72

Japanese Journal of Comprehensive Rehabilitation Science (2014)

Original Article

Efficacy of a novel training food based on the process model offeeding for mastication and swallowing ― A preliminary study inelderly individuals living at a residential facility ―Kazuharu Nakagawa, DDS, PhD,1 Koichiro Matsuo, DDS, PhD,1 Seiko Shibata, MD, DMSc,2
Yoko Inamoto, SLHT, DMSc,3 Yuriko Ito, DDS,2 Kazumi Abe, MPHARM,4Naoto Ishibashi, MPHARM,4 Wataru Fujii, DDS, DMSc,5 Eiichi Saitoh, MD, DMSc2
Department of Dentistry, School of Medicine, Fujita Health University, Toyoake, Aichi, Japan
Department of Rehabilitation Medicine I, School of Medicine, Fujita Health University, Toyoake, Aichi, Japan
3
Faculty of Rehabilitation, School of Health Sciences, Fujita Health University, Toyoake, Aichi, Japan4
Product Design Laboratory, Medical Foods Research Institute, OS-1 Division, Otsuka Pharmaceutical Factory,
Inc.,Tokushima, Japan
5
Department of Dentistry, Fujita Health University Nanakuri Sanatorium, Mie, Japan1
2

ABSTRACT
Nakagawa K, Matsuo K, Shibata S, Inamoto Y, Ito Y,
Abe K, Ishibashi N, Fujii W, Saitoh E. Efficacy of anovel training food based on the process model offeeding for mastication and swallowing ― a preliminary
study in elderly individuals living at a residential
facility ―. Jpn J Compr Rehabil Sci 2014; 5: 72-78.
Purpose: We examined the validity and safety of a
newly developed chew-swallow managing food(CSM) as a training material for chewing andswallowing.
Methods: Twenty-three elderly individuals (meanage: 82.8 ± 8.6 years) who followed a regular diet at aresidential facility were enrolled in this study. The
subjects ate 4 g each of CSM and puree 3 times whilebolus transport and swallowing were recorded with afiberoptic endoscope. For each trial, the number ofchewing and swallowing movements was counted. We
also identified the location of the leading edge of thefood at swallow initiation, the amount of food residue
in the oral cavity and pharynx, and the incidence of
aspiration. The differences in measurements between
CSM and puree trials were then compared statistically.
Results: With the CSM, the number of chewing andswallowing movements was significantly higher thanthat with puree and the leading edge of the food was
Correspondence: Koichiro Matsuo, DDS, PhD
Department of Dentistry, School of Medicine, Fujita Health
University, 1-98, Dengakugakubo, Kutsukake, Toyoake,
Aichi 470-1192, Japan.
E-mail: kmatsuo@fujita-hu.ac.jp
Accepted: June 12, 2014
This study was performed by the research grant of the
Otsuka Pharmaceutical Factory, Inc.
Jpn J Compr Rehabil Sci Vol 5, 2014

deeper in the pharynx at swallow initiation. There
were no significant differences in food residue or
aspiration between the 2 foods.
Conclusion: Our findings suggest that CSM has an
initial consistency that requires chewing but changes
to a texture equivalent to puree at the time ofswallowing. We are currently planning to verify thesafety and efficacy of CSM in individuals withdysphagia.
Key words: process model of feeding, mastication,swallowing, dysphagia, direct therapy
Introduction
As oropharyngeal dysphagia increases the risk ofmalnutrition and serious respiratory complications [1,2], food modification corresponding to the severity ofdysphagia promotes safe oral intake and prevents
aspiration pneumonia [3]. Classifications of texturemodified dysphagia diets have recently been releasedby the Japanese Society of Dysphagia Rehabilitation[4]. The definition of texture-modified foods andliquids has also been compared among several
countries to establish standardized internationalterminology [5].
Texture-modified food for severely dysphagic
patients has a uniform consistency that can beswallowed as a single bolus. The design of such foodis typically based on the four-stage sequential modelof command swallowing of liquid, wherein masticationand its related tongue motion is not necessary [6]. In
command swallowing, the bolus is held on the dorsal
surface of the tongue and then propelled into theesophagus through the pharynx.
Texture-modified food for mild dysphagia, on theNakagawa K et al.: Efficacy of novel training food for mastication and swallowing

