground Reaction Force Implications for Gait of the Caregiver

Mathew B Brown, Caroline J Digby-Bowl, Samuel D Todd, Mathew B Brown, Caroline J Digby-Bowl, Samuel D Todd

Abstract

Objective To assess the acute alterations of anterior infant carriage systems on the ground reaction force experienced during over-ground walking. Background Previous research has identified the alterations in posture and gait associated with an increased anterior load (external or internal); however, the forces applied to the system due to the altered posture during over-ground walking have not been established. Method Thirteen mixed gender participants completed 45 over-ground walking trials at a self-selected pace under three loaded conditions (unloaded, semi-structured carrier 9.9 kg, and structured carrier 9.9 kg). Each trial consisted of a 15-m walkway, centered around a piezoelectric force platform sampling at 1,200 Hz. Differences were assessed between loaded and unloaded conditions and across carriers using paired samples t tests and repeated measures ANOVA. Results Additional load increased all ground reaction force parameters; however, the magnitude of force changes was influenced by carrier structure. The structured carrier displayed increased force magnitudes, a reduction in the time to vertical maximum heel contact, and an increased duration of the flat foot phase in walking gait. Conclusion Evidence suggests that the acute application of anterior infant carriers alters both kinetic and temporal measures of walking gait. Importantly, these changes appear to be governed not solely by the additional mass but also by the structure of the carrier. Application These findings indicate carrier structure should be considered by the wearer and may be used to inform policy in the recommendation of anterior infant carriage systems use by caregivers.

Keywords: biomechanics; gait; kinetics; loading; posture; product design.

Figures

Figure 1.
Figure 1.
Annotated typical ground reaction force trace. P1 – initial contact, P2 – impact force peak, P3 – medial peak force, P4 – max posterior braking, P5 – max heel contact, P6 – midstance, P7 – max vertical thrust, P8 – max anterior propulsive, P9 – toe off, I1 – medial impulse, I2 – braking impulse, I3 – propulsive impulse. Fx = mediolateral force; Fy = anterior posterior force; Fz = vertical force.
Figure 2.
Figure 2.
Vertical force parameter changes due to load and carrier type. aDenotes significant difference between loaded and unloaded condition. bDenotes a significant finding from repeated measures ANOVA, indicating difference between the three conditions. cDenotes significant pairwise comparison between unloaded and semi-structured. dDenotes significant pairwise comparison between unloaded and structured. eDenotes significant pairwise comparison between semi-structured and structured.

