Friday, August 22, 2014

Doll Durability: American Girls, Journey Girls and Hearts for Hearts Dolls--A Guest Review!

My next guest reviewer, Emma, emailed to ask if she could write a piece on how some of her larger-scale dolls have weathered a few years of play.  I think this is a brilliant idea.  I am always reviewing new dolls right out of the box, but that's only the first step in determining quality.  I think that the durability of a play doll over time is the true test of its worth, and this is something that I would really like to learn more about.

Not only was Emma's review idea great, but I think you'll agree that she's done a nice job of summarizing her experience with three popular brands of doll: American GirlHearts for Hearts and Journey Girls.  I am very grateful to Emma for her hard work, creativity, and professionalism in bringing this new dimension to the blog.

This topic is so interesting to me that I hope many of you will contribute your own experiences in the comments section.  I am very curious to know how other well-loved dolls have stood the test of time.  In fact, I'd love to get some photographs of your older dolls (which you can email to so that I can add them to the bottom of this review.  If we keep this discussion limited to the 18" scale dolls that would be great, but I will think about ways to add "Doll Durability" posts as a recurring feature.  That's enough chatter from me--I am excited to sit back and hear what all of you have to say on this subject.  Take it away, Emma!

American Girl dolls of various ages.
Hi everyone! I’m Emma. I am super lucky that Ms. Emily let me do a follow-up review on three different popular brands of dolls: American Girl, Hearts for Hearts, and Journey Girls. I have owned each these doll for one and a half years or longer, and I will be showing you what becomes of them after a few years of play.

I’ll review each doll's face and limbs first, then their bodies, hair, clothes, and finally how they move.

Let’s start with American Girl, as they are probably the most popular.

Here's the cover shot again, showing my six American Girls from oldest (left) to newest (right):

The oldest one (Addy) is six years old, and the newest is about two months old.

The faces stay in good condition, with only a few scratch marks. Addy has fallen down quite a few times, and she only has a few scratches.

The eyes still open and close with ease:

The only thing I’m not happy with after all these years of play is the mouth. The paint chips off around the teeth.

Here is my newest doll’s mouth as a comparison:

The head still rotates like it should, but the gap between the neck and body seems a bit more significant. Here's a six-year-old doll's neck joint:

And here's a two-month-old doll: 

See how the older doll has a larger neck gap?

The neck strings also get a little frayed over time:

The bodies have stayed in excellent condition, with no stains, rips, or holes.

The hair also stays in very nice condition. Even after all these years, it’s still easy to brush and style.

And the wigs stay firmly attached, although from all the years of brushing, perhaps the dolls don’t have quite as much hair as they used to.

The outfits stay in remarkably good condition. They haven’t frayed or ripped at all, or lost any buttons. Here is Addy’s dress as an example:

The same thing is true for bonnets and hats, but I think that they might soften over time. The older bonnet below doesn’t have the stiffness or the crisp ribbons like the newer one does:

Addy's older bonnet (left) and Caroline's newer bonnet (right).
In my experience, the shoes don’t last. The top ripped off the pair in the picture below, exposing the fabric and some of the stitching has ripped too.

However the bottoms survived with only a few scratch marks:

And they are kind-of bent and squashed on the sides. Probably from five years of taking the shoes off and putting them back on. Bummer.

It varies from doll to doll how loose the limbs get. My six-year-old Addy doll has limbs that are just fine, but my grandma’s thirteen-year-old Lindsey doll can’t stand or even lift her arm. My three year old Kanani doll has legs that are getting loose as well.  It just really varies.

So, the American girl dolls stay in pretty good condition. And most of the things that do get worn out could be fixed with a trip to the doll hospital.

Let’s move on to the Hearts for Hearts dolls.

My oldest Hearts for Hearts doll is two years old, and my youngest is five months. 

Left to right: Consuelo, Dell
Left to right:Rahel, Mosi, and Shola.
The faces are AMAZING. There are absolutely no scratch marks on any of them. Not even on Dell, even though she did three face plants on the sidewalk when I was taking pictures of her on a windy day. All the face paint is still there as well.

Hearts for Hearts "Dell."
But…the eyes. All of the Hearts for Hearts dolls come with gorgeous eye colors. Take Nahji, for example. Her eyes were originally a beautiful chocolate brown…

And now, they are turning purple! A couple of my other  Hearts for Hearts dolls’ eyes are turning purple as well. Their beautiful eyes! It’s so sad.

