Dear Ed C
A great idea considering further study! I am not in the UK so I can’t comment on the programmes there but I am involved in academia.
When to start depends on the career direction you want to go in. If you are wanting to become an expert sports/MSK clinician you may want to have some clinical experience, and you should choose a course that includes a mixture of course work to advance your clinical and research.
If you are considering a research or academic career don’t make the mistake that I did of delaying your study. In most other disciplines there is no need to delay your study just to get further clinical experience. In fact this emphasis on delaying going into academia slows down the development of the professions research base. Obviously if you are wanting to pursue a research career avoid Masters with course work and get moving on a research thesis. The only exception to the early start to a research career is if you are wanting to confine yourself to clinical research – here having good experience in the clinic helps you understand what needs to be research and how. It also helps you communicate with clinicians and patients – which is essential to good clinical research. Clinicians criticise researchers for living in ivory towers - so if you have worked as a clinician in the area you are interested in you may be inclined to be more practical and relevant.
In choosing the University if it is sports/MSK skills you are wanting consider the lecturer’s background and standing in MSK therapy. If it is research your are pursuing then you need to consider a the interests of the academic staff. It is best to align yourself with a supervisor whose work you are interested in. You may also want to find out if the faculty pulls in a lot of research grants – that is a crude indicator that they are tops in their field. Also: a faculty that is flush with grants money is usually a happy faculty and this can trickle down to you in your time there. Perks such as getting paid to attend conferences where you present and having access to the best research technology can really make the experience.
In a research Masters choosing a supervisor is very important. You need to get on with them well. The relationship can make or break the experience you have. Some faculties will give you considerable freedom with your topic, while other faculties give you a choice of specific topics they want you to do. The latter while sounding more restrictive can be better providing you really like the topic. When the supervisor has chosen the topic they may be much more supportive and you may enjoy being part of a research team. Another thing to consider if you intend to publish. The expectations on publishing from your research thesis is important to consider. I would go for a faculty that encourages you publishing at the very least one paper from your thesis.
Whether to do a specific topic or a more general topic is really up to your own interests. Both are relevant to a research degree. A more specific topic may give you a clear direction for career advancement but then can limit you if you later want to change direction. For example, in some universities you can roll over your Masters to a PhD - usually that means you loose getting the Masters but you get your PhD in reduced time. To do this your initial research question is therefore very important.
Most important is to choose a topic (and supervisor who will support your topic) in something you will find fascinating. You must love your topic. You will come up against many obstacles, and times when you get discouraged so it goes a long way if you really love the topic and want to see it through.
There are some excellent books on the subject and they can help you not only with every stage of the process but also with things to consider before starting:
How to Get a PhD - 4th edition: A Handbook for Students and their Supervisors Study Skills: Amazon.co.uk: Estelle Phillips, Derek.S. Pugh: Books
This book is for PhD candidates but a lot of it is just as relevant for Masters
Research Degrees for Health Professionals How to Succeed Radcliffe: Amazon.co.uk: Richard Hays: Books
This one I have only seen briefly but it looks good.
All the best with your study