Highest frequency of collected force signal
In order to determine the spectral content of your signal you can compute and display its Fourier transform. Assuming you have $N$ samples of the signal $x[n]$ sampled at $F_s = 1500$ Hz, then you can simply determine its frequency content by the following Matlab command:

Xk = fft(x ,N);


Then you can plot its spectrum to see if there is significand energy in the frequency region above $150/2 = 75$ Hz by the following code:

figure, plot ( linspace(0,Fs,N) , abs(Xk) ) ;
xlabel('Frequency [Hz]')
title('DFT Spectrum Magnitude |X[k]| of x[n]');


If there is any signifcand energy above $75$ Hz then there will be significand aliasing. However note that the sensor might have applied a $75$ Hz lowpass filter before sampling the signal, so that you can still avoid alising, but your signal will be distorted, nevertheless, as it would have beeen sampled from a lowpass filtered version of the true signal.