The torso and limbs are, again, in pretty good condition. The torso does have a few scratches, however.


The hair quality really depends on the doll. One of my doll’s hair has gotten a little harder to brush, but that’s about it.

Another one of my doll’s hair has gone completely wild and nearly impossible to style…

The outfits are in decent condition, with a few seams coming loose and several ends fraying.

Dell’s earrings are in bad condition. Most of the shiny silver paint has chipped off, turning it from silver to grey. So disappointing.

All of my Hearts for Hearts dolls still move like normal.

Overall, the Hearts for Hearts dolls don’t hold up as well as American Girl dolls, but that’s kind-of expected from a cheaper doll. The eyes are a huge bummer. I loved their eye colors and now…they are all going to turn purple. I’ll need to visit a professional to have Nahji and Consuelo’s eyes replaced. It might cost a bit more time and money to restore these dolls to what they originally were.

Finally… The Journey Girls! My oldest Journey Girl is two years, and the youngest is five months.
The faces have survived without too many scratches. So have the limbs.

Journey Girl "Kyla."

The eyes are still in great condition and colorful. That’s a step up from the Hearts for Hearts dolls, at least.

The feet are pretty dirty--Kyla’s feet have a spot on them I can’t remove:

The bodies hold up pretty well. The only really disappointing thing I have to say about how they have held up is the stuffing is oozing out of the backside. This might call for emergency surgery someday.

Her hair is still silky and smooth. It’s gotten a little harder to brush though.

Many of the clothes, for some reason, don’t look new to me. They look…dirty.

The rotational movement of the limbs is still great. I’m pretty sure that they are not strung, but after hearing what happened after Ms. Emily investigated, I’m not going to take a peek!

The Journey Girls hold up really well, especially for a thirty-dollar doll. They might even hold up better than an American Girl doll.

So, all the popular play dolls hold up decently. Eventually, they will all need to visit a professional, but that’s kind-of expected. Out of all the old age signs, the largest problem and the most
disappointing is the Hearts for Hearts doll eyes. Someday I’m going to have to get them swapped.

I’d like to say thank you so much to Ms. Emily for letting me do a guest review on her blog. It was so fun, and I loved taking pictures of all my dolls. It was a great experience!


Thank you, Emma!  And thank you to everyone who is sharing their own experiences in the comments or through email.

Shai from Dolls and Then Some sent me a few pictures of her American Girl, "Maggie" (My American Girl #33).  She writes, "I've had her for about 4 years.  She has held up pretty well but has quite a few stains and really frizzy hair. Her lip paint also seems to be wearing off. But her limbs and clothes are fine!"

My American Girl 33
Four-year-old My American Girl #33.
Thank you, Shai!  I love this last picture of Maggie outside with her glasses on, carefully inspecting a leaf.  :)

Next, Rosalind kindly offered to share pictures and thoughts about her eight-year-old American Girl doll, "Jillian."

Rosalind writes: Jillian is an American Girl Today doll. Her My American Girl counterpart is #24, I believe. I received her for my 9th birthday and I'll be turning 17 in a few days. She has never been to the American Girl doll hospital and has never had her hair styled at American Girl Place. I had her cleaned at AGP early this year for the first time.

Jillian's face paint is still intact and not very faded:

 Her limbs are still plenty tight, although her stuffing isn't very stiff which can hamper posability.

Jillian's hair is shiny and smooth, although sometimes it feels a bit dirty; her hair has never been washed.

She has a slight gap at her neck joint and some of the stuffing is showing there. Her strings aren't very frayed. 

As you can see in this next picture, she has some slight dye transfer on her thighs:

This is her original, complete meet outfit:

Socks and undies are not shown and I couldn't find the other ponytail holder. It's around here somewhere!  Everything is in wonderful condition except the ponytail holder and shoes. 

The sole of one of the shoes has changed to a greenish-blue color and the ponytail holder is stretched/unraveled and the metal is discolored.

Thank you, Rosalind!  It's great to see a doll hold up this well--especially the hair.  What a treasure Jillian is!