other hand, requires the ability to chew [4]. To eat thiscategory of food, the material must be processed fromingestion to swallowing based on the process model offeeding [7]. Briefly, the ingested food is broken downby the masticatory movements of the jaw and mixed
with saliva. The triturated food is then placed on the
tongue surface, propelled into the oropharynx orvalleculae by a backward squeezing tongue motion,and remains there until swallowing [8].
Direct therapies for severe dysphagia usually begin
with foods of a single consistency, such as pureed orjellied food, and progress to food with a texture
needing mastication as the eating function of thepatient improves. However, single-consistency foods
and mild dysphagic diets have considerable
discrepancies in the movement of food while feeding;purees or jellies are suitable for swallowing a bolus,
but not for the process of chewing, propulsion, andeventual swallowing. Meanwhile, some specificchewing exercises using chewing gum wrapped ingauze or hard dried squid have been proposed, but thetarget of these movements is only the motion ofchewing and not the tongue rotation or backward
tongue squeezing also involved in swallowing.
Therefore, we hypothesized that if training fooddesigned according to the process model of feeding
were used from an early stage of direct therapy, thetreatment would possibly have high transference to theactual eating process and lead to more rapid
improvement of masticatory and swallowing functions.
Based on this conjecture, we invented the novel chewswallow managing food (CSM). We intended CSM tohave an initial consistency and hardness that would
require chewing but could be propelled to theoropharynx as a bolus and collected in the valleculaewith a texture equivalent to pureed food at the time ofswallowing.
The aim of this preliminary study was to examine
the validity and safety of CSM as a training food forchewing and swallowing. Using community-dwellingelderly subjects with no dysphagia, we compared
several characteristics of the feeding process for CSM
and pureed food.

73

Methods
This study’s protocol was approved by theinstitutional review board of Fujita Health University(Approval No. 13-289).
1. Subjects
The participants were elderly individuals who lived
at a residential facility. Inclusion criteria were a regular
diet and no history of dysphagia or aspiration
pneumonia. Exclusion criteria were unstable physicalstatus, structural abnormality of the oral cavity orpharynx, insufficient comprehension of instructions,food allergies, and no occlusion of the molars. The
participants provided written informed consent inadvance of the study. If a subject had cognitive
impairment, consent was obtained from both theindividual and a family member.
A total of 23 subjects (mean age: 82.8 ± 8.6 years;
13 men and 10 women) were enrolled in the study.
Their primary diagnosis was dementia (n = 13, 57%),
cerebrovascular disease (n = 6, 26%), neuromusculardisease (n = 3, 13%), and heart disease (n = 1, 4%).
2. Materials and Methods
2-1. Development of CSM
The concept of CSM was to have an initial hardness
requiring chewing that could later be propelled to theoropharynx as a bolus and collected in the valleculaewith a texture equivalent to puree at the time ofswallowing.
We first established the hardness of CSM. The lower
limit was set at 2.0 × 104 N/m2, which was the upper
limit of the Standard Regulations III for foods forpatients with swallowing difficulties released by theConsumer Affairs Agency. We considered this to be
the minimum hardness to require chewing [9]. The
upper limit of the hardness of CSM was set at 5.0 × 104
N/m2, which was the limit at which food could be
broken up using the gums without teeth as stipulated
in the Universal Design Food Concept Guidelines(UD2) [10].
We confirmed in sensory evaluations of trial foods
that a sufficient number of chewing cycles could beacquired with the established hardness limits. A target
range was not set for adhesiveness or cohesiveness

Table 1. Characteristics of CSM and pureed food.
TextureHardness (N/m2)
Cohesiveness
Adhesiveness (J/m3)

CSM*
Brown sugar lump

Stock

Soy sauce

4.2 × 104
0.4
1.8 × 103

3.9 × 104
0.4
1.8 × 103

3.7 × 104
0.4
1.5 × 103

Puree**
2.6 × 103
0.8
7.9 × 102

* Shoshokuhyo Notification No. 277.
** Universal Design Food Concept.


