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The Effect of Aquatic Physical Therapy on Children With Down Syndrome

Hartlage, Ashley PT, DPT; Nicholson, Cody PT, DPT; Silvius, Allison PT, DPT; Ennis, Beth PT, EdD, PCS

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The Journal of Aquatic Physical Therapy: September/December 2021 - Volume 29 - Issue 3 - p 73-77
doi: 10.1097/PXT.0000000000000007
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The properties of water, buoyancy, hydrostatic pressure, and fluid resistance, in conjunction with aquatic exercise, have been shown to have a positive effect on functional movements in children with neurological diagnoses.1–3 Buoyancy allows for children to make improvements in joint range of motion and strength without the influence of gravity.4,5 Hydrostatic pressure is the force of the water that is generated on the surface of the emerged object. At increased depths, this pressure increases, which can help decrease edema, improve circulation, and enhance proprioception.1,5 Fluid resistance is the force opposing an object that is dependent upon speed and surface area. This resistance can help make strength gains while remaining in a gravity-lessened environment.1,4,5 Because of the properties of water, children are able to perform activities with more confidence and ease in water than they would on land. In addition, when working with the pediatric population, enjoyment is a crucial component to help enhance their participation and motivation to therapy.3 This high motivational influence was supported by a higher attendance rate and willingness of the children to participate in therapy.1–3,6,7

As each of these properties of water has shown its respective influence, they all collectively have positive effects on improving postural control. While there is a limited body of knowledge on the use of aquatics in children with Down syndrome (DS), literature has supported the effects of aquatic therapy on children with cerebral palsy, spinal muscular atrophy (SMA) type II, hypotonia, and developmental coordination disorder, which are disorders that present with some similar limitations in body structure and function in children with DS.2,5,8,9 While there is a limited body of knowledge on the use of aquatics in children with DS, literature has supported the effects of aquatic therapy on children with cerebral palsy, SMA type II, hypotonia, and developmental coordination disorder, which are disorders that present with some similar limitations in body structure and function in children with DS.2,5,8,9 Several of these studies have shown improvement in motor skills on land along with their improvement in aquatic skills.4,8,9

Children with DS display an overall delay in motor development when compared with children developing typically. Specific impairments include decreased dynamic balance, generalized hypotonia, slowed reaction time, and a slowed somatosensory system. These impairments lead to their underlying decreased postural control.10 Hamed8 discussed the use of aquatic therapy with children who had a diagnosis of DS in order to reduce these impairments. The researcher observed that for the participants to maintain a steady balance in water, they had to engage their trunk musculature. In turn, the children developed greater postural stability. By placing the children in water, their sensory environment changes leading to constant sensory input that targets their somatosensory system, leading to development of body awareness.8 That small study also showed improvement in gait parameters using a swimming program along with a balance program on land when compared with the land program alone. This small pilot study investigated the use of a weekly individualized aquatic therapy program to address concerns with balance and postural control.



A pre/posttest design was used with each subject serving as their own control (IRB #: 719).


Inclusion criteria included children aged 2 to 8 years with a diagnosis of DS and any level of swimming ability. Exclusion criteria included severe auditory, visual, or cardiac disorders, recent surgical procedures, open wounds, infections, and significant fear of water. Participants were recruited from the local DS organization, various schools, and prior participation in other components of a local DPT (Doctor of Physical Therapy) program. A sample size of 10 children was recruited. See Table 1 for specific participant demographics. Written informed consent was obtained from the parents prior to participation. Written assent was not obtained because of the age and cognitive ability of the children.

TABLE 1 - Participant Demographics
Participant Age, y Gender Ambulatory/Nonambulatory
1 5 Female Ambulatory
2 2 Male Nonambulatory
3 7 Male Ambulatory
4 5 Female Nonambulatory
5 3 Male Ambulatory
6 2 Male Nonambulatory
7 2 Female Ambulatory
8 5 Male Ambulatory
9 5 Male Ambulatory


Each child received 1:1 (therapist:child) therapy sessions, with some children requiring a 2:1 ratio. Volunteers at each therapy session consisted of first- and second-year DPT students with CPR certification, supervised by licensed pediatric therapists. They were recruited on the basis of showing interest in the study and availability of time. Whenever possible, volunteers worked with the same child to maintain consistency.


Pediatric Balance Scale

The Pediatric Balance Scale is a modified version of the Berg Balance Test used to assess functional balance in school-aged children. The test consists of 14 tasks that are graded on a scale of 0 to 4. The overall scale is graded from 0 to 56, with a lower score representing better performance. While out of age range for some of the children, it was used to provide pre- and postintervention comparison. The minimal detectable change (MDC) is 1.59 and the minimally clinical importance difference (MCID) is 5.83.

