Well wishers posted their messages of support to the former Ibrox legend on social media with many calling him an inspiration and congratulating him on his birthday.
Ricksen was diagnosed with the deadly disease in 2013 and though he was given just 15 months to live, three years later he continues to battle on and has even vowed to find a cure.
The Ibrox legend, who was part of a Rangers team that won three league titles, has continued to suppor and promote the charity MND Scotland, helping to secure £80,000 in donations.
Last month he also launched the Fernando Ricksen Foundation which was set up to “help MND patients and their families” with any money raised being used to “make the time that patients and their families have left together as comfortable as possible”.
At the time, Ricksen released a statement saying: “At the time of the diagnosis, I was given somewhere between a year and 18 months to live.
“I’m still here - and literally fighting for my life. During this period, I have found out exactly what it means to live with MND every day.
“Every hour of every day, the people closest to me - and myself - share that experience, and every day we do everything in our power to fight this demon.
“Another thing that keeps me going is the support and love from people around the world. I feel it and, believe me, it is a big help.
“Since my diagnosis, I have worked hard to raise awareness for the MND foundations. I have also used my time to raise money. But the money I have raised has been used mainly for research. And having lived with this demon for so long, I have realised that people need help now.
“All monies raised through the Fernando Ricksen Foundation will be used to help MND patients and their families. It will not go to seemingly never-ending research.”
Twitter users posted their message of support for the star with one posting: “Happy Birthday to my biggest inspiration in life Fernando Ricksen! Proper fighter!”
While a second wrote: “Happy 40th Birthday to the brave, strong and amazing man Fernando Ricksen! #KeepFightingFernando”
• You can learn more about and support the work of the foundation here.