Jpn J Compr Rehabil Sci Vol 5, 2014

74

Nakagawa K et al.: Efficacy of novel training food for mastication and swallowing

since we did not consider them to greatly influencechewing performance. The CSM was manufactured by
Otsuka Pharmaceutical Factory, Inc., in compliancewith national food sanitation laws. The physicalproperties of CSM are shown in Table 1.
2-2. Data Acquisition
Each participant was seated comfortably upright ina chair. Videoendoscopic examination of swallowing(VE) was performed to observe the transport of food
through the pharynx, timing of swallowing, andpharyngeal residue. These events were recorded on adigital video (DV). A fiberoptic endoscope (3.6 mm indiameter, ENF TYPE P4, Olympus, Tokyo, Japan)
was inserted through the right nostril of the subject
and the tip of the endoscope was positioned behind thesoft palate to allow observation of the pharyngeal
cavity. We recorded the subjects eating the food andthe VE images with a video camera and saved theimages on a DVD (Fig. 1).
We prepared 4 g each of CSM and puree as test
foods. Participants were instructed to eat both foods 3
times while the endoscope was inserted. After the food
was placed into the mouth by the caregiver, thesubjects were instructed to eat the food normally. The
eating order of the samples in each trial was
randomized. Participants were told to swallow 3 mL ofwater if food residue was observed in the oral cavity orpharynx after swallowing.
2-3. Data Reduction
2-3-1. Number of swallows and chewing cycles
Swallowing was defined as the timing of “whiteout” in VE images and was counted for each test food.
The number of chewing cycles was considered to be
the number of cycles until the first swallow following
food intake. The number of chewing cycles wascounted on video images recorded from the external
camera (Fig. 1).

2-3-2. Location of the leading edge of the bolus atswallow initiation
The location of the leading edge of the bolus
immediately before the first swallow was identified in
VE images and classified into 5 areas based on aprevious study [11]: 1) oral cavity, the area where thefood was not observed in VE images; 2) oropharynx,
the area where the leading edge was observed in VE
images but had not reached the base of the epiglottis;
3) valleculae, the area where the leading edge hadreached the base of the epiglottis but not entered thehypopharynx; 4) hypopharynx, the area where theleading edge had entered the hypopharynx but notreached the bottom of the piriform sinus; and 5)
piriform sinus, the area where the leading edge hadreached the bottom of the piriform sinus.
2-3-3. Food residue and aspiration
We quantitatively classified food residue in the oralcavity and pharynx into 4 levels based on a previous
study [12]: 1) none; 2) punctuate/trace; 3) less thanhalf; and 4) half or more. With regard to the oral cavity,
residue was evaluated by direct observation of thedorsum of the tongue and the floor of the mouth after
the final swallow for each trial. For the pharyngeal
cavity, residue on the valleculae and piriform sinus
was evaluated in VE images just after the first and lastswallows.
Pharyngeal penetration and aspiration were evaluatedin VE images using the Penetration-Aspiration Scale(PAS) [13]. The PAS is an 8-point scale based on thedepth of penetration of food in the lower airway (1, nolaryngeal penetration; 2-5, laryngeal penetration; 6-8,
aspiration).
2-4. Data Analysis
The Wilcoxon test was used to compare differencesin the number of chewing cycles and swallows aswell as the location of the leading edge of the bolus
at swallow initiation between CSM and puree.
Comparisons of residues were performed using thechi-square test, and the Wilcoxon test was employed
for assessment of PAS scores. The critical value forrejecting the null hypothesis was p < 0.05. Statisticalanalyses were performed using SPSS version 21.0
software (SPSS Inc., IBM).
Results

Figure 1. Subject eating a test food and video
images from an endoscope were recorded
simultaneously by a digital video camera. We
counted the number of chewing cycles fromingestion to the first swallow using these images.
Jpn J Compr Rehabil Sci Vol 5, 2014

Recordings of all trials of both CSM and puree forall subjects were obtained. As a result, 138 trials were
included in the analysis. The mean (±SD) number ofswallows was significantly higher with CSM than withpuree (1.49 ± 0.63 vs. 1.23 ± 0.46, p = 0.004) (Fig.
2A). The mean number of chewing cycles until thefirst swallow was also significantly increased with
CSM (16.9 ± 10.1 vs. 2.30 ± 2.07, p < 0.001) (Fig.
2B).