Water Orientation Test Alyn

The Water Orientation Test Alyn (WOTA) is used to determine change in a child's adjustment and functional ability in water. The WOTA is based upon the Halliwick concept, which is a widely accepted intervention in aquatic therapy. The WOTA comes in 2 forms: WOTA-1 and WOTA-2, with the MDC for the WOTA-1 reported as 4.2. Both tests are used to evaluate postural balance, adjustment to the pool, and the ability to move and change position in the water; however, the WOTA-1 was developed for individuals with severe disabilities who have more difficulty following instructions and was the version used for this study.11


Pretest, posttest

Prior to aquatic intervention, each child was evaluated using the Pediatric Balance Scale and the WOTA-1 at the local Aquatic Center. The WOTA-1 was chosen because of young participants who could not walk and participants having difficultly following multiple step directions, although most of the participants had some form of functional mobility. After 8 consecutive aquatic invention sessions, each child was reevaluated using both measures by the same student physical therapist to observe any changes that might have occurred.

Aquatic Intervention

A series of 8 consecutive weeks of aquatic therapy was conducted, with each session held at a local aquatic center that provided lifeguards and equipment. Interventions were customized to the individual child's needs and sessions lasted on average 45 minutes, but the total time was also determined by the child's activity tolerance.4,5,8,9

Typical interventions consisted of balance, gait, and strength exercises in the pool. Balance exercises included single-leg stance, sitting or standing on a foam mat with perturbations, and reaching outside base of support. Gait exercises consisted of walking up and down a ramp, stair training, walking with ankle weights, and side stepping. Strength training included ankle weights, weighted ball play, and pouring buckets of water (Table 2).

TABLE 2 - Examples of Interventions
Exercises Description Progressions
Retrieving rings Assortment of rings distributed throughout the pool. Encouraging children to collect rings from different depths with foot or hands. Focusing on single-leg balance with foot retrieval and maintaining balance while stooping.
  1. – Increasing depth of water

  2. – Increasing number of rings to retrieve

Mat activity Focusing on maintaining dynamic balance while performing reaching, throwing, and catching activities
  1. – Perturbations

  2. – Spinning

  3. – Ring sitting → tall kneeling → standing

  4. – Climbing on/off mat

  5. – Reaching/throwing/catching outside base of support

Stair training Encouraged children to enter/leave the pool with use of stairs
  1. – Step to pattern

  2. – Reciprocal

  3. – Carrying objects

  4. – Hand rail vs no hand rail

Gait training Encouraged normalized gait pattern. Focusing on improving endurance and activity tolerance
  1. – Cruising along an 18-in platform

  2. – Ramp

  3. – Increasing depth of water

  4. – Ankle weights

  5. – Hand-held assist/handrail vs independent

  6. – Sidesteps, retro walking

Ball Toss Tossing weighted/unweighted ball with partners to increase UE strength and endurance. Improve hand-eye coordination with catching
  1. – Increase weight of ball

  2. – Increase distance of ball throw

Floating Prone and supine floating with assistance of the PT. Encouraging breath control and relaxation
  1. – Prone vs supine

  2. – Life jacket vs no life jacket

  3. – Decreasing PT assistance

Kick board Indicated for strengthen of LE while coordinating UE to maintain kick board placement
  1. – Ankle weights

  2. – Kick board placement

Jumping/climbing Encouraging children to climb out of pool using UE strength and jumping into the pool.
  1. – Seated vs standing jump

Reaching Focusing on maintain dynamic standing or sitting balance while reaching outside base of support
  1. – Sitting, kneeling, standing

  2. – Mat Play

  3. – Large vs small objects for grasping

  4. – Dumping buckets of water

Underwater weights Indicated to maintain upright posture while floating. Indicated for improving strength and endurance
  1. – Posture

  2. – Ramp walking

  3. – Ring retrieval

Abbreviations: LE, lower extremity; PT, physical therapist; UE, upper extremity.


The study started with 10 participants; however, one participant was unable to complete the study after week 5 due to a medical intervention that would not allow them to be submerged in water. There were several children who missed sessions due to illness, vacations, parent schedules, and unforeseen commitments. See Figure 1 for participant attendance.

Fig. 1.:
Number of sessions missed by participant.

Figure 2 shows the pretest and posttest data for each participant's WOTA scores. Eight of the 9 participants showed increases in their posttest scores, each of which exceeded the MDC. The WOTA consists of 13 specific tasks, and of those tasks, ability to maintain vertical and sitting positions in water showed the most improvement in the participants.

Fig. 2.:
Pretest and posttest WOTA scores. MDC: 4.2. WOTA indicates Water Orientation Test Alyn; MDC, minimal detectable change.

Figure 3 displays the pretest and posttest data for each participant's PediBERG scores. Seven of the 9 participants showed increases, of whom, 4 exceeded the MCID and all 7 exceeded the MDC. The remaining 2 participants showed no change in their posttest scores.

Fig. 3.:
Pretest and posttest PediBERG scores. MCID: 5.83; MDC: 1.59. MCID, minimally clinical importance difference; MDC, minimal detectable change.

Throughout the study, the children adapted very well to the water, researchers, and volunteers by showing more confidence and willingness to interact. Observationally, each of the children displayed improvements in balance, core strength, gait mechanics, and coordination by demonstrating progression in activities and increased tolerance. Some examples of this include improved upright stability during standing exercises, floating supine, blowing bubbles, and walking endurance. One child, in particular, increased his active participation without crying during the last 4 weeks (Figures 4 and 5).

