The purpose of this study was to investigate the effect of different baby carrying methods (including carrying in arms and carrying in a baby carrier) in the females' balance during standing and walking.

Babywearing is defined as using a supporting device that helps to keep an infant close to a caregiver's trunk.

The practice of babywearing has many benefits to both children and caregivers as it is an extension of "skin-to-skin care (SSC)" or "kangaroo care" which has well-known therapeutic benefits. Such benefits for the infant include: improve physical and cognitive state, good sleep, less likely to continuously cry, better breastfeeding, temperature stability.

For mothers, many benefits were found as well for example lower stress and anxiety levels, decrease in heart rate HR and blood pressure BP, higher breastfeeding rates, increase maternal satisfaction, increased bonding of mother with their neonate .

Despite the great advantage of infant carrying, there are many adverse effects on the musculoskeletal system and ergonomics of the mother. Women who carry their babies throughout the day will probably have similar consequences as carrying an extra load so pain and injuries will occur.

It has been reported that infant carrying in-arms caused acute muscle soreness in the ipsilateral upper limb that was used to support the infant over the left shoulder. While during the front infant carrying methods (ICMs), the pressure of the infant carrier shoulder straps caused shoulder discomfort and pain.

The front infant carrying position has the next highest fatigue score as it results in lower Metabolic equivalent (METS) and VO2max value which means that it places significant demand on the metabolic system.

It have been reported that the increased cost of carrying an infant in one's arms is the cause for the development of infant carrying tools rapidly.

Infant carrying is a form of exterogestation, just like in pregnancy, there is an alteration that swings the center of gravity of the body, shifts the postural balance, and increases the risk of falls .

Contrariwise, the usage of the carrier resulted in more similar postural control variables to the unloaded condition. Mannen and colleagues advised the use of babywearing as it provides a mechanical advantage to the caregiver.

Surprisingly, no study so far has quantified the actual balance changes with different carrying methods (including carrying in arms and carrying in a baby carrier) during typical movements of daily life, such as walking or standing upright.

Previous research has indicated that carrying externals loads elicits an increase in the center of pressure (COP) measures of postural sway during quiet standing .

Mathew W. Hill & Price reported that holding external loads during standing is an important issue for many daily and occupational activities and these external loads can affect postural stability, which is important for the mother's and fetus's safety. Also, holding a load in the hand may have restricted and/or delayed postural reactions.

From this perspective, both carrying methods are considered extra load and the question is that there any carrying methods that have an advantage over others concerning balance?

Inclusion Criteria:

1. Had normal menstrual cycles.
2. All females were recruited on a day other than mese days.
3. Their age ranged from 20 to 35 years old.
4. Their body mass index ranged from 18-30 kg/m².
5. Had no experience with babywearing or in arm-carrying methods

Exclusion Criteria:

• Subjects were excluded if they had the following criteria:

  1. Females who had irregular menstrual cycles.
  2. Females who used oral contraceptive drugs or hormonal supplementary and injections through the previous 3 months.
  3. Females who had Musculoskeletal disorders or pain in the upper and lower extremities in the prior 6 months.
  4. Females complained of knee, ankle, or back pain.
  5. Females with a severe chronic illness that interfere with balance such as vestibular dysfunction.
  6. Any health condition that could interfere with the ability to maintain balance was excluded.