  1. Do not take Heart for heart girls to a park with sand. My little sister took her Zelia to ours one and she kinda fell off the merry go round or something. Anyway she now has a slight scrach on her face and I'm preety sure theres still some sand stuck in the cornor of her eyes. On the bright side there is no sign of them turning purple last I checked. She's had her for about a year or two maybe even three... also the hair is still good,but str ay whisps like to mingle with her bangs. -Gem

  2. You can remove stains on your doll's vinyl with Oxy-10 zit cream. You have to leave it on for a few weeks, but it does work. The eyes turn purple on Hearts for Hearts girls because the manufacturer used cheap acrylic eyes, and its a real shame. I know of many people suffering the same issue. It happened with the first porcelain doll I made before I knew why glass eyes are better. At least with American Girl, they'll replace the silver eye for free. I'm sure there are tutorials online for swapping out Hearts for Hearts' eyes with something higher in quality.

    I have Journey Girl Kyla too, she is so pretty and I love her meet outfit. Thanks for the review! Fantastic idea.

  3. I would definitely say AG has a TON of quality. People still love Samantha dolls that are 20 years old!!! These dolls can also be passed down to other girls and there's always the doll hospital which replaces defects for free.
    But of course you could call me biased because the only 18 in. dolls I've had experience with are AG and Madame alexander.

    1. It depends. Getting a new head or limbs because of wear or damage to the doll DOES cost money, but if there was a defect in the original doll, Mattel's pretty good about replacing those free of charge.

      BTW, it's not too terribly difficult to re-string an AG's limbs yourself once they get loose. I've re-strung a 1st edition Kaya (2002-2005?) within a couple hours with very little difficulty and only about $10 expense for supplies from the hardware store. My 22-year-old Felicity is next.

  4. Keeping your doll away from sunlight is also a good idea. I had some success using a miracle eraser on some scuff marks on a vinyl doll's face, but you should test on an area that isn't visible and press lightly avoiding all painting on the doll or that will be removed. JustMagicdolls has a site that has great doll care advice.

  5. AG is pretty good quality my oldest AG is a 1995 Kirsten I got second hand her hair is puffy and her limbs are loose but some dolls such as the our generation ones have hair that looks like a a big matted puffy mess that is imposible to un-tangle after a few years of a kid playing with it.

    1. My Felicity got that way, but only because she'd been sleeping in my bed for a year before I started to understand why dolls (and people!) need hair-brushing. I managed to restore her so that her hair looks good, but once hair is matted too badly, the texture never fully recovers.

      I'd say that kids under 8 or so really shouldn't have a long-haired AG unless you know they're going to take good care of her. OG has lower hair quality, but the upside is you don't feel as bad if the wig gets damaged.

  6. I've had my Rahel doll for about 2 years or so, and her eyes are slightly turning purple. What a bummer! :(
    I still really wonder why their eyes turn so purple though!

  7. Hi Emma! I have all the hearts for hearts girls, and I bought a couple second hand with eyes that were already turning purple. (or all blue as the case may be) When I wrote to the company about the discoloration they explained that the problem was actually a bad batch of glue that caused the ”picture” in the eye to discolor. At that time Playmates toys was very willing to replace the doll, but I know that some of the dolls have been discontinued or nearly discontinued, so there may be limited supplies of Rahel for example. I haven't found any tutorials for hfhg specifically, but you can use a hair dryer set on low to carefully warm the area around the doll's eye and then pop it out... After that its a matter soaking the eye til the picture will peel out of the back, then printing a new picture to size and putting the eye back in the socket. Of
    course its a somewhat time consuming process but so worth it for such beautiful dolls!! :)

  8. I can add that my Hearts for Hearts Lauryce developed a slightly loose neck without much play at all, but I never noticed any purple in her gorgeous eyes. :)

    1. This is a great review! That is very strange that the eyes turn purple like that on the Hearts for Hearts girls... I wonder if it is strictly just time that does it or if it's the amount of jostling or "play."

    2. I'm an adult and don't play with my hearts for hearts girls. They live in a bedoom on the north side of my house (limited sunlight). Nahji, Consuelo, Rahel, Zelia, and Lauryce are all developing purple eye. Lilian and Dell's eyes are getting bluer. Mosi and Shola are doing fine, but they are considerably newer than the rest.