Nakagawa K et al.: Efficacy of novel training food for mastication and swallowing

With the puree, the location of the leading edgeof the food at swallow initiation was primarily in theoral cavity (28/69 subjects, 40.6%), followed by
the oropharynx (23.2%), valleculae (21.7%), andhypopharynx or piriform sinus (14.5%) (Fig. 3). In
contrast, with the CSM, the leading edge of the bolus
at swallow initiation was typically observed in thevalleculae in 39.1% of subjects, followed by the oralcavity (24.6%) and the hypopharynx or piriform sinus(20.2%). The location of the leading edge of the foodat swallow initiation was significantly deeper in thepharynx with CSM than with puree (p = 0.003).
The amount of residue on the dorsum of the tongue
and the floor of the mouth after the last swallow wascomparable between CSM and puree. The amount ofresidue in the valleculae or piriform sinus was alsosimilar for the 2 test foods for the first and last swallows

Figure 2. (A) The mean (± SD) number of swallowingand (B) chewing cycles to the first swallow for CSM
and puree. Both the number of chewing cycles andswallowing were significantly increased with CSM(*p = 0.004 for swallowing and **p < 0.001 forchewing).

Figure 3. Location of the leading edge of the food for
CSM and puree. With puree, the food was mainly heldin the oral cavity, but with CSM, the food was primarily
kept in the valleculae (p = 0.003).
75(Fig. 4A, B).
Neither aspiration nor penetration was observed inover 95% of trials, and there was no significant
difference in PAS scores between the CSM and pureegroups (p = 0.083, Fig. 5). No subject aspirated the test
foods.
Discussion
1. Development of CSM
We hypothesized that performing swallowing
movements based on the process model of feeding [7]in direct therapy would improve dysphagia more
rapidly. However, conventional food requiring
chewing sometimes scatters in the pharynx due to low
cohesiveness or enters the hypopharynx before
swallow initiation from low adhesiveness [14]. Such
conditions markedly increase the risk of aspiration inpatients with dysphagia.
Our CSM was designed to have an initial hardness
that required chewing but could easily be propelled tothe oropharynx (i.e., stage II transport) and collectedin the valleculae with a texture equivalent to puree atthe time of swallowing. The texture of the CSM wasbased on the criteria for foods for patients withswallowing difficulties issued by the Consumer Affairs
Agency, which determines the ease of swallowing
certain foods by dysphagic patients, and the Universal
Design Food Concept of the Japan Care Food
Conference that defines masticatory strength [9,10].
The upper limit in Standard Regulations III for foods
for patients with swallowing difficulties (2.0 × 104 N/m2) is equal to the level of soft pureed or jellied food.
This was set as the lower limit of CSM hardness. The
upper limit of the hardness of CSM was 5.0 × 104 N/
m2, which could be broken up using the gums without
teeth as stipulated in the Universal Design Food
Concept (UD2). We found that CSM needed noticeably
more chewing than pureed food, suggesting that it
possessed our intended hardness.
When food is chewed and mixed with saliva, its
hardness decreases while its adhesiveness andcohesiveness increase [15,16]. We aimed for the
texture of the CSM at the time of bolus transport to fallwithin the range of Standard Regulations I to II for
foods for patients with swallowing difficulties, which
was equal to jelly or mousse, after chewing [9]. At thesame time, we ensured that the bolus would not be too
thin following mixture with saliva and that its
cohesiveness would be such that the food did not
scatter in the pharynx. We observed that the residue inthe oral cavity and pharynx and the depth of aspiration
did not significantly differ between the CSM andpuree. This indicated that excessive liquefaction or
decline in cohesiveness did not occur after the change
in CSM texture by chewing and transport.

Jpn J Compr Rehabil Sci Vol 5, 2014

76

Nakagawa K et al.: Efficacy of novel training food for mastication and swallowing

Figure 4. Post-swallowing residue in the (A) oral cavity and (B)pharynx. 1, residue after the first swallow; f, residue after thelast swallow. There was no significant difference in the amountof residue in the oral cavity or pharynx between CSM and puree
trials.