Fig. 4.:
Activity for trunk control.
Fig. 5.:
Functional balance activity.


This study demonstrated how an individualized aquatic treatment plan improved functional activity in the water and balance on land in children with DS. The properties of water were found to aid in the improvements noted by each child. When considering the individualized plan, progressions were developed by incorporating resistance, hydrostatic pressure, and buoyancy. Multiple children demonstrated improvements in the WOTA-1 and the PediBERG by surpassing the MDC and MCID totals. The MDC is the valid numerical change in score that is statistically significant. In the WOTA-1, 8 of the 9 participants showed a significant improvement and in the PediBERG, 7 of the 9 participants showed a significant improvement. Based upon the MDC, the changes that occurred can be seen as significant. The MCID is the valid change that occurs and that is significant to the participant. In the PediBERG, 4 participants exceeded the MCID, demonstrating that the changes that occurred are deemed meaningful to the participant. It should be noted that the 3 children who made smaller amounts of change on the WOTA were also the children with smaller changes on the PediBERG. This could indicate that lack of comfort in the water led to limited participation and therefore less skill acquisition. However, it was nice to see that even small improvements could be considered both significant and meaningful.

Several factors may have contributed to the positive outcomes that were experienced. Each child received a personalized plan that addressed that individual child's activity limitations, components of both the WOTA and PediBERG outcome measures, and the child's interest in activities to improve overall therapy engagement. Each child had varying levels of skills, so the individualization was appropriate, allowing the researchers and volunteers to work on specific impairments/activities and make progressions on a case-by-case situation. It was not only beneficial but imperative for there to be fluidity between activities in order to keep the children interested and attentive.

After each session, a treatment note was completed describing what activities were completed, how the child tolerated the session, and any other pertinent information. The treatment notes were also used for the volunteers who were not familiar with the child they were working with if needed. Although the same volunteers were not able to attend every session, effort was made to keep the researcher/volunteer-child pairs consistent.

Previous research has shown that the properties of water have demonstrated improvements in overall functional mobility on land in children with decreased tone.4,8 Based upon the results, we could reasonably assume that these properties of water may also be beneficial for children with DS. Participant 6 demonstrated difficulty with ambulation on land; however, using the buoyancy and hydrostatic pressure in the pool, the participant was able to demonstrate improved attempts at ambulation noted by the evaluators and his parents while on the pool deck. Another participant, number 1, showed deficits in balance activities on the PediBERG and was given an individualized plan incorporating various balance activities in the water. The participant showed specific improvements in balance components on the PediBERG, which were able to correlate from water to land.


There were 2 children who always required a minimum of 2 volunteers due to decreased attention and safety awareness. Other children needed a second volunteer for stand by assist during certain activities. Ideally, it would have been more effective to have a 2:1 (therapist:child) ratio during all sessions to improve the quality of sessions. All volunteers were students in the DPT program; therefore, it was difficult to recruit the same volunteers to work with the same children each week due to schedules, other obligations, and prior commitments.

The parents of 2 participants got in the pool to assist with the therapy sessions: one family wanted to be involved in the treatment session for personal comfort reasons (their child not having been a part of any therapy like this in the past), and the other parent participated in the therapy session due to the child not wanting to participate unless his father was present in the pool, too.

Another limitation faced was the small size of the participant group and the difficulty with attendance of all children for all 8 therapy sessions. The pool was only available for study use one afternoon per week, which made it unrealistic to reschedule missed sessions regardless of the reason missed. Also, limited volunteers made a small group realistic but difficult to generalize to the larger population of children with DS.

Additional outcome measures to determine change in land-based activities such as strength and gait were not performed because of time limitations but would have provided more insight into the direct translation of skills from pool to land. However, studies performed by Getz et al,12 Hamed,8 and Hillier et al9 demonstrate translation of skills gained in the aquatic setting to motor skills on land in children with a variety of neurological diagnoses including DS. Items on the WOTA-1, including entering and exiting the pool, changing positions in the water, and moving along the wall of the pool, related to mobility skills. Again, these improvements were seen in the water and not formally assessed on land. Informal discussions with parents also supported skill improvement on land; however, these should be specifically addressed in future studies. A control group would have been potentially useful for comparison but would have made recruitment difficult as families wanted to participate in the pool program.

This small pilot also did not address the social benefits of aquatic activity for these children and could be addressed formally in future studies.

Finally, since we were using the therapy pool that belonged to the local aquatic facility, we had decreased space and limited equipment due to sharing the space with residents of the facility during the 4 pm session and others engaging in water activity.


This study has shown that an 8-week aquatic therapy program can lead to improvements in overall functional ability in water as well as balance skills on land in a small sample of children with DS. While not specifically measured, some improvement in mobility on land was noted through observation and parent report. Since this was a small pilot study, the results cannot be generalized to the entire population of children with DS. Further studies would need to be conducted with larger sample sizes and improved attendance in order to determine whether results can be applied to a larger group. Likewise, it would be beneficial to compare 2 groups, land-based therapy versus aquatic therapy, to more fully determine what quantitative effect aquatics had on overall functional mobility on land.


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hydrotherapy; hypotonia; gait; postural control; pediatrics

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