    3. Wow, interesting, marjorieeeee...thanks for replying!

    4. I have four, the oldest of which is 4 years old, and have no problems :)

    5. Does anyone know what size eyes the H4H dolls use?Wanting to find a 2nd hand doll and do a Blythe style custom for my 5yr olds next bday this November .Thinking Kawii style with a cake built around her !!!If anyone has that info ,any tips for eyes or wig sizes or have a doll up for a cheap sale let me know.

    6. Does anyone know what size eyes the H4H dolls use?Wanting to find a 2nd hand doll and do a Blythe style custom for my 5yr olds next bday this November .Thinking Kawii style with a cake built around her !!!If anyone has that info ,any tips for eyes or wig sizes or have a doll up for a cheap sale let me know.

  9. I've had my Kirsten, Felicity and Kaya since '95, '99 and '03, inherited my sister's Samantha, Molly and Kailey from '97, '99 and '03, plus a bunch of more recent dolls, and I can definitely say the biggest difference is how hard you play with them and their clothes. My sister's dolls are in a little rougher shape because she was a little less careful brushing their hair, and some of their outfits show similar wear and tear. My Felicity's hair is a little but frizzy, but her shoes and socks and dresses are all in great shape with no peeling or fraying, and likewise for Kirsten and Kaya's stuff. Storage also makes a difference - keeping them somewhere climate controlled instead of somewhere where pleather and plastic constantly hear up or cool down like an unfinished attic isn't a good idea because it stresses the material.

    Kailey is the only one with loose limbs despite all six being very well loved and played with, and of my recent purchases, only Marie Grace and Cecile have had limb tightness issues. The neck gaps definitely do become more noticeable with age, but it's easy to undo the neck strings and push the heads down a little to close the gap. My Kirsten is the only one with face paint issues (except Samantha and Molly, who apparently got a makeover that didn't get totally wiped off so they have some weird pink stains that fortunately aren't too noticeable!) but she's pre-Mattel and lighter face paint is one of the downsides of the original doll.

    Also, my Addy I picked up last year with her accessories, and I think that's just how the ribbon holds up on her bonnet. Caroline's is a thicker material, Addy's seems like thin cotton so it gets wrinkled more easily.

    Just wanted to toss in my two cents/personal experience! Too bad about the Hearts for Hearts eyes, they're beautiful dolls but that doesn't seem like an easy fix. :(

  10. This is a great idea for a series of articles! It would be useful to know also who handles the dolls, what age they are and what they usually do to them.

  11. Catriona Warmington the FirstAugust 24, 2014 at 8:50 AM

    Brilliant post :o). My Josefinanis less than a month old, but already her hair is beginning to get dry. I have to brush it every single day. Bummer

  12. Catriona Warmington the FirstAugust 24, 2014 at 8:52 AM

    I meant Josefina is. Derp.

  13. When it comes to eyes it´s not only the less expensive brands that have this issue! Some brown eyed Götz dolls now look rather vampire-like with the eyes turned purple!

  14. My Mari is from 2005 - she was Marisol Luna, the Girl of the Year from that year - and her wig is definitely showing the age of time. It's lost some length. It's okay though. If need be, I will rewig her, but I love her as is. For now, she just gets monthly braid spray treatments and I brush her carefully. Because she was bought second hand, she was restrung - she was missing a tension cup so instead of that there's a large bead in one of her shoulders to play the part of the tension cup - but her limbs are all fine and so is her body.

    Elyse (MyAG #49) and Gracie (Marie-Grace) are both newer (within the past year) and their wigs are both silky and smooth.

  15. Hi! I have American Girls doll ranging from 6+ years- 1 year old. My first AG doll (Kit) and the oldest, has stood up to the test of time. Her bob is still shiny and non- frizzy, and her limbs mildly tight. My only complaints about her durability is that she is getting small shiny spots on her face. I'm not sure why the shiny spots appear or how to get rid of them, but they can be quite annoying at times. My other complaint is that her 'Sleepy eyes' (doll eyes that open when she is stood up and closes when she is layer down.) tend to stick at certain times. Kit has considerable duribility as she was handled by a little girl.

    My second oldest doll Felicity seems to be less well- made then Kit. Her eyes stick more often then Kit, and her limbs are VERY loose. Felicity's hair is in ok condition, but isn't very shiny.
    I guess depending on what AG doll you have the qulity can vary slightly. My AG dolls with curly hair are still in great condition as long as you brush their hair carefully and twist it back into its curl.