Figure 5. Penetration-Aspiration Scale (PAS).
No aspiration was observed for either CSM or puree,
but laryngeal penetration was witnessed in threesubjects. 1: no laryngeal penetration, 2: laryngeal
penetration, remains above the vocal folds, and isejected from the airway, 3: laryngeal penetration,
remains above the vocal folds, and is not ejected fromthe airway.
2. Efficacy of CSM as a Training Food for Chewing
and Swallowing
The mechanism of food transport from ingestion to
swallowing is different for CSM and puree. Pureed
food is swallowed based on the four-stage sequential
model [6]: the ingested puree is held in the mouth andthen propelled to the esophagus through the pharynx.
Because of its texture, it is swallowed as a bolus aftera relatively little amount of chewing. In contrast, CSM
has a texture that requires chewing performance. With
CSM, the process from ingestion to swallowing
follows the process model of feeding that includes
mastication, stage II transport, and swallowing [7].
Accordingly, the number of chewing cycles increases
significantly and swallowing occurs after themasticated food is collected and gradually propelled to
Jpn J Compr Rehabil Sci Vol 5, 2014

the pharynx, resulting in a greater number of swallows
compared with pureed food. As expected, the amountof chewing and swallowing movements was
significantly higher for CSM than puree in our cohort.
One of our main requirements for CSM wastransference and actual mastication and swallowing.
Our observed increases in the number of chewing andsubsequent swallowing movements suggest that CSM
could be used as a training food for dysphagic
individuals.
The leading edge of the food at swallow initiation
was located deeper in the pharynx with CSM than withpureed food. In our study, the leading edge of thepuree was primarily in the oral cavity. However, theleading edge of the CSM at swallow initiation was
more frequently in the oropharynx or valleculae, likely
because of oro-pharyngeal stage II transport during
mastication. These findings suggest that eating CSM
increases the number of chewing cycles and produces
more oro-pharyngeal stage II transport, with theclinical implication that direct training using CSM
targets the entire process of mastication andswallowing.
Transference is a key focus in swallowing therapies,
for which several muscle augmentation exercises havebeen reported as effective in indirect treatments[17,18]. Since maintaining a minimum level of muscle
strength in the oral cavity and pharynx is crucial todevelop mastication and swallowing ability, muscle
augmentation exercises are recognized as important
regimens for patients with dysphagia. However, thetransference of indirect exercises to actual swallowing
activities is relatively low, and so it is difficult toenhance swallowing function by these exercises only
[19]. Thus, transference is important in directswallowing therapies. Food with one consistency,

Nakagawa K et al.: Efficacy of novel training food for mastication and swallowing

such as pureed or jellied food, is a suitable starting
material for direct swallowing therapy. Regimens
using these foods are good for restoration of“swallowing”, but are less effective for “eating(mastication and swallowing)” since they do not
provoke mastication. In this study, CSM required
mastication and oropharyngeal food transport,suggesting that it could improve both mastication andswallowing in dysphagic patients.
3. Safety of CSM as a Training Food for Masticationand Swallowing
Post-swallow residue is influenced by oral andpharyngeal function as well as by food properties.
High food adhesiveness increases the risk ofpharyngeal residue due to its stickiness, while low
cohesiveness raises the risk of oral residue andaspiration due to its low rheological characteristics. In
the present study, there were no significant differencesin the amount of residue in the oral cavity or pharynx
between CSM and puree trials. PAS scores were
almost identical for both test foods, and no aspiration
was observed. Since the participants in this preliminary
study were elderly individuals following a regulardiet, the safety of CSM for dysphagic patients could
not be precisely determined. However, our findings
indicate a possible efficacy of CSM as a training foodfor mastication and swallowing with a low risk ofresidue and aspiration.
Lastly, the location of the leading edge of the food
before swallowing is also significantly affected bymasticatory performance and food properties [14].
The leading edge traveled more deeply into thepharynx with CSM than with puree, and even reached
the piriform sinus before swallowing in seven subjects
with CSM. Such deep penetration of food into thehypopharynx during chewing may increase the risk ofaspiration in dysphagic individuals with weak airway
protection. However, CSM does not share foodproperties with low viscosity two-phase food [14].
The number and duration of chewing may have been
extended in subjects with low masticatory performancein our study. With longer masticatory duration, thebolus could have more frequently reached thehypopharynx. This suggests that it is necessary tocarefully monitor patients with low masticatory
performance in future clinical studies of CSM.
Conclusion
With our novel training food for mastication andswallowing, CSM, the number of mastication andswallowing movements increased significantly andoropharyngeal stage II transport occurred more
frequently than with pureed food. In contrast, the levelof residue and laryngeal penetration did not differ
between CSM and puree. These findings imply that
CSM is an appropriate mastication and swallowing
77

training food that provokes mastication with the safetyof pureed food. Future trials are being planned toverify the efficacy of CSM in individuals withdysphagia.