References

    1. Atwells R. L., Birrell S. A., Hooper R. H., Mansfield N. J. (2006). Influence of carrying heavy loads on soldiers’ posture, movements and gait. Ergonomics, 49(14), 1527–1537.
    1. Babywearing International. (2015). Benefits of babywearing. Retrieved from
    1. Birrell S. A., Haslam R. A. (2008). The influence of rifle carriage on the kinetics of human gait. Ergonomics, 51, 816–826. doi:10.1080/00140130701811859
    1. Birrell S. A., Haslam R. A. (2010). The effect of load distribution within military load carriage systems on the kinetics of human gait. Applied Ergonomics, 41, 585–590. doi:10.1016/j.apergo.2009.12.004
    1. Birrell S. A., Hooper R. H., Haslam R. A. (2007). The effect of military load carriage on ground reaction forces. Gait & Posture, 26, 611–614. doi:10.1016/j.gaitpost.2006.12.008
    1. Bonci C. M. (1999). Assessment and evaluation of predisposing factors to anterior cruciate ligament injury. Journal of Athletic Training, 34(2), 155–164.
    1. Branco M., Santos-Rocha R., Aguiar L., Vieira F., Veloso A. (2013). Kinematic analysis of gait in the second and third trimesters of pregnancy. Journal of Pregnancy, 2013, 718095. doi:10.1155/2013/718095
    1. Branco M., Santos-Rocha R., Vieira F. (2014). Biomechanics of gait in pregnancy. The Scientific World Journal, 2014, 527940. doi:10.1155/2014/527940
    1. Cavanagh P., LaFortune M. A. (1980). Ground reaction forces in distance running. Journal of Biomechanics, 13, 397–406.
    1. Centre for Babywearing Studies. (2016). Blog. Retrieved from
    1. Ciacci S., Di Michelea R., Mern F. (2010). Kinematic analysis of the braking and propulsion phases during the support time in sprint running. Gait & Posture, 31(2), 209–212. doi:10.1016/j.gaitpost.2009.10.007
    1. Fallowfield J. L., Blacker S. D., Willems M. E. T., Davey T., Layden J. (2012). Neuromuscular and cardiovascular response of Royal Marines recruits to load carriage in the field. Applied Ergonomics, 43, 1131–1137. doi:10.1016/j.apergo.2012.04.003
    1. Fiolkowski P., Horodyski M., Bishop M., Williams M., Stylianou L. (2006). Changes in gait kinematics and posture with the use of a front pack. Ergonomics, 49(9), 885–894. doi:10.1080/00140130600667444
    1. Frisbee S. J., Hennes H. (2000). Adult-worn child carriers: A potential risk for injury. Injury Prevention, 6, 56–58.
    1. Gathwala G., Singh B., Balhara B. (2008). KMC facilitates mother baby attachment in low birth weight infants. The Indian Journal of Pediatrics, 75(1), 43–47.
    1. Glover R. (2012). Research overview: Is there evidence to support the use of soft slings? Retrieved from
    1. Graham R. B., Smallman C. L. W., Miller R. H., Stevenson J. M. (2014). A dynamical systems analysis of assisted and unassisted anterior and posterior hand-held load carriage. Ergonomics, 58(3), 480–491. doi:10.1080/00140139.2014.978902
    1. Greenhalgh A., Sinclair J., Protheroe L., Chockalingam N. (2012). Predicting impact shock magnitude: Which ground reaction force variable should we use? International Journal of Sports Science and Engineering, 6(4), 225–231.
    1. Hsiang S. M., Jiang P., McGorry R. W. (1998). Load carrying, gait and stability. In Kumar S. (Ed.), Proceedings of the XIIIth Annual International Occupational Ergonomics and Safety Conference. Advances in Occupational Ergonomics and Safety (pp. 260–263). Amsterdam: IOS Press.
    1. Hunziker U. A., Barr R. G. (1986). Increased carrying reduces infant crying: A randomized controlled trial. Pediatrics, 77(5), 641–648.
    1. Junqueira L. D., Amaral L. Q., Lutaka A. S., Duarte M. (2015). Effects of transporting an infant on the posture of women during walking and standing still. Gait & Posture, 41(3), 841–846. doi:10.1016/j.gaitpost.2015.02.014
    1. Lloyd R., Cooke C. B. (2000). Kinetic changes associated with load carriage using two rucksack designs. Ergonomics, 43(9), 1331–1341, doi:10.1080/001401300421770
    1. Lymbery J. K., Gilleard W. (2005). The stance phase of walking during late pregnancy: Temporospatial and ground reaction force variables. Journal of the American Podiatric Medical Association, 95(3), 247–253.
    1. McCrory J. L., Chambers A. J., Daftary A., Redfern M. S. (2011). Ground reaction forces during gait in pregnant fallers and non-fallers. Gait & Posture, 34(4), 524–528. doi:10.1016/j.gaitpost.2011.07.007
    1. McCrory J. L., Chambers A. J., Daftary A., Redfern M. S. (2013). Ground reaction forces during stair locomotion in pregnancy. Gait & Posture, 38(4), 684–690. doi:10.1016/j.gaitpost.2013.03.002
    1. National Childbirth Trust. (2016). Babywearing and how to choose a sling. Retrieved from
    1. Natural Life Mom. (2012). Babywearing benefits for baby and caregivers. Retrieved from
    1. NHS. (2017). NHS growth charts. Retrieved from
    1. Novacheck T. F. (1998). The biomechanics of running. Gait & Posture, 7(1), 77–95. doi:10.1016/S0966-6362(97)00038-6
    1. Perry C. J., Kiriella J. B., Hawkins K. M., Shanahan C. J., Moore A. E., Gage W. H. (2010). The effects of anterior load carriage on lower limb gait parameters during obstacle clearance. Gait & Posture, 32(1), 57–61. doi:10.1016/j.gait post.2010.03.003
    1. Qu X., Yeo J. C. (2011). Effects of load carriage and fatigue on gait characteristics. Journal of Biomechanics, 44(7), 1259–1263. doi:10.1016/j.jbiomech.2011.02.016
    1. Schiffman J. M., Bensel C. K., Hasselquist L., Gregorczyk K. N., Piscitelle L. (2006). Effects of carried weight on random motion and traditional measures of postural sway. Applied Ergonomics, 37(5), 607–614. doi:10.1016/j.apergo.2005.10.002
    1. Sling Babies. (2011). The benefits of babywearing. Retrieved from
    1. Tessier R., Cristo M., Velez S., Giron M., de Calume Z. F., Ruiz-Palaez J. G., . . . Charpak N. (1998). Kangaroo mother care and the bonding hypothesis. Pediatrics, 102(2), e17.
    1. Urbaniak G. C., Plous S. (2013). Research randomizer (Version 4.0) [Computer software]. Retrieved from
    1. Winett R. A., Carpinelli R. N. (2001). Potential health-related benefits of resistance training. Preventive Medicine, 33(5), 503–513. doi:10.1006/pmed.2001.0909
    1. Wu C-Y., Huang H-R., Wang M-J. (2017). Baby carriers: A comparison of traditional sling and front worn, rear-facing harness carriers. Ergonomics, 60(1), 111–117. doi:10.1080/00140139.2016.1168871
    1. Wulf G., Weigelt M., Poulter D., McNevin N. (2003). Attentional focus on suprapostural tasks affects balance learning. The Quarterly Journal of Experimental Psychology Section A, 56, 1191–1211. doi:10.1080/02724980343000062

Source: PubMed

Sponsors and Collaborators

Medical Conditions

Drug Interventions

3
Subscribe