    I have one Hearts For Hearts girl that I've had for about a year or so. I haven't noticed any purple in her eyes, but I will look closer just to be sure. Dell (My H4h) has, still, REALLY silky, smooth hair and very tight limbs. Dell though hasn't been played with at all by smaller kids, so I'm not sure how well she would stand up to it.

    - Zoë from

    P.s. Whew! Sorry that was such a long comment, I just have lots to say. ;0)

  16. Hi Emily- sorry to be a little, I mean, WAY off topic, but I've been thinking of selling my Barbie doll. One of her dates says 1966 and the other 1970 something (I'm in Illinois at the moment with my daughter who lives five hours away from me, without my doll) . She has molded and painted on pink ballet shoes, is wearing small pearl earrings, has a blonde fringe, uncut but slightly dry hair and a pink gown (not entirely sure if she came in it). Do you know which doll she is and/or how much she will sell for? Thanks a lot! P:S how much will a songbird barbie, out of box but in excellent condition and original wavy curl at the end of hair, no cut hair sell for from 1995, thanks!

    1. Oooh....I am probably not the right person to ask about vintage Barbies! I don't have any idea about values, and when I am trying to identify a certain doll, I just do an extensive picture hunt on Google! Kind-of like a quest. ;)

      By any chance does your doll look like this one?

      I'll probably have to come delete this comment because of the link, so I hope you see it! Sorry I can't be more useful...

  17. Thanks, Emily! The bad news is that I just found out that apparently, the date is just the 'concept' date and not the actual manufacturing date. My songbird doll has the same date, but the box says 1995. So this doll could be anything at all. Sadly she does not look like the one pictured, but thank you for your help! :-S I'll probably either send her to Barnardo's or Michael Sobell Hospice down the road :( but since I have a songbird carriage and horse, I could put my songbird doll stuff together and in about another 20 years or so, she'll be worth about $50-80 by then. Thank you for your help! Oh, and if you ever get a BEFOREVER doll, please review her. The prices though... an extra $5 for a DOWNGRADE in Josefina's outfit? :(

  18. (sorry for my crazy long comment)My Hearts 4 Hearts girls' eyes turned purple, too :( Consuela (not sure if I spelled that right) has an almost fully purple eye, and Lauryce is starting (not sure if i spelled her name right either). This was really disappointing for me, since Hearts 4 Hearts Girls' amazing faces were why I loved them, specifically the eyes. Also, Lauryce's crimped hair has stood the test of time for years, and has been played with by smaller children. I can still brush through her hair easily, but it always remains a bit frizzy. Consuela's hair still feels nice and smooth, and I can easily comb her hair, but I can't remove all the frizz. Also, her hair is slightly rougher on the ends.

    My AG Elizabeth has survived, and after I washed and conditioned her hair, it was almost good as new. As for my My AG doll, Shelby, it's not the case. She has really curly hair, so it has a good amount of frizz even after finger styling. But then again, I have curly hair and it's like that too!

    Just wanted to share my experience! Although it would be better to compare the doll brands curly to curly haired, textured to textured, ect. as well as hair length, since that plays a big role in how the hair reacts to the test of time.

  19. Haha Anonymous, when you said crazy long comment, I thought you were that crazy robot who wrote some generic (is that the right word?) dodgy stuff about counterfeit ag dolls. Speaking of counterfeits, loved the frozen counterfeit post!!!

  20. I've said some of this elsewhere in this thread, but let's consolidate!

    My oldest AG is a Felicity that I got for Christmas in 1992. She was very well-loved and heavily played with, and even slept in my bed!

    Her sleep eyes are still in excellent condition, minus a black mark on one eyelid. Her limbs are a bit loose, but I've encountered worse and I know how to re-string them. Her hair was a matted, frizzy mess until I gave her several hair treatments. Now it looks good, but still feels frizzy.

    Her clothes all held up well, except her meet shoes--which I didn't find out were real wool until I got them out of the attic 3 years ago and found huge moth-holes in them! Her dresses look almost-new (although the ribbons on her blue Christmas dress have faded in the sun to a weird purple shade) and are still nice and sturdy. Her shoes got torn in the heel from me forcing her feet into them too hard when I was a kid, but I managed to get replacements. I also repainted her lips and teeth, which have faded pretty badly over the years. I could have gotten her a new head, but it just wouldn't be the same.