References

1. Poisson P, Laffond T, Campos S, Dupuis V, BourdelMarchasson I. Relationships between oral health,dysphagia and undernutrition in hospitalised elderly
patients. Gerodontology. 2014.
2. Serra-Prat M, Palomera M, Gomez C, Sar-Shalom D,
Saiz A, Montoya JG, et al. Oropharyngeal dysphagia as arisk factor for malnutrition and lower respiratory tract
infection in independently living older persons: a
population-based prospective study. Age Ageing 2012;
41: 376-81.
3. Robbins J, Gensler G, Hind J, Logemann JA, Lindblad
AS, Brandt D, et al. Comparison of 2 interventions forliquid aspiration on pneumonia incidence: a randomized
trial. Ann Intern Med 2008; 148: 509-18.
4. Fujitani J, Uyama R, Ogoshi H, Kayashita J, Kojo A,
Takahashi K, et al. Classification of type food for
dysphagia patients by the Japanese Society of Dysphagia
Rehabilitation 2013. Jpn J Dysphagia Rehabil 2013; 17:
255-67. Japanese.
5. Cichero JA, Steele C, Duivestein J, Clave P, Chen J,
Kayashita J, et al. The need for international terminology
and definitions for texture-modified foods and thickened
liquids used in dysphagia management: foundations of a
global initiative. Curr Phys Med Rehabil Rep 2013; 1:
280-91.
6. Logemann JA. Evaluation and treatment of swallowing
disorders. 2nd ed. Austin Texas: Pro-Ed; 1998.
7. Palmer JB, Rudin NJ, Lara G, Crompton AW.
Coordination of mastication and swallowing. Dysphagia
1992; 7: 187-200.
8. Hiiemae KM, Palmer JB. Food transport and bolus
formation during complete feeding sequences on foods ofdifferent initial consistency. Dysphagia 1999; 14: 31-42.
9. Shoushokuhyou Notification, (No. 277, June 23, 2011,
Food Labeling Division, Consumer Affairs Agency.
Government of Lapan. Japanese.
10. Japan Care Food Conference. Available from: http://
www.udf.jp/about/table.html (cited 2014 April). Japanese.
11. Matsuo K, Kawase S, Wakimoto N, Iwatani K, Masuda
Y, Ogasawara T. Effect of viscosity on food transport andswallow initiation during eating of two-phase food innormal young adults: a pilot study. Dysphagia 2013; 28:63-8.
12. Yokoyama M, Okada S, Baba M, Saitoh E, Shigeta R,
Suzuki M, et al. A new jelly ―type food for dysphagia
patients ―study on its usage in direct therapy. Jpn J
Dysphagia Rehabil 2005; 9: 186-94. Japanese.
13. Rosenbek JC, Robbins JA, Roecker EB, Coyle JL, Wood
JL. A penetration-aspiration scale. Dysphagia 1996; 11:93-8.
14. Saitoh E, Shibata S, Matsuo K, Baba M, Fujii W, Palmer
JB. Chewing and food consistency: effects on bolus
Jpn J Compr Rehabil Sci Vol 5, 2014

78

Nakagawa K et al.: Efficacy of novel training food for mastication and swallowing

transport and swallow initiation. Dysphagia 2007; 22:
100-7.
15. Shiozawa K, Kohyama K, Yanagisawa K: Relationshipbetween physical properties of a food bolus and initiationof swallowing. Jpn J Oral Biol 2003; 45: 59-63.
16. Shiozawa K, Kohyama K: Effects of addition of wateron masticatory behavior and the mecanical properties ofthe food bolus. J Oral Biosci 2011; 53: 148-157.
17. Shaker R, Easterling C, Kern M, Nitschke T, Massey B,
Daniels S, et al. Rehabilitation of swallowing by exercise

Jpn J Compr Rehabil Sci Vol 5, 2014

in tube-fed patients with pharyngeal dysphagia secondary
to abnormal UES opening. Gastroenterology 2002; 122:
1314-21.
18. Robbins J, Kays SA, Gangnon RE, Hind JA, Hewitt AL,
Gentry LR, et al. The effects of lingual exercise in stroke
patients with dysphagia. Arch Phys Med Rehabil 2007;
88: 150-8.
19. Young WB. Transfer of strength and power training tosports performance. Int J Sports Physiol Perform 2006; 1:
74-83.