    I'd say that as long as kids are reasonably careful with the dolls, and don't deliberately damage them (I've seen some really sad abused dollies on eBay!) they can last for generations! (It might also have helped that I wasn't allowed to bring plush toys or brushable dolls outside or into the tub--both of which can be pretty bad for them!)

  21. Great review. I t's good to see the comparison.

  22. I contacted Playmates about Hearts 4 Hearts girls. They apologized and said it was a process that involved laying glass over the photo of the eye or something like that, but that the problem has been corrected now. So, I guess, the newer dolls will not have the eye problem? She also said to check the website; as Tipi may be available there

  23. I've had my Felicity for about 15 years. She was very heavily played with at first, then less and less, and spent the last ten years in the attic. I got her and her clothes out this summer and can report that they are all in excellent condition except her hair is so frizzy that the only way to make it look semi-tame is to keep it in a braid, and one of her eyes no longer opens fully when she sits upright, giving her a bit of a lazy eye. Her old vinyl snowboots and her Earth Day sandals have warped a little, and the hem of her riding outfit and cloak (both felt and simply cut, never hemmed) have frayed a bit, but everything is still wearable and most of it looks as good as the day it was bought.

  24. I have about 10 American Girl dolls-I got my oldest, Samantha, when I was around 7 or 8 years old and my newest, about 5 years ago. Some of them (especially Samantha) have frizzy/matted hair and Kit's always had a looser-than-normal left arm (although not devastatingly so-I just have to be careful with her bad arm), but otherwise they're all in very good condition. I just stood Kaya up tonight and she still stands on her own! If I get a chance to go back to AG Place (my closest one is Chicago and I took Kit and her basset hound Grace with me when I went about 10 years ago), I might take her to the doll hospital and see if they can tighten her arm, but I'm not in a rush.

  25. Hi girls!
    First,sorry for my bad English,in Brazil we speak Portuguese.
    Well,I try change a ugly purple eyes in my H4H,and the result is very good.
    Please,se pics and steps on my Flickr album Malika(H4H Rahel):
    Thank you!!
    Rosmarie Michalska

  26. Hello, do any of you guys know what size eyes do H4H wear? Pls. answer me!

    1. Hi, I don't know the size but someone sent these to me where you can buy the right size and also a tutorial on how to change them.

      The eyes for Wellie Wishers and Hearts 4 Hearts dolls are the same size and will fit just as well. I had asked the seller and she confirmed this.

  27. Children too can have Eye sight problems such as Dryness, Itching, Burning, Stinging, Watering eyes.Therefore,their eyes should be examined by pediatric eye specialists as early as it is possible.

  28. I have 6 dolls about half are knockoffs. My oldest i would say is pretty good but her hair got to tangled to brush so I cut it to above shoulders (like kits). I also have her she is my youngest doll I have had her for almost 5 months. I also have a journey girl in nice condition. I have a Caroline doll with 3 scratches on her face they aren't noticeable from far away. I have truly me doll with nice everything but her hair is frizzy. I have a my life (I think) with no problems. I also have melody she is nice also. And if you have any tips on how to get the scratches off please tell

  29. I have only one Ag doll, and I have had her for 4 years and her hair is getting frayed, but has not lost much hair, and her joints are loosening, but not to much. Overral, I think at dolls are very good-quality dolls.

    I also have one our generation doll that is about 4yrs old as well, but her neck has a slight gap that's bigger than it was when I got her, and her hair is a big mess, even though I have always brushed it. The good thing is that her joints are not loosening more than my at doll' s joints, which is remarkable.

    I have one other our generation doll, but she is brand new-i just got her at Christmas, so she does not have many problems yet, although her joints are almost too tight, and at times it is hard to move them.

  30. I love to rescue dolls I find at goodwill and other places. I have had success washing and brushing hair with regular shampoo and conditioner. Occasionally for extremely dry hair I will use a spray leave in conditioner. Another trick I have found is that tea tree oil or melaleuca oil will remove most markings on doll skin without damaging them. I have some photos but don’t see where to add them. Oh well. ��

    I have SEVERAL dolls including Madame alexanders, American Girl, Journey Girl, City Toy, and others with my favorite being city toy ... their hair stays nice for a really long time and their joints stay strong.